A team of researchers from Guinea-Bissau, Africa conducted a study to find out whether early measles vaccination can alter the immune system to improve the chances of survival if measles are contracted. The results of this study were published in BMC Public Health.
Measles vaccine and non-specific effects
New research has shown that vaccines may affect the overall disease rate and death rate by training the immune system in the body. It has also been shown that early measles vaccination and other recommended vaccines may have some non-specific effects that can change an individual’s susceptibility to a non-targeted disease. The World Health Organization (WHO) conducted a study for the evidence of non-specific effects of the Bacillus Calmette-Guérin vaccine, diphtheria-tetanus-pertussis vaccine, and measles vaccine. The measles vaccine review showed non-specific effects of the measles vaccine.
The current vaccination programs and policies do not consider the non-specific effects of a vaccine. WHO has recommended administering the measles vaccine at 9 months of age in countries with a high prevalence of measles, and administering it at 12 months of age where the measles infection is under control.
The research compared early measles vaccinations starting at age 4.5 months to the routine measles vaccine at 9 months with the standard dose of the measles vaccine at nine months of age. The study followed up with children under the age of 5 through a Health and Demographic Surveillance System in Guinea-Bissau. Children between 6 to 36 months with a vaccination card inspected were followed to the next visit or for a maximum of 6 months.
The results of the study showed that early measles vaccination lowers the death rate. However, giving the vaccine is only recommended under special circumstances in order to prevent interference from maternal measles antibodies (MatAb) on natural antibody response to the measles vaccine. Though the natural antibody response gets reduced, the vaccine still given in the presence of MatAb prevents severe cases and death from measles.
Measles vaccination increases survival
The study concluded that measles-vaccinated children had a better rate of survival as compared to measles-unvaccinated children. The most beneficial effects are for early measles vaccination children. As assumed from the beneficial effects of the measles vaccine, the current vaccination policy of increasing the age of vaccination when measles control improves may not actually help the measles vaccine reduce death rates due to measles. The benefits of the measles vaccine and the categorical age effects should be considered while planning vaccination programs in low-income countries.
Reference
Hansen JS, Thysen SM, Rodrigues A, Martins C, Fisker AB. Is early measles vaccination associated with stronger survival benefits than later measles vaccination?. BMC Public Health. 2018;18(1):984. Published 2018 Aug 7. doi:10.1186/s12889-018-5866-y
