COVID-19 Boosters Provide Nearly Double the Protection of Original Shots –

TORONTO— When it comes to long-lasting COVID immunity, new research from Canada suggests boosters are better than your original shot. Researchers from the University of York’s Center for Disease Modeling in the Faculty of Science report that immunity after a COVID-19 booster shot lasts much longer than just the primary series.

The research team behind this conclusion, York Postdoctoral fellows Chapin Korosec and David Dick, Professor of Applied Mathematics Iain Moyles, and University of New Brunswick Professor James Watmough, used health data submitted to the COVID Immunity Task-Force- project that includes more than 150 people who have received the Pfizer-BioNTech or Moderna COVID-19 vaccine. The study author’s main goal was to measure how immunity holds up over time.

“Our approach as mathematicians is to create mathematical models of the immune system and then calibrate those models with healthcare data to advance our understanding of the human immune system. It was very interesting to see that the booster dose of SARS-CoV-2 has such a dramatic increase in protective longevity compared to the primary two-dose series,” said Korosec, the study’s lead author, in a press release.

The study used Canadian vaccine data collected from individuals living in long-term care, in addition to frontline health care workers working in long-term care and hospitals. Among the group as a whole, the mean duration of immune response with antibody half-life was 63 days for the primary series – rising to 115 days for those who received a booster shot at a later date.

Research during the pandemic has shown that age can influence the extent to which a body can mount an immune response after vaccination. In fact, old age itself is considered a comorbidity, Korosec notes.

“Chronological age is your time since you were born. But you also have an immunological age, which is correlated with your chronological age, and which is related to the way your body loses its ability to defend itself against invading pathogens and produce antibodies as time goes on,” Korosec explains. “What’s complicated is that as we age chronologically, the likelihood of contracting diseases that can affect the immune system in non-intuitive ways also increases.”

Elderly woman receiving the COVID-19 vaccine
The mean duration of immune response with antibody half-life was 63 days for the primary series – increasing to 115 days for those who received a booster injection (© Rido –

Examining this aspect specifically, researchers found that older adults showed a less long-lasting immune response. Importantly, however, once researchers controlled for comorbidities (hypertension, lung disease, cancer, etc.), age no longer showed a significant impact on the immune response.

Additional notable findings include a small but still statistically significant immune response for men versus women. People with asthma also showed a longer-lasting immune response – more durable than people with hybrid immunity to vaccines and who contracted COVID-19.

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

In addition to the main findings, researchers also add their credits on the importance of interdisciplinary research. They are excited about the possibilities for future collaboration, with plans to open York’s medical school in 2028.

“Although we all come from the math and statistics departments, the data comes from doctors who have gone through medical school and are now professors studying immunology, and I think this research shows how people with different skills can come together and really can do interesting science. says Korosec.

“We have a really top applied mathematics program at York, and now the university has announced a medical school. Imagine if these doctors were in York and we had access to the ground floor data. This would shorten the research timeline by years and has enormous potential for future interdisciplinary research at the university,” concludes Prof. Moyles.

The research was published in Scientific reports.