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What To Know About COVID-19 Vaccines

Sep 22, 2022
By Spencer Blackman, MD

Updated September 22, 2022.

Clinical Editors: Megan Dodson, PA-C, Spencer Blackman, MD, Will Kimbrough, MD

One Medical supports vaccination as an important measure to reduce the spread and harm from COVID-19, and we want you to have the most updated vaccine information.

Here are our answers to some of your most commonly asked questions:

How does the COVID-19 vaccine work?

The Pfizer/BioNTech and Moderna COVID-19 vaccines, approved in December 2020, use messenger RNA (mRNA) which delivers a small genetic “message” that causes your own cells to make a protein that resembles the spike on the outer shell of the tiny COVID-19 virus. Your immune system then recognizes this protein as foreign, and produces specific antibodies and specialized immune cells (T-lymphocytes and B-lymphocytes) that quickly spring into action if the virus itself shows up in the future.

The Johnson & Johnson (vaccine works in a similar way, but instead uses a harmless cold virus to deliver the information that the immune system uses to create protection.

The Novavax vaccine uses proteins from the COVID-19 virus to create an immune response. This is similar to how many widely used vaccines work, such as vaccines for human papillomavirus, hepatitis B and shingles.

What are the benefits of the COVID-19 vaccine?

COVID-19 vaccines have been shown to be highly effective in preventing severe illness and death from COVID-19. We’ve also learned that this protection fades over time, especially for people who are older or who have health conditions that affect their immune system. The vaccines also substantially reduce the risk of getting any level of infection from COVID-19 for a few weeks after receiving them.

How are the vaccines administered?

The vaccines are administered the same way as the flu shot, injected into the muscle of the upper arm.

What are the common side effects?

Common side effects may include pain around the area of the injection, feeling tired, headache, muscle aches, and less commonly, fever. So far, severe side effects have been reported to be very rare with these current COVID-19 vaccines. As with all vaccines, there have been rare reports of serious allergic reactions to the vaccine. If you've ever had a severe allergic reaction or anaphylaxis to any ingredient in either of the COVID-19 vaccines, it is not considered safe to get that specific vaccine. If you have a history of severe allergic reactions, please speak to your healthcare provider for guidance before being vaccinated.

In April 2021, the FDA paused J&J vaccination in the U.S. because of 6 cases of rare brain blood clots associated with low platelets in females
under the age of 50. The experiment panel met again a week later and decided it was safe to continue the J&J vaccine campaign for individuals who cannot receive the mRNA vaccines, but the mRNA vaccines are preferred in order to avoid this risk.

Inflammation of the heart muscle (myocarditis) is another possible side effect that is associated with the mRNA vaccines (Pfizer and Moderna). Adolescent and young adult males have experienced higher rates of myocarditis compared to other groups, but overall, it's not common. Please check out the CDC site about myocarditis and talk to your healthcare provider for more information.

How much does the vaccine cost?

According to the CDC, “COVID-19 vaccines are paid for with taxpayer dollars and are given free of charge to all people living in the United States, regardless of health insurance or immigration status.”

If multiple types of COVID-19 vaccines are available, will I have a choice about which one I receive?

The CDC has approved a “mix and match” strategy, meaning that individuals who are eligible for a booster shot can receive a different brand for their booster than they received for their primary series. Pfizer or Moderna are the preferred brands for the booster, as the FDA limited the use of the J&J vaccine due to an increased risk of a blood clotting condition. However, if you are unable to receive Pfizer or Moderna, you will still be able to receive the J&J vaccine.

For the Pfizer/BioNTech or Moderna vaccine, when can I get my second dose? What about booster doses?

After the first dose of the Pfizer/BioNTech vaccine, a second dose can be given as soon as 21 days and as far out as 8 weeks. For the Moderna vaccine, a 4-8 week interval is recommended.

The CDC recommends a bivalent booster dose 2 months after your initial vaccine series or your last booster dose to boost immunity and to better protect against the currently circulating omicron strains. Learn more about booster vaccines here.

Can I receive the Pfizer/BioNTech or Moderna vaccine with other vaccines?

Yes. All authorized or approved COVID-19 vaccines can be given alongside other approved immunizations (like flu or pneumonia shots).

Adolescent or young adult males may consider waiting 4 weeks after JYNNEOS™ vaccination before getting an mRNA COVID-19 vaccine to reduce the risk of myocarditis (inflammation of the heart). However, it’s not necessary to delay monkeypox vaccination should you need it after your COVID-19 booster. If you’re not sure about the timing, talk with your healthcare provider.

Once I’m fully vaccinated, will I still need to get tested for COVID-19?

Yes. While the vaccines are highly effective at preventing complications from COVID-19, they only modestly reduce your risk of infection. If you have symptoms consistent with COVID-19, we recommend getting tested to determine if your symptoms are being caused by COVID-19. Even if you test negative, consider avoiding crowds or people who are high-risk for COVID-19 complications until you’re feeling better.

I’ve had COVID-19 already. Should I still get a vaccine?

Yes. Even if you’ve had a COVID-19 infection, it's still possible to get infected again.Vaccination will help prevent complications in the event of future infections.

People with a current COVID-19 infection should defer the vaccine until they have recovered from acute illness and can discontinue isolation. They may also consider waiting 3 months post-infection to get the vaccine.

How confident can we be that the vaccines used in the United States are safe?

While the specific vaccines are new, the ways in which they create an immune response have either been in testing or in widespread use for many years. The idea of a “never-before-used” genetic vaccine may seem intimidating, but the underlying technology has been proven safe on thousands of volunteers. Only the specific COVID-19 genetic message is truly new. The safety standards of the FDA remain stringent and the safety of the vaccines will continue to be closely monitored. At One Medical, our own senior clinical advisors regularly review the published safety data carefully, and we only offer vaccines when we strongly believe the benefits unequivocally outweigh any risks. We agree with the FDA that the Moderna, Pfizer, Johnson & Johnson, and Novavax vaccines safely deliver very high protection from serious disease from this virus.

If I get the COVID-19 vaccine will it affect COVID-19 test results?

No. Per the CDC, the COVID-19 vaccine cannot cause you to falsely test positive or negative on PCR or antigen viral tests, which are used to see if you have a current infection.

What if I’m pregnant, breastfeeding, or have a compromised immune system?

COVID-19 vaccination is recommended for people who are pregnant, breastfeeding, trying to get pregnant, or might become pregnant in the future. Pregnant and recently pregnant people are more likely to get severely ill with COVID-19 compared with non-pregnant people. Getting a COVID-19 vaccine can protect you from severe illness from COVID-19. If you have questions, you should talk to your provider to make an informed decision for your unique situation. More information about pregnancy and the vaccine is available here.

Can I vaccinate my child?

If your child is 6 months or older, they're eligible to receive the Pfizer/BioNTech or Moderna COVID-19 vaccine. The CDC now considers it safe to receive the COVID-19 vaccine at the same time as other recommended vaccines. For more information on COVID-19 vaccines for children, see here.

Will I need a booster shot of the COVID-19 vaccine?

The CDC is now recommending a booster, or third dose of the Pfizer/BioNTech, Moderna, and a second dose of the Johnson & Johnson (J&J) COVID-19 vaccine. Those who are 5 years and older who received a Pfizer/BioNTech are eligible for a booster shot five months or more after their second dose. Booster shots are also recommended for anyone 18 years and older who either received the Moderna vaccine at least six months ago, or received the J&J vaccine two or more months ago.

An additional second booster has also been authorized by the FDA for people 12 years and older and those who are immunocompromised who received their first booster four or more months ago. Guidance from the CDC on who is recommended to get a second booster vaccine is still pending, but expected to be issued very soon. For more on COVID-19 booster vaccines, read here.

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Spencer Blackman, MD, One Medical Provider

Spencer practices relationship-centered primary care, blending a traditional sensibility with up-to-date clinical knowledge and a strong focus on disease prevention. He enjoys getting to know his patients well, educating and empowering them to participate in health care decisions. Spencer completed his residency training at UCSF and practiced primary care, urgent care, sports medicine and adolescent medicine throughout the Bay Area before joining One Medical Group. He is certified with the American Board of Family Medicine. Spencer is a One Medical Group provider.

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The One Medical blog is published by One Medical, a national, modern primary care practice pairing 24/7 virtual care services with inviting and convenient in-person care at over 100 locations across the U.S. One Medical is on a mission to transform health care for all through a human-centered, technology-powered approach to caring for people at every stage of life.

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