Is Moderna, Pfizer or J&J Covid-19 Booster Shot Best for You?

New guidance on Covid-19 booster shots answers a long-standing question: Can you mix vaccine doses?

The US Food and Drug Administration said on Wednesday that people may get boosters that are different from the vaccine they originally received. So if you got Pfizer six months ago, you can get a booster from Moderna or Johnson & Johnson, as long as you’re eligible otherwise.

The FDA does not recommend specific combinations, or say that one brand is a better booster than another.

On Thursday, a Centers for Disease Control and Prevention advisory panel also voiced its support for mixing primary vaccines with a different booster dose.

With Vaccine Mixing Greenlight, how can you know which booster is best for you? Here’s what the research says.

Is it okay to mix covid-19 vaccines?

The most comprehensive data on mix-and-match is a 458-person National Institutes of Health study that tested a combination of Pfizer, Moderna, and J&J vaccines. Preliminary results of the trial, which have not yet been peer reviewed, were presented at an FDA meeting last week.

The study found that boosting with a different vaccine is safe, and that the boosters increase antibody levels, no matter what the combination.

“I don’t think there are any losers here,” says Katherine Edwards, a professor of pediatrics at Vanderbilt University Medical Center. “Whether you get the same vaccine or a different one, it’s going to boost your immune response.”

The NIH study looked at antibody levels 15 to 29 days after the booster, says Kirsten Laik, MD, a professor of medicine in the Center for Vaccine Development and Global Health at the University of Maryland, who co-chairs the NIH Mix-and-Take. match study.

Which booster combination works best?

In the NIH study, people with the highest overall antibody levels were those who received the Moderna vaccine and Moderna as a booster for their first two doses. Then came the people who got the Pfizer Vaccine and Moderna Booster, followed by Moderna and Pfizer Booster.

One combination promoted far fewer antibodies than the rest: the original one-dose J&J shot was followed by another shot of J&J, which increased antibodies fourfold. By comparison, a Moderna booster increased antibodies by 76-fold after a basic J&J shot, while a Pfizer-BioNtech booster increased them by 35-fold.

Dr. Edwards says, “antibody levels that are higher are probably associated with longer duration of protection. So I think a lot of people who got Johnson & Johnson initially might decide they got mRNA.” The vaccine will be available.” Referring to Pfizer and Modern Shots.

It is more complicated to determine which booster is most appropriate than just looking at antibody levels in the study. The NIH study tested boosting with a single dose of Moderna containing 100 micrograms of antigen, substances that trigger the production of antibodies, in equal amounts in each of the initial two Moderna shots. Now the authorized Moderna booster dose will be 50 micrograms.

It is also unclear what level of antibodies translates to real-world protection. Scientists don’t know how many antibodies are needed to keep you from getting sick.

Antibodies are not the only way the body fights infection. The J&J vaccine produces a strong T-cell response, the part of the immune system that can kill virus-infected cells and plays a major role in preventing serious disease. The NIH study is awaiting data on T-cell responses to different combinations of vaccines, Dr. Laik says.

The NIH study did not compare the overall long-term effectiveness of the individual boosters face-to-face.

“This was a laboratory study looking at the antibody response, not looking at effectiveness over time, so it would be very difficult to make a recommendation based on effectiveness,” said Lena, an emergency physician and public health professor at George Washington University in Washington. Wayne says. .

Who can get the booster?

Under the latest FDA authorizations, every authorized vaccine now has a booster shot. In addition, any adult who has received the J&J vaccine can receive a booster from Pfizer, Moderna, or J&J at least two months after the single-dose shot. People who initially received the Pfizer or Moderna vaccination can receive a booster at least six months after their second dose, as long as they are seniors or at high risk because of underlying medical conditions or their workplace . And those who are immunocompromised are eligible for a Pfizer or Moderna booster starting August.

Some people who fall outside those criteria have managed to get boosters anyway because many pharmacies allow people to self-verify for their eligibility and some doctors are more lax.

An edge for Pfizer and Moderna in studies outside the US

The NIH results are similar to studies conducted in other countries, such as the com-CoV study conducted at the University of Oxford, which helped develop the AstraZeneca vaccine in the United Kingdom. The researchers studied mixing and matching Pfizer’s vaccine with AstraZeneca, which is made using the same technology as J&J. There, too, researchers found that people who received the AstraZeneca shot followed by Pfizer produced more antibodies than those who received two AstraZeneca shots four weeks later.

A new study out of Sweden found that a shot of AstraZeneca with a second dose of Pfizer or Moderna resulted in fewer cases of symptomatic Covid-19 than giving people two doses of the AstraZeneca vaccine.

But neither was as effective as giving people two doses of the Pfizer or Moderna vaccines, says Peter Nordstrom, first author of an October 17 study in the journal Lancet Regional Health Europe and professor of geriatric medicine at Ume University in Sweden.

What else should I consider when mixing and matching boosters?

Instead of endorsing a combination of shots for everyone, Dr. Laik says that evidence that any mix of three US-approved vaccines is safe should let people with special health considerations make the best choice for themselves.

For example, young men who may experience the very rare side effect of myocarditis, or inflammation of the heart, after an mRNA vaccine may want to receive the J&J booster, she says. And women under 50 who have received the J&J vaccine may opt for the mRNA vaccine to avoid potential blood clotting complications.

“It’s not as black and white as, ‘Everybody can have it and everyone can have it,'” she says.

Is there a difference between Pfizer and Moderna in vaccine boosters?

Some scientists say the modern vaccine produces higher levels of antibodies than the Pfizer vaccine, giving it an edge as a booster.

Still some people experience more side effects with Moderna, though mostly moderate, such as fatigue, muscle aches, and chills. And the antibody differences between Pfizer and Moderna aren’t huge.

“From the data we’ve got, Moderna is doing a little better. We’re not talking orders of magnitude,” says Deepta Bhattacharya, a professor of immunobiology at the University of Arizona College of Medicine in Tucson.