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Vaccine Frequently Asked Questions (FAQs)

Vaccine Prioritization

UPDATED NOV. 15: Who is eligible to receive the vaccine?

Vaccine eligibility in Pima County is open to everyone 5 and older. Only the Pfizer vaccine has been approved for 5-17 year olds. For additional registration information and news, please visit the COVID-19 vaccine information page.

Vaccine Allocation and Distribution

UPDATED AUG. 24: What does full approval of the Pfizer Vaccine mean?

The Pfizer vaccine received full FDA approval on August 23, 2021 for the prevention of COVID-19 for all people aged 16 and older. It will be marketed under the name Comirnaty. The vaccine will continue to be available under emergency use authorization (EUA) for individuals 12-15 years of age and for a third dose in certain immunocompromised individuals. The CDC’s advisory committee will meet next week to discuss the updated recommendations for this vaccine.
Full approval for a vaccine happens only after the Food and Drug Administration (FDA) has had enough time and opportunity to accumulate enough scientific evidence to prove that a vaccine’s benefits outweigh its risks. This involves making sure that enough people have been followed for a long enough time, and looking through the vaccine maker’s data from clinical trials to see if there are any safety concerns. The FDA also carefully examines every step in the vaccine manufacturing process, making sure that the company can make the vaccine safely and reliably. 
Read more from Johns Hopkins Medicine about what full FDA approval of a COVID-19 vaccine means.
See more information from the CDC about the Pfizer vaccine, and clinicians can see more information including a package insert on the FDA’s website.

UPDATED JAN. 26: What are the latest vaccination numbers for the County?

It all began when Pima County received 11,000 doses of the Pfizer vaccine in the week beginning Dec. 14, and then 15,400 Moderna vaccines arrived on Dec. 22 and were delivered directly to approved community hospitals and clinics. The state updates its data dashboard daily -- click on "vaccine administration" to find results statewide and by county.

UPDATED OCT. 28: How many doses will I need?

Both of the Pfizer and Moderna vaccines are two-dose vaccines, and the Johnson & Johnson vaccine is a single dose. If you get the two-dose series, it is very important that you get both doses so that your body develops the most protection it can to protect you against COVID-19.
On October 21, 2021, the CDC expanded booster shot eligibility for certain groups of people. Learn more about COVID-19 booster shots.
The situation is a little bit different for people who are moderately to severely immunocompromised. The CDC recommends an additional third dose of Moderna or Pfizer to improve their immune response 28 days after completion of their initial vaccine series, with the option for a later booster vaccine. Immunocompromised people who received the Johnson & Johnson vaccine should get a single booster vaccine with any of the available vaccines at least 2 months after vaccination, according to CDC guidance.

UPDATED NOV. 22: Who is eligible for a COVID-19 booster shot?

Pima County-sponsored vaccination sites will make booster vaccines available to anyone 18 and over six months after their second dose of the Pfizer or Moderna vaccines, or two months after their single shot of Johnson & Johnson. Find a Pima County-sponsored vaccine site here.

The CDC states that anyone 18-49 who received either the Pfizer or the Moderna vaccines and who got their second dose six months ago may receive a booster shot if they wish with any of the vaccine brands. Anyone aged 50 and older, or anyone 18 and older living in a long term-care setting should receive a booster.

People 18 and older who got the Johnson & Johnson vaccine at least two months ago should receive a booster shot with any of the vaccine brands.

See additional details from the CDC about COVID-19 boosters.

UPDATED SEPT. 24: What’s the difference between an additional vaccine dose and a booster dose?

An additional dose of a vaccine may be given to people who might not develop the expected protection from a vaccine. For instance, people who are moderately to severely immunocompromised may not build enough protection when they first get a vaccine. Giving them an additional dose can sometimes help bring them closer to the protection that most people develop with the regular number of vaccines. This appears to be true for some immunocompromised people with the COVID-19 vaccines. This is why the CDC recommends that these individuals consider getting an additional, third dose of either the Modena or Pfizer at least 28 days after they complete the regular 2-dose series.
A “booster” dose is slightly different. It is another dose of a vaccine given to somebody who built enough protection after vaccination, but after time (sometimes years), protection goes down, and so another dose is given to “boost” it back where it was. Tetanus, measles, mumps, rubella, and pertussis (whooping cough) are some examples of other diseases for which people commonly get vaccine booster doses.

UPDATED AUG. 4: What is the recommended interval between the first and second doses for the mRNA vaccines?

Doses are given 21 days apart for Pfizer, and 28 days apart for Moderna. The CDC recommends following this dosing schedule as closely as possible, however second doses of either Pfizer of Moderna may be administered up to 4 days earlier or any time after the recommended date.

UPDATED JULY 12: Can non-residents (snowbirds, students) get the vaccine in Arizona?

Yes. Non-residents will be vaccinated along with residents 12 and older.

UPDATED NOV. 16: Will I have a choice of which COVID-19 vaccine I receive?

All three of the vaccine types are widely available at pharmacies as well as Pima County sites and mobile clinics, for both the primary series and boosters. Please visit the Health Department’s COVID-19 Vaccine Information & Registration page for a list of vaccine locations in Pima County, vaccines offered, eligibility, and links to vaccine FAQs. To search for locations and vaccine types at pharmacies, you can also visit the ADHS website or

UPDATED FEB 25: Can veterans sign up via Southern Arizona VA Health Care?

Yes. The Southern Arizona VA Health Care System (SAVAHCS) started vaccinating Veterans 85 and older on Jan. 11. They are currently distributing COVID-19 vaccines to Veterans 65 and older.

Veterans, who are eligible based upon Centers for Disease Control (CDC) risk criteria, are being contacted directly by VA staff to schedule a COVID-19 vaccine appointment. They are also using an automated text and telephone program that connects Veterans to SAVAHCS staff to schedule an appointment.

If a Veteran expresses interest in receiving a COVID 19 vaccine, they can register at the following web link:

UPDATED NOV. 22: Can children get vaccinated for COVID-19?

Yes. The CDC recommends that everyone 5 and older get vaccinated against COVID-19. Children and teens aged 5-17 may get the Pfizer vaccine, which also comes in a pediatric dose for 5-11 year olds. Pediatric COVID-19 vaccines are widely available at Pima County Health Department clinics, mobile sites (including schools) and pharmacies. The vaccine is free and is recommended by the CDC and the American Academy of Pediatrics.
Visit the Pima County Health Department’s Vaccine information for ages 5-11 for more information specific to this age group. The CDC offers a helpful table showing which vaccines are currently approved for different age groups.

UPDATED JAN 8: How can health care providers sign up to be vaccinators in Pima County?

The Arizona Department of Health Services has a Pandemic Vaccine Provider Onboard link for vaccination providers to start the process. More information about the registration process is available via this PDF.

  • Onboarding is for providers who have cold storage, staff for administration and are willing to meet data reporting requirements set by ADHS
  • Onboarding must be fully completed to receive vaccine
  • For assistance with the tool or to check status reach out to
Check out the CDC Storage and Handling Toolkit for more information about storing and handling vaccine.

Vaccine Volunteer Efforts

UPDATED JAN. 18: I am an active or retired health professional. Can I volunteer to help with the vaccine effort?

Yes, you can and we need you!

As Pima County accelerates the COVID-19 vaccine rollout and expands regional vaccination centers, we need volunteers like you to help staff the effort to get our community vaccinated and protected against the virus.

Doctors, veterinarians, dentists, nurses, nurse practitioners, chiropractors, physician assistants, and behavioral health professionals can all help make a difference. Medical personnel interested in volunteering should register through the Medical Reserve Corps of Southern Arizona (MRCSA). Apply directly via their online application, and an MRCSA coordinator will contact you.

UPDATED JAN. 18: Can I volunteer to help the vaccination effort even if I don’t have an active medical license?

Yes, you can!

You don’t have to administer shots to support the vaccine rollout. Pima County has partnered with the Arizona Emergency System for Advance Registration of Volunteer Health Professionals (AZ-ESAR-VHP) to offer volunteer opportunities.

To volunteer, visit their online platform, click on the big blue “Register Now” button, select “Add Organizations” and choose Pima County. They will then notify you regarding opportunities via the email address you provide.

Another option to help is by giving blood, if you’re in a position to be able to do so. The American Red Cross is reporting a shortage in blood donations, and you can schedule an appointment here.

Vaccine Safety

UPDATED AUGUST 27: Are the COVID-19 vaccines safe?

Yes they are. To receive approval under the FDA’s Emergency Use Authorization (EUA) process, the vaccine makers had to meet rigorous scientific regulatory standards and show evidence from tens of thousands of participants in clinical trials proving that their vaccines worked and were safe. 

Recently, the Pfizer COVID-19 vaccine received full FDA approval for those 16 years and over. This happens only after the Food and Drug Administration (FDA) has had enough time and opportunity to accumulate enough scientific evidence to prove that a vaccine’s benefits outweigh its risks. This involves making sure that enough people have been followed for a long enough time, and looking through the vaccine maker’s data from clinical trials to see if there are any safety concerns. The FDA also carefully examines every step in the vaccine manufacturing process, making sure that the company can make the vaccine safely and reliably. Read more from Johns Hopkins Medicine about what full FDA approval of a COVID-19 vaccine means

Pima County Health Director Dr. Theresa Cullen stated, "We're optimistic that the FDA's full approval of Pfizer's COVID-19 vaccine for those 16 and over will alleviate any concerns for people who were hesitant about the vaccine, even though the emergency use authorization met rigorous scientific standards. The science is clear. With more than 200 million Americans having received at least one dose of a COVID-19 vaccine, the public can be very confident in their safety and effectiveness. The vaccines are our best tool against the pandemic.”

Learn more about the safety of COVID-19 vaccines and about the many existing and new vaccine safety monitoring systems that are being utilized. 

UPDATED AUG. 4: What do we know about myocarditis and vaccines?

Since April, the CDC and its partners continue to actively monitor cases of myocarditis and pericarditis occurring after vaccination with the Pfizer and Moderna COVID-19 mRNA vaccines. Myocarditis is inflammation of the heart muscle; pericarditis is inflammation of the outer heart lining. These can occur when the body’s immune system responds to infection or some other trigger.

These cases remain rare and have been seen primarily in male adolescents and young adults 16 and older, typically within several days of vaccination, and more commonly after the second dose than after the first. Most patients who sought care felt better following anti-inflammatory medication and rest. Read more from the CDC about myocarditis and pericarditis and the mRNA COVID-19 vaccines.

The known and potential benefits of vaccination outweigh the known and potential risks of COVID-19 infection. The CDC, the American Academy of Pediatrics, and many other medical organizations stress the vaccines are safe and effective, that the benefits of vaccination far outweigh any risks, and continue to recommend COVID-19 vaccination for people 12 and older. In a statement from the nation’s leading doctors, nurses, and public health leaders they advise:

The facts are clear: this is an extremely rare side effect, and only an exceedingly small number of people will experience it after vaccination. Importantly, for the young people who do, most cases are mild, and individuals recover often on their own or with minimal treatment. In addition, we know that myocarditis and pericarditis are much more common if you get COVID-19, and the risks to the heart from COVID-19 infection can be more severe.

Symptoms to watch for after vaccination which might signal myocarditis or pericarditis include:
  • Chest pain 
  • Shortness of breath 
  • Feelings of having a fluttering, pounding, or fast-beating heart
If you or your child have any of these symptoms within a week after COVID-19 vaccination, seek medical care.

The CDC offers clinical guidance for healthcare providers on myocarditis and pericarditis among adolescents and young adults. It is important that healthcare providers report all post-vaccination cases of myocarditis or pericarditis to the Vaccine Adverse Event Reporting System (VAERS). For more on myocarditis and adverse effects from any of the COVID-10 vaccines, visit the CDC’s Selected Adverse Events Reported after COVID-19 Vaccination page.

UPDATED AUG. 4: What do we know about the Johnson & Johnson vaccine?

Unlike the Pfizer and Moderna vaccines that use single strands of genetic material called mRNA inside a special fat coating, the Johnson & Johnson vaccine works by using strands of DNA inside something called an “adenovirus.” Adenoviruses are common viruses like those that cause the common cold, but this virus was changed so it cannot make you sick. Just like the Pfizer and Moderna vaccines, this vaccine causes the body’s immune system to build antibodies against the virus that causes COVID-19.

The Johnson & Johnson vaccine is also a single-dose vaccine, which might make it easier for many people. It does not need the special handling the other vaccines do, making it simpler to ship and to store.

In a study of about 40,000 people in the U.S., Latin America and South Africa, the vaccine was found to be 72% effective in the U.S. and 66% effective overall in preventing moderate to severe COVID-19 disease. Side effects reported in clinical trials were mild or moderate, and most commonly were pain at the vaccine site, headache, fatigue and muscle pain. 

There have been instances of rare but potentially serious side effects with this vaccine, such as a rare kind of blood clot. There have also been reports of a rare neurological disorder called Guillain Barré syndrome, or GBS. It can cause muscle weakness and sometimes paralysis, that is usually reversible, and has occurred in some people after receiving this vaccine. In most of these people, it occurred within 42 days of getting vaccinated. The FDA has updated Johnson & Johnson fact sheets for patients and providers that discuss these potential effects and what to watch out for.
It is important to understand that the risk of having these adverse events is very low. The FDA and CDC have determined that the benefits of vaccination with the Johnson and Johnson vaccine outweigh the risks of potential adverse effects.

Updates to safety concerns and potential adverse events for all of the COVID-19 vaccines can be found at the CDC’s Safety of COVID-19 Vaccines and Selected Adverse events pages.

UPDATED AUGUST 27: What is an Emergency Use Authorization?

An Emergency Use Authorization (EUA) is a process the Food and Drug Administration (FDA) uses to make medical treatments, including vaccines available during a public health emergency, such as a pandemic. For the FDA to issue an EUA for a vaccine, the vaccine makers must first submit scientific evidence from rigorous studies using tens of thousands of research volunteers. The makers have to prove to the FDA that their vaccines are safe and that they work. EUA’s were granted for all 3 COVID-19 vaccines used in the U.S. - Pfizer, Moderna and Johnson & Johnson. 

After increasing numbers of people are followed for a long enough time, and scientific evidence accumulates continuing to confirm the safety, effectiveness and quality of the vaccine, the vaccine manufacturer is allowed to apply for full approval. Pfizer did this for its COVID-19 vaccine, and after careful review, the FDA granted full approval for the Pfizer vaccine for use in people 16 years and over. 

UPDATED AUG. 10: What are the benefits of getting a COVID-19 vaccine?

Vaccination will help keep you from getting sick. COVID-19 can be an unpredictable, serious, even fatal illness, and the vaccines are safe and extremely effective at preventing illness, hospitalization and death. Getting vaccinated will help you avoid severe illness from the variants, including the Delta variant. (For the small proportion of fully vaccinated people who do get the Delta variant, the infection tends to be mild.) If you avoid getting infected with the virus, you can also avoid spreading it to those around you.
If you have had COVID-19 before, getting vaccinated helps you build better protection against becoming reinfected, especially against the variants. A recent study found that you are twice as likely to get infected again with COVID-19 if you are unvaccinated.
Another benefit to being fully vaccinated is being able to participate in many of the activities you did before the pandemic.
Want to know more about the vaccines? Health experts at the Yale School of Medicine have mapped out a comparison of COVID-19 vaccines.

UPDATED SEPT. 30: What should I expect after getting the vaccine -- are there side effects?

Possible side effects may include pain and swelling on the arm where you got the shot. You may also get a fever, chills, tiredness, muscle pain, nausea, or a headache. These side effects may affect your ability to do daily activities, but they should go away in a few days. These are all normal signs that your body is building protection against the virus. Some people feel no side effects at all. People who received a booster shot of the Pfizer COVID-19 vaccine reported effects that were mild to moderate, and similar to those with their second shot. 
The COVID-19 vaccines are safe and effective and millions of people in the U.S. have received them. Serious side effects after COVID-19 vaccination have been reported, but are rare. The COVID-19 vaccines have been the most intensely studied vaccines in history, and the CDC and FDA closely monitor their safety.
It takes 2 weeks to build protection from a virus after getting vaccinated. You are considered fully vaccinated 2 weeks after your second dose of the Pfizer and the Moderna vaccine, or 2 weeks after you get the Johnson & Johnson vaccine. It is important that you keep following all of the steps to protect yourself and others from COVID-19 during the 2 weeks while your body is building protection.

UPDATED AUG. 17: How do I report an adverse reaction to the vaccine?

If you are a patient, please let your health care provider know about your symptoms first. We strongly urge both health care providers and patients to report any adverse reactions via the Vaccine Adverse Event Reporting System.

Additionally, at the time of vaccination, you will be given a vaccine record card with information about how to register and use the text-based tool v-safe. Registration is completely voluntary and provides personalized check-ins, surveys, and a reminder to let you know when it is time to get your second shot (for Pfizer or Moderna vaccines). Depending upon your responses, someone from the CDC may call to check on you.

UPDATED FEB. 24: I didn’t get any side effects after the COVID-19 vaccine-does that mean it’s not working?

No, this doesn’t mean your vaccination isn’t working.

Tara Parker-Pope, award-winning consumer health writer for The New York Times explains a lack of vaccine side effects this way:
"Just as some people experience side effects from medications and some don’t, people have varied reactions to vaccines. While we tend to hear only about the unpleasant reactions after the vaccine, a lot of people experience only mild discomfort or no symptoms at all after getting the shot.

“In the Pfizer trial, for instance, about half the participants developed fatigue. Other side effects occurred in at least 25 to 33 percent of patients, including headaches, chills and muscle pain. That means that half or more of the participants did not have those side effects, and yet the overall efficacy of the vaccine was 95 percent, suggesting that a lack of side effects does not mean a vaccine isn’t working.

"We also know that older people tended to report fewer side effects than younger people, probably because aging immune systems aren’t as strong. As people age, bodily defenses against pathogens weaken, and the response to vaccines also falters. But in the Pfizer and COVID vaccine trials, older people still produced adequate levels of antibodies, indicating a strong immune response after the vaccine. If you don’t have side effects after your shot, be glad you are one of the lucky ones and don’t worry.”

Answers to All Your Questions About Getting Vaccinated for Covid-19 The New York Times, updated regularly.

Can the COVID vaccine give me COVID?

No. There are no vaccines near approval that use live virus, and a COVID-19 vaccine will not cause you to test positive for COVID-19. The goal of the vaccine is to provide your body with the tools it needs to fight the COVID-19 virus if you were to get infected.

UPDATED AUG. 4: Will getting a COVID-19 vaccine cause me to test positive for COVID-19 on a viral test?

No. None of the vaccines will make you test positive on the viral tests (like PCR or antigen), because these tests check to see if you have a current infection. The vaccines cannot cause a COVID-19 infection. After you get vaccinated, you may test positive on some COVID-19 serology (antibody) tests. That is because these tests check for a protective immune response, which is the goal of immunization.

UPDATED OCT. 12: Do people who had COVID-19 still need the vaccine? Isn't natural immunity better?

COVID-19 is an evolving pandemic, and as such, research and knowledge may change. We know that the vaccines are safe and effective against serious illness, hospitalization and death from COVID-19, including against the Delta variant. Here is additional information that we know about vaccination following COVID-19 illness.
Health experts already know the vaccines give your immune system a powerful boost against the virus and reduce your chances of catching COVID-19 again. A recent study in Kentucky compared natural immunity alone to natural immunity plus vaccination and found that people who had COVID-19 and were unvaccinated were more than twice as likely to get reinfected. That means people who are vaccinated after infection have less than HALF the risk of reinfection as people who rely on natural immunity by itself.
There is also evidence suggesting that vaccination may help those suffering “long haul” post-COVID conditions. Studies at Yale University found that as many as 30-40% of those vaccinated have reported improvements in their symptoms. In a survey conducted by the UK advocacy group LongCovidSOS, the University of Exeter and the University of Kent, 57% of participants reported at least some improvement in symptoms following vaccination. 
If natural immunity by itself were enough, we would expect to see countries with low vaccination rates and high levels of natural infection (and thus natural immunity) seeing an end to their pandemic. This is not what is happening, however.
Not everyone who recovers from COVID-19 will actually develop protective immunity against the disease. We do not know who will and who will not develop this protection. Researchers discovered that a third of people who had COVID-19 failed to create protective antibodies against SARS-CoV-2. Additionally, antibodies associated with natural immunity from a previous infection may not protect against other variants of the virus.
Health experts with the Arizona Department of Health Services, the Pima County Health Department, and the CDC recommend that eligible individuals get the vaccine, even if they have had COVID-19. Learn more about the benefits of getting a COVID-19 vaccine, and find out where to get one.

UPDATED OCT. 19: Should fully vaccinated people get tested or quarantine after exposure to someone with suspected or confirmed COVID-19?

Fully vaccinated people who have been in close contact with someone with suspected or confirmed COVID-19 should be tested 5-7 days after exposure, even if they themselves do not have symptoms. They should wear a mask when in indoor public places for 14 days, or until they get a negative test result, and watch for symptoms for 14 days. Most fully vaccinated people without symptoms who follow the guidance above do not need to quarantine or restrict themselves from work after exposure to known or suspected COVID-19.
Those living with people with weakened immune systems, or who are unvaccinated or at increased risk for severe illness, may want to wear a mask at home for 14 days after a known exposure, or until they get a negative test result. 
Any fully vaccinated person who develops COVID-19 symptoms should isolate from others and follow their health care provider’s guidance. The CDC offers additional guidance for people who have been fully vaccinated.

UPDATED SEPT. 30: Should I get the vaccine if I am pregnant or breastfeeding?

Yes. The CDC urgently recommends COVID-19 vaccination as soon as possible if you are pregnant, trying to become pregnant were recently pregnant, or are breastfeeding. If you are or recently were pregnant, you are at increased risk of serious illness from COVID-19. Serious illness can mean that you may need to be hospitalized, might need a ventilator to help you breathe, and that you could die. COVID-19 infection also increases your risk for pregnancy complications such as preterm birth and stillbirth.
As of September 27, 2021, there were over 125,000 confirmed cases of COVID-19 in people who were pregnant, with over 22,000 hospitalized and 161 deaths. Approximately 97% of those hospitalized individuals were unvaccinated. 
COVID-19 vaccines are safe and effective during pregnancy, and the protective benefits they offer both the mother and fetus/infant outweigh any known or potential risks. Studies show that getting vaccinated during your pregnancy may help protect your baby against COVID-19, because antibodies are passed to the fetus through umbilical cord blood, and through breast milk if you breastfeed.
The American College of Obstetricians and Gynecologists and the Society for Maternal Fetal Medicine also recommend vaccination for people who are pregnant. If you would like to talk to someone about COVID-19 vaccination during pregnancy, MotherToBaby is a free and confidential service. Experts can answer your questions in English or Spanish via telephone or chat. Your healthcare provider can also provide additional guidance.
Find out more from the CDC about COVID-19 vaccines while pregnant or breastfeeding.

UPDATED OCT. 1: Can people with a history of allergic reactions get a COVID-19 vaccine?

The CDC recommends that people with histories of severe allergic reactions not related to either vaccines or injectable medications get a COVID-19 vaccine. Examples of allergies not related to vaccines or injectable medications include allergies to pets, latex, foods, venom, or things in the environment. People with histories of allergies to medications taken by mouth, or who have family members with severe allergic reactions may also be vaccinated.
Anyone allergic to an ingredient in the COVID-19 vaccines (including PEG or polysorbate) should talk to their health care provider before being vaccinated. Here is a list of the ingredients in the vaccines. Anyone having an allergic reaction to a previous COVID-19 shot should also check with their health care provider before getting another.
Learn more about COVID-19 vaccines for people with allergies.

UPDATED OCT. 27: Should people with weakened immune systems get a COVID-19 vaccine?

Yes, they should. People with moderately to severely weakened immune systems (immunocompromised) may be more likely to get severely ill or to be sick for a longer time if they get COVID-19. Certain medicines, medical conditions, or treatments for medical conditions may cause someone to become immunocompromised. These may include cancer treatments, organ transplants, advanced or untreated HIV, primary immunodeficiency diseases, and immune-suppressing medicines.
Immunocompromised people may build a much smaller amount of protection from the vaccines than someone with a normal immune system would. To help get them closer to a normal level of protection, the CDC recommends that immunocompromised people 18 and older who got the Pfizer or Moderna mRNA vaccines get a third vaccine dose of Pfizer or Moderna at least 28 days after their second dose. They also have the option to receive a single booster dose with any of the available vaccines at least 6 months after completing their third dose. This means that some immunocompromised individuals receiving the mRNA vaccines may receive a total of four vaccine doses.
Yes, they should. People with moderately to severely weakened immune systems (immunocompromised) may be more likely to get severely ill or to be sick for a longer time if they get COVID-19. Certain medicines, medical conditions, or treatments for medical conditions may cause someone to become immunocompromised. These may include cancer treatments, organ transplants, advanced or untreated HIV, primary immunodeficiency diseases, and immune-suppressing medicines.
Immunocompromised people may build a much smaller amount of protection from the vaccines than someone with a normal immune system would. To help get them closer to a normal level of protection, the CDC recommends that immunocompromised people 18 and older who got the Pfizer or Moderna mRNA vaccines get a third vaccine dose of Pfizer or Moderna at least 28 days after their second dose. They also have the option to receive a single booster dose with any of the available vaccines at least 6 months after completing their third dose. This means that some immunocompromised individuals receiving the mRNA vaccines may receive a total of four vaccine doses.
Immunocompromised people 18 and older who received the Johnson & Johnson vaccine should get a single booster vaccine with any of the available vaccines at least 2 months after vaccination.
People are encouraged to speak with their healthcare provider if they have questions about whether they are immunocompromised, or whether they should get a third (or fourth) vaccine or a booster dose. Learn more about COVID-19 vaccines for moderately to severely immunocompromised people, and the guidelines for booster doses for these groups.

UPDATED OCT. 19: Do the COVID-19 vaccines cause infertility?

There is currently no evidence showing that the COVID-19 vaccines cause fertility problems in males or females.
Research studies in women trying to become pregnant found no evidence that anything within the vaccines or the antibodies created following vaccination caused any problems with pregnancy success rates. Women who had the vaccines were able to become pregnant at the same rates as women who did not get vaccinated. Researchers also found no significant changes to men’s sperm characteristics after vaccination. Some people can develop a fever following COVID-19 vaccination, but there is no current evidence this fever after vaccination affected sperm production.  
The COVID-19 vaccines have been the most closely studied vaccines in history. Scientists and health experts continue to monitor them carefully for side effects and report new information and discoveries as they become available. Learn more about COVID-19 Vaccines for People Who Would Like to Have a Baby.

Vaccine Variants

UPDATED AUG. 17: Will the vaccines work against the known COVID-19 variants?

Yes, the FDA-authorized vaccines do protect against the known variants, including Delta. They are effective at keeping people from getting sick, having to be hospitalized, and dying from the virus. Because evidence shows some fully vaccinated people may still be able to spread the Delta variant to others even if they do not have symptoms, the Pima County Health Department strongly recommends that everyone 5 years and older wear a mask indoors in public regardless of vaccination status. Read the latest Public Health Advisory for more on masking and prevention measures.
Health experts do not know how effective the vaccines will be against new variants that may arise. The way to help prevent the development of new variants is for more people to get vaccinated. The CDC offers additional details about the variants and the vaccines.

After Vaccination

Am I still considered "fully vaccinated" if I don't get a booster shot?

Yes. You are considered fully vaccinated 2 weeks after you get a Johnson & Johnson/Janssen vaccine or 2 weeks after you get your second Moderna or Pfizer vaccine.

UPDATED SEPT. 21: What do I do if I lost my vaccine card?

The Pima County Health Department is no longer making replacement vaccine cards. PCHD recommends the following:
  • Contact the state through its online Immunization Record Request Form and return the completed form via email, fax or mail (all listed at the link). For more information, email the Arizona Immunization Program Office at or call 602-364-3630.
  • You can also create an online portal at, which partners with the Arizona Department of Health Services to allow you to review your immunization history, get reminders for future immunizations, and print your own official records.

UPDATED SEPT. 3: I am vaccinated, but how do I protect unvaccinated family members, and what activities can we do?

Being vaccinated against COVID-19 is an important first step to protect yourself and your loved ones including children too young to be vaccinated. Getting your family members aged 12 years and older vaccinated will help reduce the risks of them catching or spreading the virus to others. To protect against the very contagious Delta variant, the CDC recommends everybody aged 2 years and older, including fully vaccinated family members, wear a mask in indoor public places. Wearing a mask indoors in public is especially important for unvaccinated family members, or anyone who has somebody in their household with a weakened immune system.
When choosing safer activities for your vaccinated and unvaccinated family members, remember that outdoor activities are safer than indoor ones. If you have to be indoors, choose well-ventilated locations and avoid crowds. Try to avoid activities that make it hard to stay 6 feet apart from people not in your household. Everyone 2 years and older should wear a mask in indoor public areas, according to the CDC. If your unvaccinated child is younger than 2 years or they are unable to wear a mask, limit visits with people who are unvaccinated (or whose vaccination status you are unsure about), and keep your child distanced from other people in public. Learn other ways to protect yourself and others from COVID-19. 
The CDC offers more tips for how Families with Vaccinated and Unvaccinated Members can help keep each other healthy and participate in safer activities, and updated advice for people who have been fully vaccinated.

UPDATED OCT. 1: Is it possible to get COVID-19 after being fully vaccinated?

Yes, it is possible. No vaccine is 100% effective at preventing infection, so there will always be a small number of people who will still get the virus they were vaccinated against. When this happens, it is known as a “vaccine breakthrough infection.” The COVID-19 vaccines are very effective at preventing infection, serious illness and death, and most of the people who get COVID-19 are unvaccinated.
When vaccinated people do get COVID-19, they are less likely to have severe symptoms (if they develop symptoms). Vaccinated people are 8 times less likely to be infected and 25 times less likely to be hospitalized or die than unvaccinated people, according to the CDC. Because vaccinated people who get COVID-19 can still spread the virus to others, and because of the increased contagiousness of the Delta variant, the Pima County Public Health Department’s latest COVID-19 Public Health Advisory strongly recommends that people wear a mask in schools and when in indoor public places, whether they have been vaccinated or not.
Some people with weakened immune systems (immunocompromised) may still not develop the full protection from the vaccine, so they should ask their health care provider if they should continue to mask and take full precautions even after getting vaccinated.

Find out more from the CDC about the possibility of COVID-19 after vaccination.

General Questions

UPDATED AUGUST 27: Why shouldn't I use Ivermectin for COVID-19?

Ivermectin can NOT treat or prevent COVID-19, or any other viruses. Ivermectin is a medication used to get rid of certain parasites (such as worms) in animals, and some rare conditions in people, but it does not treat viruses. This medication is typically sold in high doses for animals like cows and horses that weigh over a ton. Such high doses can be highly toxic in people. Other ingredients in the medication can be safe for animals, but toxic for people.

Ivermectin is NOT approved for preventing or treating COVID-19, and there is no evidence that it is safe to do so. Taking a drug for an unapproved use can be very dangerous. Hospitals and poison control centers are reporting increasing cases of people suffering nausea, vomiting, balance problems, seizures, and coma.

The FDA has more information on why you should not use ivermectin to treat or prevent COVID-19.

What does the vaccine cost?

The vaccine is free for everybody, regardless of insurance status. For those that have insurance, a small administration fee may be billed.

Is there a wait time for receiving a COVID-19 vaccine or a booster after having had COVID-19?

People who have had a COVID-19 infection should wait to be vaccinated or to get a booster dose until they have recovered from the acute illness (if they had symptoms) and they have met the guidelines for ending isolation.

UPDATED MAY 26: I need transportation to my vaccine, where can I get a ride?

Don’t let a lack of transportation keep you from getting vaccinated! Multiple options exist for those needing a ride to and from their COVID-19 vaccine site.

Rideshare service Uber offers free rides to and from all of the vaccine site locations listed on the Pima County Vaccine Registration page. Call Uber’s Vaccine Line at 1 (855) 632-0557 to be connected with an operator in English or Spanish. Operators are familiar with the Pima County vaccine locations/dates/times, and rides can be requested in real time or scheduled in advance.

The National Council on Aging (NCOA) and rideshare service Lyft have partnered to offer older adults roundtrip rides to and from each dose of their vaccine. Users need to download the Lyft app onto their phone and use a vaccination ride code. Each ride code covers up to $50 ($25 to the vaccine site, and $25 back home). There are no location restrictions, and the ride codes are valid through December 31, 2021. The NCOA has more information and step-by-step instructions for downloading and creating a Lyft account and using the ride codes. AHCCCS Medicaid recipients may also be able to get free non-emergency transportation to and from their vaccination site. Members should contact their health plan to find out more.

UPDATED SEPT. 7: If I just received another vaccine, do I have to wait to get the COVID-19 vaccine?

No, you do not have to wait. COVID-19 vaccines can now be given along with your other vaccines. This means you can get your flu shot or other needed vaccines at the same time as your COVID-19 vaccine. The CDC has more details about the co-administration of COVID-19 vaccines with other vaccines.

UPDATED AUG. 23: If I was treated with monoclonal antibody therapy for COVID-19, should I get vaccinated?

Yes, although you should wait to get a COVID-19 vaccine for 90 days after your monoclonal antibody treatment. The CDC recommends this waiting period to avoid any possible interference between the antibody therapy and your body’s immune response to the vaccine.
The recommendation to wait 90 days also applies if you receive monoclonal antibody therapy between doses of the mRNA vaccines.

The CDC offers additional details on their website.

UPDATED AUG. 10: Once I’m vaccinated, do I still need to worry about infecting others?

With the previous variants of the virus, there was less concern that those who were vaccinated could spread the virus.
The emergence of the Delta variant has changed this however. New data suggest that fully vaccinated people who experience a breakthrough infection can spread this variant to others. This is because this variant creates a greater amount of virus in the body of an infected person even more quickly. Health experts are still trying to understand whether fully vaccinated people who have a breakthrough infection but who do not have symptoms are able to infect other people. Learn more about what we know about the Delta variant.
Because fully vaccinated people who get a rare breakthrough infection with symptoms (and maybe even those without) can spread the virus to others, the CDC changed its guidance to recommend that everyone wear masks indoors in public places. The Pima County Health Department strongly recommends all Pima County residents age 5 and older (including fully vaccinated individuals) wear masks in public indoor settings if six feet of physical distancing can’t be maintained.  The Health Department also strongly recommends all teachers, staff, students, and visitors to K-12 schools wear masks indoors at all times, regardless of vaccination status. Teachers, school administrators and staff should follow CDC's school guidance. Read the Health Department’s latest Public Health Advisory.
Getting vaccinated is of even more importance now with the Delta variant, because it protects against the severe illness and death seen with this variant.

If I have an active case of COVID, can the vaccine be used as a treatment?

Individuals with an active case of COVID-19 need to wait until recovery before receiving the vaccine, according to Pima County Health Director Dr. Theresa Cullen.

UPDATED DEC. 22: Can my employer require me to get vaccinated?

Yes. According to the Equal Employment Opportunity Commission (EEOC), employers may require employees to take the COVID-19 vaccine, subject to certain legally protected exceptions for disability and sincerely held religious beliefs.

Employers may ask employees to show proof of receipt of a COVID-19 vaccination.

If an employer requires the vaccine, or contracts with a vendor to provide the vaccine, then the pre-vaccination medical screening questions are subject to ADA standards for disability-related inquiries (i.e., must be job-related and consistent with business necessity); if voluntary, or if the employee receives the vaccine from a third party that does not have a contract with the employer, then these ADA restrictions do not apply.

UPDATED AUG. 19: Should I get the flu vaccine?

Yes! Influenza (flu) can cause serious illness, and the flu vaccine is a safe and effective way to prevent it. You can help avoid overwhelming our hospitals and providers’ offices by being vaccinated. September and October are the months most providers recommend you get your flu vaccine, so that your body has time to build up protection. Even if you just had your COVID-19 vaccine, you can still get your flu shot, since the COVID-19 vaccine may be given with other immunizations.

UPDATED MAY 26: How effective are the vaccines in people over 65?

The vaccines are extremely effective in older adults. People 65 and older fully vaccinated with the Pfizer and Moderna vaccines are 94% less likely to be hospitalized with COVID-19. During the Johnson & Johnson clinical trials, no-one who received the vaccine had to be hospitalized with COVID-19. Older adults also experienced fewer vaccine side effects.

UPDATED MAY 26: How long does vaccine immunity last?

WCurrent studies show people who were vaccinated develop a very strong immunity to COVID-19. Information on the length of immunity is limited to the amount of time the vaccines have been studied. Ongoing clinical trials by vaccine manufacturers indicate that antibodies may persist for a long, but currently unspecified time. Some vaccine experts speculate that protection may last for a year or more. Data will continue to emerge as scientists monitor those who were vaccinated for signs of declining immunity. Also, antibodies are not the only component of immunity.

Other parts of the immune system (B and T cells for example) may last longer than antibodies do, and health experts will study how these lines of defense may also affect the length of vaccine immunity.

UPDATED AUGUST 27: How many vaccines have been approved?

There are 3 COVID-19 vaccines currently used in the United States. Pfizer, Moderna, and Johnson & Johnson were granted Emergency Use Authorization (EUA) from the FDA. Recently, the Pfizer vaccine received full FDA approval for use in those 16 years and over.

The first two vaccines are mRNA vaccines – what does that mean?

mRNA vaccines take advantage of the process that cells use to make proteins in order to trigger an immune response and build immunity to COVID-19. In contrast, most vaccines use weakened or inactivated versions or components of the disease-causing pathogen to stimulate the body’s immune response to create antibodies.

mRNA vaccines have strands of genetic material called mRNA inside a special coating. That coating protects the mRNA from enzymes in the body that would otherwise break it down. It also helps the mRNA enter the muscle cells near the vaccination site.

mRNA can most easily be described as instructions for the cell on how to make a piece of the “spike protein” that is unique to the virus that causes COVID-19. Since only part of the protein is made, it does not do any harm to the person vaccinated but provides immunity.

After the piece of the spike protein is made, the cell breaks down the mRNA strand and disposes of them using enzymes in the cell. It is important to note that the mRNA strand never enters the cell’s nucleus or affects genetic material. mRNA vaccines do not alter or modify someone’s genetic makeup.

Once displayed on the cell surface, the protein or antigen causes the immune system to begin producing antibodies and activating T-cells to fight off what it thinks is an infection. These antibodies are specific to the COVID-19 virus, which means the immune system is primed to protect against future infection.

Keep track of the progress of all the vaccines undergoing testing at the New York Times' Coronavius Vaccine Tracker.

UPDATED DEC. 21: How can I protect myself from scams?

While the newly-approved COVID-19 vaccine offers hope of controlling the pandemic, scammers see the vaccine as an opportunity to steal from hopeful consumers.

The FBI and the Department of Health and Human Services’ (HHS) Office of Inspector General have been issuing alerts about the increase in coronavirus fraud. Scammers aren’t just using email or telemarketing calls. They are also coming at people via messages on social media platforms, and they’re even performing door-to-door visits, HHS says.

Vaccine scam flyer

Do I need to delay my mammogram after getting the vaccine?

The COVID-19 vaccines often elicit a very prominent immune response which can result in tender, swollen lymph nodes under the arm. Called “axillary adenopathy,” it signals inflammation, which is the body’s normal response to vaccination. Recently, it has been increasingly confused with cancer on regular screening mammograms, MRIs or ultrasound exams when a patient has recently had their COVID-19 vaccine.

False positives due to adenopathy from the vaccines have resulted in undue alarm and sometimes additional unnecessary testing. In response, the Society of Breast Imaging published guidelines for scheduling mammograms in a way to help avoid this. They recommend that if possible, and when it does not unduly delay care, patients and their providers consider scheduling breast screening exams before receipt of the first dose of a COVID-19 vaccine, or wait 4-6 weeks following the second dose of vaccine (if using a two-shot series) before being screened.

Anyone experiencing a suspicious lump is still encouraged to consult with their healthcare provider.

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