A vial of Johnson & Johnson's Covid-19 vaccine. Eduardo Sanz/Europa Press via Getty Images
A major new study has suggested that people who received the J&J vaccine might have a stronger immune response to a Moderna/Pfizer booster.
J&J recipients had higher levels of antibodies following a Moderna/Pfizer shot than a second J&J jab.
But, higher levels are not always a sign that a person is more immune to the coronavirus.
The first US study has shown that you can mix boosters of Moderna and Pfizer with Johnson & Johnson's COVID-19 shots. However, boosting J&J using Moderna or Pfizer might prompt a stronger immune reaction, at least initially.
Funded by the US National Institutes of Health (NIH), this new study showed that mixing and matching COVID-19 vaccinations is perfectly safe.
"What the study shows, regardless of what an individual has received previously, getting boosted using one of the three vaccines we evaluated, from Moderna to Janssen to Pfizer led to good antibody reactions in each of these groups," Dr. Robert Atmar, Baylor College of Medicine, told Insider shortly after his new data were released.
The study included 458 participants from 10 US medical centers who had been fully vaccinated using Moderna's, Pfizers or J&J [Janssen] vaccines. The volunteers were then given one of the three shots. This gave rise to nine mix-and-match combinations. The blood of the volunteers was tested periodically over the following month by researchers to compare their levels of neutralizing antibodies, which are virus-fighting proteins.
This study shows that booster shots from Moderna, Pfizer, and J&J all increase antibody levels. However, a booster from Moderna or Pfizer's vaccine produces a stronger response than a booster from J&J. It's similar to the results of European researchers who found that AstraZeneca's vaccine was boosted with Pfizer.
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People who received their first shot from J&J saw strong responses from Moderna or Pfizer boosts.
People who received J&J's initial vaccine showed the greatest improvement in neutralizing antibodies. Although they are a poor proxy for measuring initial vaccine-induced immune response, it was clear that this vaccine had made a significant difference.
A J&J booster shot increased neutralizing antibody levels by an average of 4.2-fold in this group. J&J recipients who received a Moderna shot saw an average 76-fold increase of antibodies. A Pfizer booster produced a 35-fold increase. These differences were statistically significant, so it is highly unlikely that they are due to chance.
Chanei Henry is the senior research coordinator of molecular microbiology and molecular virusology at Baylor College of Medicine. She prepares a COVID-19 vaccination during the mix-and-match trial. Baylor College of Medicine
Researchers warn that the study, which included only 50 participants in each group, is not large enough to compare vaccine booster combinations. The trial's short follow-up (of one month) also doesn't give us any insight into how long-lasting each booster's protection might be.
Atmar warned that the study was not intended to make any comparisons between groups, but rather "to provide rapid data for public health decisions."
He acknowledged that "it is natural for people to compare things." The tables clearly show the stark differences.
These same trends were observed for neutralizing antibody titres, which is a longer-lasting (but still not perfect) representation of vaccine-induced immunity.
Immunity is not all about antibodies
Atmar reminded us that we don't all need mRNA boosters.
He said, "I don’t think we’re going to end up boosting individuals every six months."
Although antibodies play a critical role in the body's initial immune response to infection, other components of immune memory such as the cellular immune response were not measured in this study.
Side effects aside, the most common complaint after a boomer was mild arm pain. This is what more than 70% of all patients from all mix-and-match groups experienced.
This week, health regulators will vote on boosters
This highly anticipated study includes some of the most important research regarding the safety and immunogenicity boosters. It comes at a crucial time: A panel of FDA experts will meet on Thursday and Friday to discuss Moderna boosters and J&J boosters. Next week, a CDC panel will convene on the same topic. (Both the FDA and CDC approved third doses of Pfizer last month.
FDA has already inspected J&J's application for a booster shot. Scientists at the FDA highlighted a lackluster clinical trial supporting boosters at six-months.
Business Insider has the original article.
