SARS-CoV-2-related mortality decrease in nursing home residents given multiple COVID-19 boosters

Two doses of COVID-19 mRNA vaccines in the primary series and a booster dose induce a strong antibody response, however, this response can be weak in people older than 80 years.

For adults aged more than 80 years, the Public Health Agency of Sweden has endorsed booster doses every 6 months.

We have tracked the antibody concentrations in residents of 115 nursing homes every three months with care staff assisted self-collected quantitative microsampling of blood and collected national register data on age, sex, and mortality date linked to individual nursing home residents (appendix pp 2–3). We showed that people with the lowest concentrations of spike-specific immunoglobulin G (IgG) after the third dose of the COVID-19 vaccine had elevated risk of SARS-CoV-2-related mortality.