Boosted immunity: Study shows longevity of COVID-19 booster vaccinations

Boosted immunity: Study shows longevity of COVID-19 booster vaccinations

Are you thinking about getting a booster shot in the spring? A new study from the Center for Disease Modeling at York University's Faculty of Science shows that immunity lasts much longer after a COVID-19 booster vaccination than after the primary vaccination alone. These findings include, among other things, sometimes “unintuitive” insights into how factors such as age, gender and comorbidities influence and do not influence the immune response.

The authors of the study–York post-doctoral researchers Chapin Korosec and David Dick, Professor of Applied Mathematics Iain Moyles and Professor James Watmough from the University of New Brunswick–used health data submitted to the Covid Immunity Task Force project from more than 150 people who received either Pfizer-BioNTech or Moderna COVID-19 vaccines to study how immunity persists over time.

Our approach as mathematicians is to build mathematical models of the immune system and then calibrate these models using health data to improve our understanding of the human immune system. It was really interesting to see that the SARS-CoV-2 booster dose provides such a huge increase in protective longevity capacity compared to the two-dose primary vaccination.”

Chapin Korosec, lead author of the study

Published in the journal todayScientific reportsThe study used Canadian vaccine data collected from people living in long-term care and front-line health care workers working in long-term care and hospitals.

Looking at the group as a whole, the median duration of the antibody half-life of the immune response was 63 days for the primary series and increased to 115 days for those who received their booster shot, a statistically significant finding, says Korosec.

Evidence has shown that age can influence how well the body mounts an immune response after vaccinations, so much so that advanced age itself is considered a comorbidity, says Korosec.

"Chronological age is your time since birth. But you also have an immunological age, which correlates with your chronological age and is related to how your body loses its ability to defend itself against invading pathogens and produce antibodies over time," explains Korosec. “The funny thing is that as we get older, we also become more likely to develop diseases that can affect the immune system in counterintuitive ways.”

When studying this aspect, the researchers found that although older adults had a less long-lasting immune response, once they controlled other comorbidities such as high blood pressure, lung disease and cancer, age no longer had as much of an impact on the immune response.

Other interesting findings include a small but statistically significant immune response in men compared to women, as well as in people with asthma, who have a longer-lasting immune response - in fact, longer-lived than those with hybrid immunity from vaccinations and contracting COVID-19.

“We found that some results were surprising and worthy of further study, but of course we are not advocating that any particular comorbidity is beneficial,” Dick says. “We have no information from this study about how, for example, asthma would affect the severity of COVID-19 disease.”

Aside from the rigorous findings, the researchers also note that the study highlights the importance of interdisciplinary research and are excited about the opportunities for collaboration, with York's medical school scheduled to open in 2028.

“While we all come from math and statistics departments, the data comes from clinicians who graduated from medical school and are now professors of immunology, and I think this study shows how people with different skills can come together and do really interesting science.” says Korosec.

Moyles added: "We have a really world-class applied mathematics program at York, and now the university has announced a medical school. Imagine if these clinicians were in York and we had access to the data on the ground floor. This would shorten the research period many times over." years and has great potential for future interdisciplinary research at the university.”

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