Thinking about getting a spring-time booster shot? A new study coming out of York University’s Centre for Disease Modelling in the Faculty of Science shows that immunity after a COVID-19 booster lasts much longer than the primary series alone. These findings are among other, sometimes “unintuitive,” revelations of how factors like age, sex and comorbidities do and don’t affect immune response. ooking at the group as a whole, the median length for the antibody half-life immune response was 63 days for the primary series, and increased to 115 days for those who went on to receive their boosters, a statistically significant finding, the researchers say.