Mixing COVID-19 Booster Vaccines Found Effective
A non-peer-reviewed phase 1/2 study's results published on October 13, 2021, included less than 500 adult volunteers who were fully vaccinated against COVID-19 and received booster doses of different COVID-19 vaccines to determine the safety and immunogenicity of mixed boosted regimens.
A booster dose could be either a second or third vaccination, depending on with COVID-19 vaccine was administered.
The limited, accelerated study included 458 individuals: 154 received mRNA-1273 (SpikeVax), 150 received Ad26.CoV2.S (Janssen), and 154 received BNT162b2 (Comirnaty) booster vaccines.
These researchers stated 'reactogenicity was similar to that reported for the primary series.'
And booster vaccines increased the neutralizing activity against a D614G pseudovirus (4.2-76-fold) and binding antibody titers (4.6-56-fold) for all combinations.
Homologous boost increased neutralizing antibody titers 4.2-20-fold, whereas heterologous boost increased titers 6.2-76-fold.
Day 15 neutralizing and binding antibody titers varied by 28.7-fold and 20.9-fold, respectively, across the nine prime-boost combinations.
"Although the vaccines currently authorized by the U.S. Food and Drug Administration offer strong protection against COVID-19, we need to prepare for the possibility of needing booster shots to counter waning immunity and to keep pace with an evolving virus," said NIAID Director Anthony S. Fauci, M.D., in June 2021.
This NIH co-funded study concluded by says 'Homologous and heterologous booster vaccinations were well-tolerated and immunogenic in adults who completed a primary Covid-19 vaccine regimen at least 12 weeks earlier.'
The U.S. FDA Vaccines and Related Biological Products Advisory Committee scheduled meetings to review information regarding COVID-19 vaccines on October 14-15, 2021.