Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality

Area of Science:

• Immunology
• Epidemiology
• Public Health

Background:

• Measles is known to cause short-term immunosuppression, increasing susceptibility to secondary infections.
• The duration and long-term impact of measles-induced immune suppression on overall mortality remain incompletely understood.

Purpose of the Study:

• To investigate the prolonged effects of measles on host resistance and mortality from other infectious diseases.
• To determine if measles incidence is linked to non-measles infectious disease mortality over extended periods.

Main Methods:

• Analysis of population-level data from high-income countries, examining measles incidence and non-measles infectious disease mortality.
• Statistical coupling analysis to assess the relationship between measles incidence and mortality at a 2-3 year lag, across pre- and post-vaccine eras.

Main Results:

• Measles has a prolonged immunosuppressive effect on host resistance, lasting 2 to 3 years.
• Non-measles infectious disease mortality in high-income countries is significantly correlated with measles incidence at this extended lag.
• This association was observed in both the pre-vaccine and post-vaccine eras, indicating a persistent effect.

Conclusions:

• Long-term immunologic sequelae of measles, including lymphocyte depletion, drive interannual fluctuations in non-measles deaths.
• Measles vaccination provides long-term benefits by preventing measles-associated immune memory loss, thereby protecting polymicrobial herd immunity.
• These findings underscore the critical role of measles vaccination in maintaining population-level resistance to a wide range of infectious diseases.