The findings raise questions about the optimal timing of the second dose of the vaccine for older adults.
“Results from this study in long-term care facilities in Vancouver reveal that individuals of advanced age, following the first dose of a two-dose vaccination regimen, are less able to generate as strong an antibody response, both in terms of magnitude and function, compared to adults of younger age,” says Dr. Marc Romney, clinical associate professor in UBC’s department of pathology and laboratory medicine, and medical leader for medical microbiology and virology at St. Paul’s Hospital, Providence Health Care. “It will be important to assess whether this observation extends to older persons living in the community as this may inform the optimal timing of the second dose for this population.”
Dr. Romney and the research team, co-led by Dr. Zabrina Brumme of the BC Centre for Excellence in HIV/AIDS and Dr. Mark Brockman of Simon Fraser University, analyzed blood samples collected in late 2020 and early 2021 from residents and staff of long-term care homes in the Metro Vancouver area.