Many people will be able to “mix” COVID-19 booster shots. That is, another COVID-19 vaccine will be available for boosters, the Food and Drug Administration (FDA) announced Wednesday (October 20).
Studies and real-world data show that this mix-and-match approach is safe and in some cases may be more effective than not mixing.So should you get a booster vaccination Is it different from your original dose? Live Science spoke with two experts who agreed that the vaccine mix was completely safe, but their recommendations were slightly different.
FDA Approved booster dose For adults with immunodeficiency, adults 65 years or older or with underlying illness, or adults at high risk of exposure to COVID-19. Those who have been vaccinated twice with the Pfizer-BioNTech or Moderna vaccine are considered fully vaccinated and are eligible for a booster at least 6 months after the last vaccination, but all who have been vaccinated once with the Johnson & Johnson vaccine. Adults are eligible for vaccination. Boost immunization 2 months after injection.
The data suggest that in a person who has been vaccinated with one of the two mRNA vaccines, Pfizer or Moderna, receiving a booster vaccination with the other mRNA vaccine is likely to be equivalent to vaccination with the same vaccine. I have.However, for those who are the first to receive the Johnson & Johnson vaccine, getting a Pfizer or Moderna booster can be a much better stimulus. Immune response Rather than receiving a second Johnson & Johnson shot.
Evidence of mixing
The FDA’s announcement to allow mixing and matching follows the early results of ongoing National Institutes of Health (NIH) research. On October 15, a group of researchers published the results of their study, which has not yet been peer-reviewed and has been posted as a preprint. medRxiv, To the FDA’s expert panel.
Researchers tested nine different combinations of Johnson & Johnson, Modana, and Pfizer vaccines given to 458 participants and found that the combination was safe and highly effective.After receiving a booster shot, the circulation of antibodies, including neutralization, increased significantly. antibody — A molecule that binds to the virus and blocks cell infection — against SARS-CoV-2, the virus that causes COVID-19.
In people who received boosters different from the original vaccine series, neutralizing antibody levels increased 6.2-76-fold, depending on the combination of vaccines received. Those who received the same vaccine booster as the original vaccine had a 4.2- to 20-fold increase in neutralizing antibody levels. This also depends on which vaccine you have given.
The greatest increase in neutralizing antibody levels was among those who first received a single dose of Johnson & Johnson vaccine and then a Moderna booster. Participants in this group had an average 76-fold increase in antibodies compared to before 15 days after receiving the booster. The lowest increase-but nevertheless-was the person who received the Johnson & Johnson vaccine at both the original dose and booster immunity. (The Moderna booster in this study was given at the same dose as the original vaccine, but the FDA approved half the dose of the commonly given booster shot).
Average increase in neutralizing antibody levels
|Pfizer-BioNTech Booster||Modana booster||Johnson & Johnson Booster|
|Double dose Pfizer-BioNTech initial||20 times||31.7 times||12.5 times|
|Initially twice Moderna||11.5 times||10.2x||6.2x|
|First dose of Johnson & Johnson||35.1x||75.9x||4.2x|
As part of the NIH study, levels were measured 15 days after the booster shot.
For those who were first vaccinated with the mRNA vaccine, receiving a booster vaccination with another mRNA vaccine was less dramatic, but it also had some minor benefits.
The number of people who first received Pfizer and then boosted with Pfizer increased by 20 times, while the number of people who boosted with Moderna increased by 31.7 times. Those who received Moderna first and then boosted with Moderna increased 10.2 times, while those who received Moderna first and then boosted with Pfizer increased 11.5 times.
“Based on the data we saw and everything we learned about our experience in other countries, I probably gave the first person who received J & J the mRNA vaccine as a second vaccination instead of the second J & J vaccine. Dr. Carlos Malvestt, an infectious disease doctor at The Ohio State University Wexner Medical Center, said he was vaccinated as the first dose.
However, for those who have been vaccinated with either of the two mRNA vaccines, getting the same or opposite boosters is fine. Malvestutto told Live Science.
Dr. Ericsio Epenha, Global Health Director of Northwell Health in New York, agreed.
“What is clear from the data is that one of the two mRNA vaccines currently available gives the best immune response,” he told Live Science by email. Therefore, people who have been vaccinated with the Johnson & Johnson vaccine (or the AstraZeneca vaccine, which has the same composition as the Johnson & Johnson vaccine and is approved in other countries) will have a stronger immune response when vaccinated with the mRNA booster.
“What’s not clear and probably doesn’t make sense is the switch between mRNA vaccines,” he added. “”
There does not appear to be a statistically significant difference in the effectiveness of these two vaccines, and they work in a very similar way. “
Still, not everyone agrees.
“If we can guarantee that we are there [are] Personal use of all three US-approved vaccines, including those vaccinated by Johnson & Johnson and Rodney Rohde, a professor at Texas State University and chair of the university’s clinical laboratory science program. Is recommended. This is because “boosting everything looks good” and there are longer-term data on the effectiveness of boosting with the same vaccine. Still, “I think it’s safe to mix and match. Make it available,” he told Live Science.
Real world data
This NIH study is not the only data showing possible potential safety benefits of vaccine mixing and matching. Countries such as Turkey have been mixing and adapting vaccines for some time, boosting those who have been vaccinated twice with the Chinese-made Sinovac vaccine to those who have been vaccinated once or twice with the Pfizer vaccine.
Data from the UK and Canada taking a second dose of Pfizer in addition to the original dose of the adenovirus vaccine AstraZeneca COVID-19 vaccine, which uses the same platform as Johnson & Johnson, also match the mix. Shows that it is safe and very effective.
Even before the NIH findings, these hands-on studies revealed that mixing and matching were safe and stimulated a strong immune response. “What we saw was basically the same type [adverse reactions] “It’s seen on the first and second doses of these vaccines, but nothing gets worse or scary,” Malvestot said. “Evidence shows that it’s very safe.” Said.
In addition, some evidence suggests that mixing and matching these vaccines may lead to a broader immune response that may respond better to future SARS-CoV-2 mutants. It suggests, Malvestutto said. Still, many questions remain as to how effective this approach is in other parts of the immune response.
“Immune isn’t just about antibody levels. There are other parts of the story,” Malvestutto said. NIH research focused only on antibody levels. Another very important part of the immune response is what is known as a memory cell. It circulates in the body after neutralization. When antibody levels drop and are exposed to pathogens, it encourages the immune system to make more targeted antibodies.
We still need data on whether the mixed-and-match approach has better, worse, or the same effect on the generation of these memory immune cell responses, Malvestutto said.
In any case, the data suggest that mixing and matching are safe and effective. But the most important message is to get a booster if people have completed their first vaccination and are in a high-risk group.
Originally published in Live Science.
Editor’s Note: The article was updated at 2:30 pm Eastern Standard Time to clarify that all adults who first take a Johnson & Johnson shot are eligible to get a booster.
Should I mix the COVID-19 vaccine?
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