Nursing home residents who receive a bivalent COVID-19 mRNA vaccine show signs of substantial immune system response to SARS-CoV-2, including omicron variants, federal researchers have found.
The findings offer evidence that the bivalent booster vaccine is protective in the nursing home population, no matter whether a resident has previously been infected or has received monovalent vaccine doses, the researchers said.
The ongoing study has followed 233 volunteer residents of 28 community nursing facilities and veterans homes. Participants received their primary mRNA vaccination series of monovalent shots by February 2021 and a first booster dose within nine months afterward. Some 78% of participants received a second monovalent booster dose. All participants then received a bivalent booster dose between September and November 2022.
Antibody response increases
SARS-CoV-2 antibody levels waned within months after the monovalent vaccinations, including in residents who had had COVID-19, an analysis showed. But the antibody response increased after the COVID-19 bivalent booster among those with and without a prior infection.
“These findings indicate that nursing home residents can benefit from bivalent booster vaccination, substantially broadening their immune response to tested omicron variants,” the researchers reported in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report.
To reduce the risk for infection, severe disease and death, residents and facility staff members “should stay up to date with recommended COVID-19 vaccines, including a bivalent booster dose if two or more months have elapsed since their last COVID-19 vaccine dose,” they concluded.