Vaccinologist Kizzmekia Corbett-Helaire on COVID-19 vaccines, boosters, and more

Bandage after applying vaccine

November 8, 2023 – Kizzmekia Corbett-Helaire, assistant professor of immunology and infectious diseases at Harvard T.H. Chan School of Public Health, played a key role in developing the mRNA-based platform that enabled the creation of COVID-19 vaccines that have protected millions. In this Q&A—adapted from recent videos posted on Harvard Chan School’s Instagram—she answers questions about COVID-19 vaccines and boosters, as well as other vaccines.

Kizzmekia Corbett-Helaire
Kizzmekia Corbett-Helaire

Q: Why should you get a COVID booster?

A: You should get a COVID booster so that you are optimally protected against COVID-19 severe disease.

Q: If you got COVID this year, should you still get boosted?

A: If you had COVID over two months ago, you should still get boosted with the COVID vaccines that are available.

Q: How long do COVID boosters last?

A: COVID boosters last in normal, healthy people for up to a year.

Q: How long should we wait between COVID boosters?

A: It is recommended for immunocompromised people that they get their COVID boosters two months after receiving their last shot. For normal, healthy people, it is recommended that you get your COVID boosters now.

Q: How do boosters work?

A: Boosters work like the snooze button on your alarm clock. Think about your body or your immune system like having gone to sleep and the vaccine as an alarm clock. The boosters come in every year or so and act like a snooze button to re-alert your immune system to wake up.

Q: How do the mRNA vaccines work?

A: The “M” in mRNA actually stands for messenger. So, that’s exactly how the vaccines work. They message your body to make proteins. In the case of the COVID-19 mRNA vaccine, it is telling your body or sending a message to your body to make a specific protein that is found on coronaviruses. The spike protein. When your body makes that spike protein after having gotten the vaccine, then your body is alert to that spike protein and creates antibodies and other types of immune cells that recognize that spike protein.

Q: What are the new COVID boosters and how are they different from the old ones?

A: The virus that causes COVID-19 sometimes varies. So, over the course of the pandemic, the virus has gotten some mutations. Because of that, we have to update the vaccines, and the current booster vaccine is very closely related to the current COVID-19 virus that is circulating.

Q: What options do I currently have for COVID-19 vaccines/boosters?

A: Recently the FDA authorized a new COVID-19 vaccine in the United States. That vaccine is made by a company called Novavax and it is a vaccine that is a protein-based vaccine. So, instead of having the messenger RNA tell your body to make the protein, the vaccine company is instead giving you the protein in the vaccine form. With that being said, you now have the option to either be boosted with the Novavax protein-based vaccine or the messenger RNA vaccines from Moderna or Pfizer.

Q: Does it matter which manufacturer’s booster we take after the primary series?

A: It does not matter which manufacturer’s booster you take after the primary series.

Q: If a person has never previously been vaccinated against COVID, is it enough to get the current booster, or do they have to first get the other shots that were offered in the past?

A: Even if you’ve never been vaccinated, you only have to get the current shot. People aged 12 and older should get either one dose of the Pfizer or Moderna vaccine, or two doses of the Novavax vaccine. Children ages 5 to 11 should get one dose of either the Pfizer or Moderna vaccine.

Q: What vaccine combinations are safe to take together?

A: I know it can be overwhelming during this season to be getting several different vaccines, but you should know that it is safe to get your flu vaccine and your COVID-19 vaccine together. In fact, that’s what I did. If you are over the age of 60, you can also receive the newly approved respiratory syncytial virus (RSV) vaccine as well.

Q: Which vaccines can be given to children?

A: I know it’s really confusing with children, especially with the new [Novavax] vaccine coming on board. But you should know that if your child is six months or over, they can get boosted with the mRNA vaccines just as they would normally. The Novavax vaccine can now be given to children over the age of 12.

Q: Other tips for staying healthy?

A: It is extremely important that you get vaccinated and tell your family and friends to get vaccinated as well. But also remember that if you feel comfortable, you should wear your mask in public areas, particularly when there are lots of people, to keep yourself safe during this season.

Feature photo: iStock/andreswd

Photo of Kizzmekia Corbett: Anna Webster