Longitudinal study to common vaccines

Goal: To understand the longevity of humoral immune protection and the role played by memory B cells after common vaccinations. To quantify the heterogeneity in antibody responses to different vaccines and viruses. To quantify the time to loss of protective immunity to each vaccine or virus at the population level. Methods: Performed longitudinal data analysis on antibody titers for viral antigens (vaccinia, measles, mumps, rubella, varicella-zoster virus, and Epstein-Barr virus) and nonreplicating antigens (tetanus and diphtheria) in 45 subjects for a period of up to 26 years. Used a mixed-effects modeling framework to characterize the heterogeneity in antibody responses and to determine how variation in the magnitude and decay rate affect how protective immunity is lost at the population level to different virus and vaccine antigens. Results: Antiviral antibody responses were remarkably stable, with half-lives ranging from an estimated 50 years for varicella-zoster virus to more than 200 years for other viruses such as measles and mumps. Antibody responses against tetanus and diphtheria antigens waned more quickly, with estimated half-lives of 11 years and 19 years, respectively. B-cell memory was long-lived, but there was no significant correlation between peripheral memory B-cell numbers and antibody levels for five of the eight antigens tested. The statistical analysis and models helped to stratify the heterogenity factors and quantified each in a single plot to view interplays of factors, such as the fast-decay of anti-nonreplicating-antigens is compensated for by the higher magnitude of responses (relative to the level for protection) which explains a higher fraction of vaccinated individuals have protective immunity to tetanus and diphtheria than to measles, rubella, and vaccinia in the first 4 decades, suggesting the need for reevaluation of their boosting schedules.