A study across 239 Genesis HealthCare nursing homes has found no evidence of adverse reactions to COVID-19 booster shots among residents. The news arrives alongside results from two new studies showing current booster efficacy against the omicron variant.

Investigators from Brown University and Genesis compared rates of adverse events between nursing home residents who had received an mRNA COVID-19 vaccine booster dose and their peers who had yet to receive a booster. The primary mRNA vaccine series was delivered at least six months before Sept. 22, 2021 and participants’ third booster doses were given between that date and February 2, 2022.  

“No safety signals were detected,” in a 14-day post-vaccination period, reported veteran nursing home researcher Vincent Mor Ph.D., and colleagues.

Quick immune response

Another study, published Thursday in the journal Nature, may help answer the question of how effective these boosters are against omicron. Study participants given three doses of an mRNA vaccine were able to quickly produce antibodies against the variant, researchers from The Rockefeller University in New York reported. 

“These data help explain why a third dose of a vaccine that was not specifically designed to protect against variants is effective against variant-induced serious disease,” they wrote.

A cohort study published Friday, meanwhile, has found a “persisting and robust” immune response to omicron mutations in patients with different vaccination histories. 

“The results mean that both vaccination and previous infection with COVID-19 likely prevent severe illness and death from the omicron strain,” reported the Center for Infectious Disease Research and Policy.

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