Early Omicron infection may not have protected seniors enough from later variants: Canadian study – CTV
Aug. 22, 2023
A new study involving Canadian researchers has found that an early Omicron infection may have left some seniors more prone to reinfection from a later version of the COVID-19 variant.
Researchers from McMaster University in Hamilton, Ont., published a study Monday in eClinicalMedicine, a journal from The Lancet, which looked at 750 vaccinated seniors in Ontario retirement and long-term care homes, including both public and private, as well as non-profit and for-profit facilities.
The researchers say all of the initial infections occurred during the wave of Omicron subvariants BA.1 and BA.2 in early 2022.
All of the reinfections, meanwhile, happened later that summer when BA.5 was the dominant subvariant.
“We found that some individuals had normal immune responses after the first infection, while others had very low levels of protective antibodies, which we believe was one contributing factor to why they got reinfected,” McMaster immunologist Dawn Bowdish, corresponding author for the study and a Canada Research Chair in aging and immunity, said in a news story from the university.
