Persistence of measles, mumps, and rubella immunity following childhood vaccination in Australian health science students: a cohort study.

OBJECTIVE

This study aimed to determine the serological immunity status for measles, mumps, and rubella among university health science students, and to assess the association between childhood vaccination and adult immunity.

METHODS

A cohort study was conducted at a regional university in Queensland, Australia. Convenience sampling was used to evaluate long-term immunity through measles, mumps, and rubella IgG serology. Childhood immunisation records from the Australian Immunisation Register were reviewed. Data sources included retrospective chart audits (2020-2022) and prospective data collection from students attending the university health service (July 2023-May 2024). Participants were categorised into two birth cohorts: 1990-1999 and 2000-2009.

RESULTS

Among 331 students, international students demonstrated the highest seropositivity rates for all three viruses across both cohorts. Of those who tested seropositive for all three viruses (n = 89, 27 %), 40 % (n = 36) were domestic students, and 60 % (n = 53) were international students.

CONCLUSIONS

The standard two-dose measles, mumps, and rubella vaccine schedule may not confer lifelong immunity. Low measles immunity among students born between 1990 and 1999 and reduced rubella immunity in domestic students across both cohorts suggest waning immunity over time. The observed decline in immunity 10-15 years post-vaccination highlights the need for further investigation into the efficacy and public health value of a third MMR dose administered during adolescence or early adulthood.