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Longer intervals between COVID-19 shots can increase immunity, Canadian study suggests

Peer-reviewed study used blood tests from paramedics
UBC research has yielded results suggesting waiting longer between COVID-19 vaccinations leads to better immunity. Pictured here vaccinations in Montreal in March. (THE CANADIAN PRESS/Paul Chiasson)

University of B.C.-assisted research suggests waiting longer between first and second COVID-19 vaccination doses provides better immunity.

According to a press release, a peer-reviewed study with principal investigator Brian Grunau, UBC department of emergency medicine professor, found that “a longer dose interval (of mRNA vaccines, such as Pfizer and Moderna) leads to a stronger immune response.” The research, published Tuesday (Nov. 30), compared blood tests from 186 paramedics, some who received their shots in under the recommended four weeks and others who were vaccinated after six to seven weeks.

“We found significantly higher levels of antibodies in individuals who had longer vaccine intervals, and this was consistent regardless of which mRNA vaccine was administered,” Grunau said in the press release.

With half of the people in the world vaccinated, the research has “implications for the ongoing global vaccination effort,” stated the press release. Increasing time between doses could see better “long-term immune response” and lead to better “community-level access” to first vaccine shots, it said.

“This longer interval strategy enables early access to first doses in the population and ensuring the best protection possible with the two-dose series,” said Grunau.

People who participated in the study are part of the larger COVID-19 Occupational Risks, Seroprevalence and Immunity among Paramedics project, said the press release, a Canada-wide study looking at the pandemic’s effect on paramedics.

Research was funded by money from the Government of Canada’s COVID-19 Immunity Task Force.

According to the latest COVID-19 numbers from the health ministry, there were 375 new cases reported in the province and 88.4 per cent of eligible adults in the province have received two vaccine shots.

RELATED: B.C. calls on retired medical staff to help with COVID-19 vaccinations

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Karl Yu

About the Author: Karl Yu

After interning at Vancouver Metro free daily newspaper, I joined Black Press in 2010.
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