Volunteers were divided into groups and given either an additional dose of their initial vaccine or a booster shot from a different firm. Two weeks and four weeks after the boosters were administered, antibody levels were assessed.
All the combinations increased antibody levels, but Pfizer’s and Moderna’s boosters looked to be the most effective. According to the study, people who received a booster dose of either the Moderna or Pfizer vaccinations had a more significant rise in antibody responses than those who received an extra dosage of J&J.
The results of the study demonstrated that recipients of Moderna or Pfizer’s original vaccines might simply exchange third doses, with similar results. Volunteers who had previously received the J&J vaccine had a more significant immune response after receiving a booster from Pfizer or Moderna.
According to the researchers, there were no significant side effects associated with the additional doses, and no new symptoms appeared after subjects received the booster shots. After receiving their boosters, two subjects vomited; one had got Moderna and the other J&J. Another two patients who received a J&J booster complained of weariness or insomnia.
The one-dose vaccination from J&J employs an adenovirus, while the two-dose vaccines from Pfizer and Moderna use mRNA technology. Scientists believe that by combining vaccinations from different platforms, patients will be able to acquire broader protection against the coronavirus and its novel variations.
The findings are likely to stoke controversy over whether more vaccination doses should be given to the millions of Americans who received J&J’s immunizations. Unlike Pfizer and Moderna’s two-shot mRNA vaccines, J&J hoped to provide a one-shot treatment that would protect the population sufficiently to help end the coronavirus pandemic.
According to company data released Sept. 21, the second dosage of J&J’s shot performs similarly to mRNA vaccines, improving protection from symptomatic infection to 94 percent from 72 percent when given two months after the initial dose in the United States. The FDA stated in a separate document issued earlier Wednesday that evidence presented by J&J shows that recipients may benefit from a second shot two months after the first.
According to regulators, J&J’s single-shot vaccine’s effectiveness in trials and real-world research “is consistently less than the highest effectiveness estimates for the mRNA COVID-19 vaccines.” The findings, which were released on Wednesday, are due to be presented at a major FDA vaccine advisory committee meeting on Friday.