Frequently Asked Questions About COVID-19 Vaccines

This FAQ was updated on August 26, 2021.

Remember to contact your healthcare provider if you have specific questions about COVID-19.

Are the vaccines working?

The three vaccines approved in the United States have shown to be effective at preventing COVID-19, especially severe illness and death. Cases, hospitalizations, and deaths have been increasing once again in the United States due to the highly transmissible Delta variant. The vast majority of the new cases, hospitalizations, and deaths that are occurring right now are in unvaccinated people which means the vaccines are helping to protect those that are vaccinated. The more the virus circulates, the more opportunities it has to mutate, and it is possible the vaccines will not be as effective against a new or existing variant. That is why it is important to get as many people vaccinated as possible now. The best way to prevent new variants from emerging is to prevent the virus from replicating. We need people to be vaccinated and protected to break up the transmission chain, so the virus doesn’t have a chance to replicate.

What is a “breakthrough” case?

“Breakthrough” cases of COVID-19 occur in individuals who have been fully vaccinated. These cases have been rare but are increasing due to the highly transmissible Delta variant. If you are exposed to a large enough dose of the virus, it may have the chance to infect your cells and start replicating. In these cases, the individual may have enough virus in their system to infect others or experience symptoms. This is why it’s important to continue wearing a mask, wash your hands, and practice physical distancing in public places. For more information, check out this explanation of breakthrough cases from the UIHC.

Do I need a booster shot?

The COVID-19 vaccines continue to be highly effective in reducing severe disease, hospitalizations, and deaths. Experts are currently looking at available data to understand how long the vaccines are effective and if they are affected by new variants, like the Delta variant. It is possible that booster shots will be recommended for everyone starting in the fall and only after a certain amount of time has passed since your last vaccination.  Booster shots are currently available for individuals who are moderately to severely immunocompromised.

What vaccines are currently available in the United States?

Three vaccines are currently approved by the FDA for use in the United States. The FDA has granted full approval for the Pfizer-BioNTech (COMIRNATY) COVID-19 vaccine. The FDA has also approved the Moderna and Johnson &Johnson vaccines with Emergency Use Authorizations. The vaccine you receive will depend on what your provider has available. The table below compares the three vaccines in use today. The Pfizer and Moderna vaccines require two separate shots so make sure to schedule your second shot when you receive your first dose. Only one shot is needed for the Johnson & Johnson vaccine.
Company Mechanism Dosage Approved for Ages
Pfizer, Inc. and BioNTech mRNA 2 shots,
21 days apart 12 and older
ModernaTX, Inc. mRNA 2 shots,
28 days apart 18 and older
Johnson & Johnson/ Janssen Viral vector 1 shot 18 and older

When am I considered “fully vaccinated”?

It takes time for your body to build up immunity after receiving the vaccination. You are considered fully vaccinated two weeks after your second shot (if receiving the Pfizer or Moderna vaccines) or two weeks after your first and only shot of the Johnson & Johnson vaccine. Make sure to receive both vaccines if you are getting a two-dose series and talk to your provider about scheduling your second dose within the recommended time frame.

When can I get a vaccination?

Everyone 12 years of age and older is eligible for a COVID-19 vaccine in the United States. Check if you need help finding a vaccine or contact your local pharmacy to check availability.

Where can I get a vaccination?

Many people will be able to get vaccinations through their healthcare providers or local pharmacies. The CDC also lists other resources on their website:
• Visit to find vaccination providers near you. The webpage is available in both English and Spanish.
• If you or someone you know speaks a language other than English or Spanish, and need help finding a vaccine provider or have additional questions, call 1-800-232-00233.
• Check your local pharmacy’s website to see if vaccine appointments are available. To find out which pharmacies are participating in the Federal Retail Pharmacy Program website.

You can contact your state health department for more information on additional vaccination locations in your area.

South Dakota 
North Dakota 

Do I still need to wear a mask and practice physical distancing after my vaccination?

Yes, you need to continue to wear a mask and stay six feet away from others, especially until you are fully vaccinated, which is two weeks after your second dose of the Pfizer or Moderna vaccines, or two weeks after your first and only dose of the Johnson & Johnson vaccine. After you are fully vaccinated, the CDC says you can some resume activities without wearing a mask or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance. Masks are still required when using public transportation (traveling in planes, trains, and buses, etc.). Healthcare settings still require masks as well. However, the CDC recommends continuing to wear a mask and practicing physical distancing in areas with substantial or high rates of community transmission. Substantial transmission is 50-100 new cases per 100,000 people over seven days, or an 8-10% positivity rate. High transmission is over 100 new cases per 100,000 people over seven days, or a 10% or higher positivity rate. Currently, the entire US is experiencing substantial or high rates of transmission, so it is critical to keep wearing a mask, staying six feet away from others, and frequently washing your hands. We need to practice all these different strategies to stop the spread and to protect those who are most vulnerable (e.g., young children, immunocompromised individuals). You can check the transmission rate of your county here.

What if I’m vaccinated but am exposed to someone with COVID-19?

If you have had close contact with someone who has COVID-19, you should get tested 3-5 days after your exposure, even if you don’t have symptoms. You should wear a mask indoors in public for 14 days following exposure or until your test result is negative. You should isolate for 10 days if your test is positive. These CDC recommendations are based on evidence that fully vaccinated people that become infected with the Delta variant can still transmit the virus to others.

What are common side effects from getting a vaccination?

Common side effects include pain or swelling in the arm where you got the shot, as well as fever, chills, headaches, and fatigue. You may not feel well for a day or two, especially after your final shot, but these side effects are normal and mean that your body is responding to the vaccine and working to build protection against the virus.

Call your doctor if pain or redness where you got the shot increases after 24 hours, or if your other side effects do not seem to be going away after a few days.

Can I take over-the-counter (OTC) medications before getting my COVID-19 vaccine to reduce side effects?

No, it is not recommended you take any OTC medicines before vaccination for the purpose of trying to prevent side effects because it is not clear if they will affect the vaccine’s effectiveness. Medications that reduce fevers and inflammation (like acetaminophen and ibuprofen) may affect how your immune system responds to the vaccine if taken before vaccination.
Talk to your doctor about taking over-the-counter medicine, such as ibuprofen, acetaminophen, aspirin, or antihistamines, for any pain and discomfort you may experience after getting vaccinated. You can take these medications to relieve post-vaccination side effects if you have no other medical reasons that prevent you from taking these medications normally. For more information, see the CDC pages on what to expect after vaccination and clinical considerations for vaccines.

Can I get COVID-19 from a vaccination?

No, you cannot get COVID-19 from a vaccination. None of the vaccines contain any live virus so they cannot give you COVID-19.

Will a vaccine cost me anything?

No, the government is providing the vaccine to all people living in the United States for free, regardless of their immigration or health status. Vaccination providers cannot charge you for the vaccine or charge you for an office visit if you are only there to get a vaccine. For more information, check the CDC’s website for vaccination information.

Can I get a COVID-19 vaccine at the same time as another vaccine?

You can get a COVID-19 vaccine and other vaccines at the same visit. You no longer need to wait 14 days between vaccinations. Experience with other vaccines has shown that the way our bodies develop protection, known as an immune response, after getting vaccinated and possible side effects of vaccines are generally the same when given alone or with other vaccines. For more information, see this webpage.