COVID-19 Vaccines FAQ

How good are the vaccines at preventing COVID?

Really good. 

These vaccines are very good against preventing severe COVID, especially against the original variants. However, no vaccine is 100% effective, and some behaviors should still be avoided until we are able to vaccinate a large enough percentage of our population. It’s really important that we stop the spread, not just in the US, but around the world, so that new variants don’t emerge. Until that happens, we may need booster shots every year. 

Do I need to pay for the vaccine?

The federal government is providing the vaccine free of charge to all people living in the United States, regardless of their immigration or health insurance status.

COVID-19 vaccination providers cannot:

  • Charge you for the vaccine
  • Charge you directly for any administration fees, copays, or coinsurance
  • Deny vaccination to anyone who does not have health insurance coverage, is underinsured, or is out of network
  • Charge an office visit or other fee to the recipient if the only service provided is a COVID-19 vaccination
  • Require additional services in order for a person to receive a COVID-19 vaccine; however, additional healthcare services can be provided at the same time and billed as appropriate

-> if you have insurance, they can ask you for it so that they can bill the insurance for the cost of administering the vaccine. But if you don’t have insurance, they will just bill the government and you can still get the vaccine. They also cannot bill you for anything your insurance refuses to cover (no “balance billing”). There will not be any cost to you for getting vaccinated against COVID-19.

Is a particular COVID vaccine the best for me?

If you are age 12-17, you can only get the Pfizer vaccine for now. All three vaccines approved in the US are all equally effective at preventing hospitalization and death. This 7-minute Vox video is a must watch that explains it well, and why efficacy data from vaccine trials doesn’t tell the whole story.

Real-world data is coming in slowly, and really the only conclusion is that as more variants emerge, we will likely all need boosters. But the sooner we all get vaccinated with something, the sooner we can shut down the spread of variants and eliminate opportunities for new variants to develop — which could evade our vaccines.

What’s happening with the Johnson & Johnson/Janssen vaccine?

The Johnson & Johnson/Janssen vaccine is once again available for use — but now it has additional information about a potential side effect.  Because we are monitoring what happens after vaccination so carefully, regulators were able to identify a very rare side effect — a specific type of blood clot. So they recommended a pause in administration of the vaccine out of an abundance of caution to allow an investigation. That investigation has now concluded, and people can once again get the one-dose vaccine. It now will be accompanied by warnings about the small risk of blood clots, and information about how to treat them if they occur.  People who have received the J&J/Janssen COVID-19 vaccine within the past three weeks who develop severe headache, abdominal pain, leg pain, or shortness of breath should seek medical care right away, and should inform their health care providers that they recently received the J&J vaccine. Many people prefer the J&J vaccine because it is only one dose, and it is certainly easier to use for hard-to-reach populations since it is not as fragile as the mRNA vaccines from Moderna and Pfizer.  

More resources here:

Can I get a COVID vaccine if I’m undocumented?

Yes!  Please!  We have to vaccinate everyone possible in order to protect everyone.  The virus doesn’t discriminate based on race or nationality — so the COVID vaccine is being made available to everyone who meets the age requirements free of charge.  

Is one of the COVID vaccines better for certain ethnic or racial groups? 

The short answer is that we really don’t know. The data from the clinical trials was very limited, as explained in the links, and real world data is coming in as we talk. What we do know is that all three vaccines had similar efficacy at stopping all disease and effectiveness at preventing serious illness and hospitalization. 

There were very few Asians in the trials. Government and companies need to do better outreach and trust-building to Asian communities (and all the different subgroups that fall under the broad category of “Asian”). This article explains the breakdown and problems with over-interpreting the trial data for ethnicities and racial groups.

Which vaccine has the mildest side effects?

No study has yet been released comparing all three vaccines, but there is a new study which did compare Moderna and Pfizer/BioNTech, and Moderna had slightly more people reporting reactogenicity (feeling symptoms associated with an immune response to the vaccine). (Reactogenicity Following Receipt of mRNA-Based COVID-19 Vaccines | JAMA Network)

If you do have a reaction, report it at

Should my child get a COVID vaccine?

Yes, children ages 12 and up can get the vaccine now! Currently, only Pfizer has been approved for ages 12 through 17, but trials in younger children are happening right now. Vaccinating children and teens is an essential part of protecting them — and their communities — from the pandemic. And when a vaccine is available to them, vaccinating younger children will be important too.

Are COVID vaccines safe for pregnant people?

Yes! The CDC is now recommending vaccination for pregnant people.

We know COVID itself is very dangerous to pregnant people and the babies they carry.

So far we only have one study about the vaccines and pregnancy. The preliminary results are based on reports from over 35,000 U.S. women who received either the Moderna or Pfizer shots while pregnant. Their rates of miscarriage, premature births and other complications were about the same as what pregnant people experienced before the pandemic (and thus never got the COVID vaccines)

Can I get the vaccine if I’m nursing or pumping milk for my baby?

Clinical trials for the COVID-19 vaccines currently authorized for use under an Emergency Use Authorization in the United States did not include people who are breastfeeding. The COVID-19 vaccines authorized now are non-replicating vaccines, which means they are able to create an immune response but do not reproduce inside host cells. Because non-replicating vaccines pose no risk for lactating people or their infants, COVID-19 vaccines are also thought to not be a risk to the breastfeeding infant. Therefore, lactating people may choose to be vaccinated. There may be benefits to both the adult and child.

COVID antibodies have been found in the breast milk of people who were vaccinated while lactating, and in the cord blood of infants born to people who were vaccinated while pregnant.

People who get vaccinated against COVID while pregnant likely pass antibodies to their newborns. One study shows that antibodies were found in the cord blood of newborns whose gestating parent had been vaccinated while pregnant. We don’t yet know how protective those antibodies are.

A study in Israel showed that COVID antibodies appeared in breastmilk six weeks after a lactating parent received vaccination. We don’t yet know if those antibodies provide significant protection to the baby, and it probably wouldn’t provide lasting immunity.

Should I get vaccinated if I’m trying to become pregnant?  

If you are trying to become pregnant now or want to get pregnant in the future, you may receive a COVID-19 vaccine when one is available to you.

There is currently no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems. CDC does not recommend routine pregnancy testing before COVID-19 vaccination. If you are trying to become pregnant, you do not need to avoid pregnancy after receiving a COVID-19 vaccine. Like all vaccines, scientists are studying COVID-19 vaccines carefully for side effects now and will report findings as they become available.

Resources on fertility:

There is no evidence the vaccines affect fertility.

Resources on irregular periods:

Can I get vaccinated if I have a complication or autoimmune condition?  

In general, COVID is more dangerous than the vaccines, but your doctor knows your condition best. There may not be specific data about your particular medical history from the trials, so you should definitely speak with your doctors.  More resources can be found here.

How good are the vaccines against the new variants?

Pretty good. Definitely worth having the protection of the vaccine. This New York Times article does a good job answering questions about the variants.

How long will I have protection from COVID once I’m vaccinated?

Early results show that the protection lasts at least six months, at least for the Pfizer vaccine. It could be longer, but we just don’t know yet. We will likely need boosters to extend protection and cover new variants that emerge while the virus continues to circulate around the world. And we need to wait for data to be studied about the other vaccines.

Can I take or do anything to prevent side effects of vaccination?

Be well hydrated and rested ahead of time, but don’t pre-dose with a pain reliever. Afterwards, if you don’t feel well, you can treat symptoms as they arise with tylenol or ibuprofen. If symptoms are severe or persist past 72 hours, call your doctor. You might want to try to have a light day after your vaccine, if possible. Tips for minimizing symptoms and maximizing effectiveness. If you get the Johnson & Johnson vaccine, be sure to contact your doctor immediately if you develop severe headache, abdominal pain, leg pain, or shortness of breath, and tell your doctor that you received the Johnson & Johnson vaccine so that you can be promptly examined and treated properly if needed.

What things can I do safely once I’ve gotten vaccinated?

Many things! The European Union just announced that fully vaccinated people are even welcome to visit Europe this summer! Closer to home, vaccinated people can socialize in small groups indoors without masks.  Vaccinated grandparents can hug their unvaccinated grandchildren. We still need to wear masks when indoors with groups of unvaccinated people, like at the grocery store, and in some other higher-risk situations. For more details, read guidance from these resources:

Should I get vaccinated if I’ve already gotten COVID?

Yes, you should be vaccinated even if you already had COVID-19. We do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible—although rare—that you could be infected with the virus that causes COVID-19 again.  If you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.

Why should I get vaccinated if I am at low risk of getting sick from COVID? 

Even if you are not at high risk of getting severe COVID-19 or dying, you could either be the person in whom the virus mutates to become more virulent or you could pass it on to someone who is vulnerable. We have to create a wall of immunity to stop the virus from circulating or mutating, and getting everyone vaccinated quickly is the safest way to do it.

Why do I need to continue to wear a mask after getting vaccinated? 

Because there are still so many people who are unvaccinated, and because no vaccine is 100% effective, there’s still a chance you could get COVID yourself, and even if you don’t get very sick because you’ve been vaccinated, you could spread it to someone else who doesn’t yet have the protection of a vaccine and they could wind up seriously ill. We may be able to relax more as we approach herd immunity in our communities, and even more once the virus stops circulating around the world, because then new variants will be less likely to emerge that can evade the vaccine protection.

What is herd immunity/community immunity, and how many of us need to be vaccinated before we reach that level of protection?

Here immunity is how you stop a contagious disease from circulating.  When enough people in a community are immune, either because they had the disease, or because they were vaccinated, the disease has no one to infect, and it ceases to spread.  Because the virus that causes COVID-19 is so contagious, we need a high percentage of people to be immune to stop it from circulating. Researchers are still discussing exactly how many people need to be immune to achieve herd immunity. Because immunity from the vaccine lasts longer than from the disease, and because being vaccinated is far less risky than getting sick, it’s much better to achieve herd immunity through vaccination.

Are there long-term side effects of the vaccines?

Long-term side-effects is something people often wonder about, especially with new vaccines. Almost all adverse reactions to vaccines happen within the first 48 hours or first 6-8 weeks after vaccination. That’s why regulatory approvals aren’t given until a trial has at least 8 weeks of post-vaccination data, and the benefit of the vaccine can be weighed against whatever adverse reactions happen. Here are resources about vaccine development and monitoring for side effects. 

Are the vaccines going to be required for work or school? 

So far, the vaccines have only been approved for emergency use. Some schools, like the University of California and California state school systems, are planning to require vaccines for all faculty, staff, and students once the vaccines are fully approved. As yet, those plans haven’t been finalized, and no vaccine has even been submitted for full approval by federal regulators, but we hope that will happen soon. It’s possible that some health care providers or emergency responders may require vaccination for people who work directly with patients and the public. 

What’s in the vaccines?

Each vaccine has a slightly different component list.  A good explanation is here:

To learn more about the ingredients in authorized COVID-19 vaccines, see:

Is there fetal tissue in the vaccines?

No.  There is no fetal tissue. Various stages of vaccine development and testing did utilize fetal cell lines, but there is no tissue in the vaccines.   No fetuses were harmed in the development or production of the vaccine. However, if you refuse the vaccine and inadvertently transmit the virus to a pregnant woman, you could harm that mother and her baby.  More information about that is here:

And here is a video explaining the science.

How were the vaccines developed and approved so quickly? 

No safety measures or efficacy tests were skipped or short-changed in developing the vaccines. A number of things were done to speed the process, and scientists were able to leverage prior research to help. 

First, Phase 1 testing, which involves just a few people and looks at how safe the vaccine is, was combined with Phase 2, which looks at safety and efficacy in more people with more diverse backgrounds and underlying conditions.  Phase 1 data was collected by allowing researchers to look at a subset of the Phase 2 participants. Combining Phase 1 and Phase 2 is done when companies are willing and able to enroll more participants early.  A lot of people were willing to participate in the trials — which really helped bring them to the public a lot faster.

Second, we started manufacturing the vaccines in large quantities even before the trials were completed so that we would be ready to roll it out once approved by regulators. Normally, we wouldn’t risk wasting all the funding required for manufacture until approvals were in hand. 

Third, a lot of planning for distribution happened before approval, so that we would be ready to distribute to the entire population — especially communities hit hardest by the virus and most at risk — as soon as approval was granted.

Finally, the science behind both vaccines has been around for a while. The mRNA vaccine technology had been in development for almost a decade.  Developed as essentially a “plug-and-play” vaccine, as soon as the DNA for the virus was known, researchers could follow the instructions they’d already developed to create an mRNA vaccine based on the specific spike protein on the novel coronavirus.  And the adenovirus vaccines developed by Johnson & Johnson/Janssen and AstraZeneca use the same technology used in the Zika virus vaccine.  

Questions and Answers about COVID-19 Vaccines (Children’s Hospital of Philadelphia)

What are good things for me to say to friends and family who are still not confident they should get vaccinated?

We’re glad you asked! Here are some good tips.

Additional resources: