Vinh DC, Gouin JP, Cruz-Santiago D, Canac-Marquis M, Bernier S, Bobeuf F, Sengupta A, Brassard JP, Guerra A, Dziarmaga R, Perez A, Sun Y, Li Y, Roussel L, Langelier J, Ke D, Arnoldd C, Pelchat M, Langlois MA, Zhang X, Mazer BD. Real-world serologic responses to extended-interval and heterologous COVID-19 mRNA vaccination in frail older people (UNCoVER): and interim report from a prospective observational cohort study. Lancet Healthy Longevity 21 Feb2022; doi: 0.1016/S2666-7568(22)00012-510.1101/2021.09.16.21263704
The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.
Findings from a real-world vaccination study of seniors residing in long-term care facilities were recently published in the Lancet Healthy Longevity. It was conducted by investigators from the CITF-funded UNCoVER study, including Dr. Donald Vinh of the Research Institute of the McGill University Health Centre (RI-MUHC) and Dr. Marc-André Langlois of the University of Ottawa, and the CITF Secretariat (Dr. Bruce Mazer, Associate Director, Strategy, affiliated with the RI-MUHC). The study found that dual Pfizer and Moderna vaccines and a mix-and-match series elicited similar antibody responses four weeks after the second dose.
Older adults residing in long-term care facilities in Quebec, with or without a previously documented SARS-CoV-2 infection, received two doses of an mRNA vaccine (Pfizer-BioNTech’s Cominarty and/or Moderna’s Spikevax) with a 16-week interval between doses. This study included individuals who received either two doses of the same vaccine (homologous vaccination) or a mix-and-match regime (heterologous vaccine combination).
- Older people without a previous SARS-CoV-2 infection exhibited lower antibody responses after the first dose compared to those who were previously infected. However, four weeks after the second dose, both groups achieved comparable levels of antibodies.
- Four weeks after the second dose, antibody levels were similar in individuals who had received two doses of Cominarty or Spikevax or a combination of the two, thereby supporting their interchangeability.
- Age, biological sex, and underlying comorbidities did not affect antibody production in response to mRNA-based COVID-19 vaccines.