Study Finds Seasonal Patterns in Children's Vaccine Antibody Responses

A pooled analysis of 96 randomized controlled trials found that the time of year children received vaccines against polio, measles, chickenpox and other diseases was associated with differences in the strength of their antibody response. The study examined data from roughly 48,000 children across multiple countries and seasons.

Researchers excluded participants who already had antibodies to the target pathogens before vaccination.

In temperate zones of both hemispheres, antibody responses were generally stronger during winter months. Closer to the equator, the timing of peak responses varied by vaccine, with some showing larger seasonal swings than others. The pattern held after accounting for prior exposure, though the study did not identify the exact environmental or biological drivers.

"We found that there is indeed a seasonal immune response," said Laura Barrero Guevara of New York University. Cathy Wyse of the University of Edinburgh, who was not involved in the work, said the results suggest human immune function differs across seasons, similar to patterns observed in other species.

The researchers noted that differences in antibody levels do not necessarily mean differences in protection from disease, and they advised against delaying scheduled vaccinations to chase possible seasonal gains.