2023-2024 COVID-19 Vaccine Effectiveness, Side Effects, Safety, and More

An MSK employee (seated) receives a COVID-19 vaccination.

Everyone age 6 months and older is eligible to get the 2023-2024 COVID-19 vaccine.

You may have read about a new COVID-19 vaccine (shot) that is available in the U.S. This vaccine targets the variants that are now circulating and are expected to spread in the fall and winter seasons. The Centers for Disease Control and Prevention (CDC) recommend that everyone age 6 months and older get this new shot.

Mini Kamboj

Mini Kamboj

Mini Kamboj, Chief Medical Epidemiologist at MSK, has answers to common questions about the vaccine, its effectiveness, possible side effects, and more.

Who is eligible to get the 2023-2024 COVID-19 vaccine?

Everyone age 6 months and older is eligible to get the 2023-2024 COVID-19 vaccine. If it’s been 2 months since your most recent COVID-19 vaccination or since you were infected with COVID-19, you should get the shot.

If you have cancer, you may have a weakened immune system (called immunocompromised). Protecting yourself from COVID-19, including getting vaccinated, is even more important.

Read more about what to know if you have cancer.

What does it mean that there is a new COVID-19 vaccine? How is it different from the shots I already got?

The COVID-19 virus continues to change, and vaccines must keep pace. The technology behind the COVID-19 vaccines allows for quick changes to the vaccine to match the virus’s circulating strains so that the vaccines provide the best possible immunity.

The newly approved 2023-2024 COVID-19 vaccine replaces the previously available bivalent vaccine. It targets the currently spreading XBB variant and related variants.

How effective is the 2023-2024 COVID-19 vaccine?

Vaccination helps prevent severe COVID-19 and the risk of emergency room visits or hospitalization due to COVID-19. Studies also show that vaccination reduces the chances that you will develop long-term effects from COVID-19 infection. While vaccines may not always prevent catching COVID-19, they will protect you from getting severely ill.

Are COVID-19 vaccines safe?

Yes, the 2023-2024 COVID-19 vaccine is safe. It works in the same way as the original COVID-19 vaccines and all booster shots. They are made using the same process.

For all versions of COVID-19 vaccines, serious side effects have been very rare, and they are treatable. Read more about side effects and rare, serious health problems that have been reported after COVID-19 vaccination.

The U.S. Food and Drug Administration (FDA), CDC, and the companies that make the vaccines have been rigorously monitoring safety data for all vaccines. That crucial work is continuing with this new version of the vaccine.

Can children get the COVID-19 vaccine?

Yes. The 2023-2024 COVID-19 vaccine is safe and recommended for children starting at age 6 months.

Read about what it means for children to be up to date on their COVID-19 vaccines.

Can I get the COVID-19 vaccine if I am trying to get pregnant or when I am pregnant or breastfeeding?

Yes. The 2023-2024 COVID-19 vaccine is safe and recommended for people who are trying to get pregnant and people who are pregnant or are breastfeeding.

Can I get the COVID-19 vaccine if I have cancer or if I have been treated for cancer?

Yes. The 2023-2024 COVID-19 vaccine is safe and recommended for people who have cancer now or who have been treated for cancer. You may have a weakened immune system (called immunocompromised). This can put you at higher risk for severe COVID-19. Protecting yourself from COVID-19, including getting vaccinated, is very important.

Read more about what to know if you have cancer.

What are the possible side effects of the COVID-19 vaccine?

You could experience soreness at the injection site, fatigue, headache, body aches, and fever. These symptoms don’t last long — about 1 to 3 days.

Can I do anything to reduce side effects from the vaccine?

You should wait until after being vaccinated to see how you feel. If you do experience side effects, it is OK to take an over-the-counter drug like Advil or Tylenol to lower a fever, reduce chills, or relieve a headache or body aches.

Can the COVID-19 vaccine cause cancer?

No. None of the vaccines interact with or alter your DNA in any way. They cannot cause cancer. There is no truth to the myth that somehow the COVID-19 vaccine could inactivate the genes that suppress tumors.

Messenger RNA (mRNA) is not the same as DNA and cannot be combined with DNA to change your genetic code. The mRNA vaccines use a tiny piece of the virus’ genetic code to teach your immune system how to make a protein that will trigger an immune response if you get infected. The mRNA does not enter the nucleus of the cell (the part that contains your DNA).

Can I get the shot at the same time as my flu shot or my RSV shot?

You can get the flu and COVID-19 shot at the same time. However, the RSV shot should be taken separately and at least 2 weeks apart from the other vaccines.

Read about the RSV vaccine.

If the 2023-2024 COVID-19 vaccine provides better protection, can I get it as my primary shot?

Yes. Unvaccinated people should get this vaccine as their very first shot.

Can I still get the original COVID-19 vaccine? Can I get a bivalent vaccine?

No. FDA authorization for the original vaccines were removed in April 2023. The 2023-2024 vaccine is the only COVID-19 vaccine available in the U.S.

I was infected with COVID-19 recently. Should I get the 2023-2024 COVID-19 vaccine? When?

People who have been infected with COVID-19 should still get vaccinated. We know from past research that vaccination after infection increases protection against future infection and severe illness.

People who were recently infected can wait 2 months to get their shot.

Should I get the same brand of the 2023-2024 COVID-19 vaccine as my other shots? Or can I mix and match between brands?

Either is OK. You can switch brands or stick with what you got in the past.

Once I’m vaccinated, do I need to wear a mask?

You should follow the rules and guidance in your community for situations including businesses, schools, transportation hubs, and hospitals.

Our visitor policy has information about when you need to wear a mask at MSK.

In all indoor and outdoor settings, it’s especially important for you to wear a mask if:

  • You are immunocompromised
  • You are not up to date on your COVID-19 vaccinations
  • Physical distancing is not possible

How can I get a 2023-2024 COVID-19 vaccine?

Starting October 2, we can vaccinate our patients aged 12 and older during their appointment. During your appointment, tell your care team that you want to get the COVID-19 vaccine.

If you don’t have an upcoming MSK appointment or if you don’t want to wait to get your shot at MSK, you can use these websites to get a vaccine somewhere else:

October 2, 2023