Research shows COVID-19 booster increases durability of antibody response

New research from the University of VirginiaSchool of Medicine speaks to the benefits of a COVID-19 booster.

The new findings shed light on how mRNAboosters - both Pfizer and Moderna - affect the durability of our antibodies toCOVID-19. A booster, the researchers report, made for longer-lasting antibodiesfor all recipients, even those who have recovered from a COVID-19 infection.

"These results fit with other recent reportsand indicate that booster shots enhance the durability of vaccine-elicitedantibodies," said senior researcher Jeffrey Wilson, MD, PhD, of UVA Health'sDivision of Asthma, Allergy and Immunology.

Tracking COVID-19 antibodies

Wilson and his collaborators looked atantibody levels following a booster in 117 UVA employee volunteers and comparedthose results with the levels seen in 228 volunteers after their primaryvaccination series. Antibody levels one week to 31 days after the primaryseries and booster were similar, but the boosted antibodies stuck around longerregardless of whether the person had had COVID-19.

"Our initial thought was that that boosterswould lead to higher antibody levels than the primary vaccine series, but thatwas not what we found," said researcher Samuel Ailsworth, the first author of anew scientific paper outlining the findings. "Instead, we found that thebooster led to longer lasting antibodies."

Antibody levels naturally decline over timeafter an infection or after vaccination, but higher levels are thought to bemore protective. Thus, longer-lasting antibodies would be expected to providemore sustained immunity against severe COVID-19.

The researchers found that the antibodiesgenerated by the Moderna booster proved longer lasting than those generated bythe Pfizer booster. Moderna's antibody levels exceeded Pfizer's out to fivemonths, the end of the study period. Although the findings were statisticallysignificant, Wilson notes that both mRNA vaccine boosters provide enhanced andfairly similar levels of protection against COVID-19 in recently publishedlarge epidemiologic studies.

Because the frequency of COVID-19 infectionsin the community was relatively high when the boosters were being given, theauthors also studied the effect of COVID-19 infection on antibody levels. Thefindings suggest that the "enhanced antibody durability observed after boostervaccination was not explained by hybrid immunity," the researchers report intheir paper.

The new results are the latest from Wilson'steam tracking the antibody response to the COVID-19 vaccines over time. Theresearchers previously found that after the primary vaccination series theantibodies generated by Pfizer's COVID-19 vaccine rose more slowly and declinedmore quickly than those generated by the Moderna vaccine. That study also foundthat older recipients of the Pfizer vaccine generated fewer antibodies than didyounger recipients – but this wasn't the case for Moderna, where age did notappear to be a factor.

In the latest results, younger boosterrecipients initially generated more antibodies than did older recipients, butthis difference disappeared with time.

Wilson notes that this study adds to theaccumulating evidence that boosters are an important of protecting thecommunity from COVID-19. "Although only about half of the U.S. population thatis eligible for a booster has received one, it is increasingly clear thatboosters enhance the protection that is conferred by the primary series mRNAvaccines alone," he said.

Reference:

Jeffrey Wilson et al, JOURNAL: Annals ofAllergy Asthma & Immunology,DOI: 10.1016/j.anai.2022.10.003