Christensen LD, Eriksen HB, Biering-Sørensen S, Balé C, Do VA, Andersen A, Martins CL, Sodemann M, Aaby P, Benn CS. 2014. The effect of early measles vaccination on thymic size. A randomized study from Guinea-Bissau. Vaccine. 2014 Mar 26;32(15):1641-4. doi: 10.1016/j.vaccine.2014.01.034. Epub 2014 Feb 9.
In low-income countries early measles vaccine (MV) is associated with reduced child mortality which cannot be explained by prevention of measles. A large thymus gland in infancy is also associated with reduced mortality. We hypothesized that early MV is associated with increased thymic size. Within a randomized trial providing MV at age 4.5 and 9 months or MV only at age 9 months, thymic size was assessed by ultrasound at age 4.5 months, before randomization to early MV or no early MV, and 4 weeks later. Among 656 children, there was no effect of early MV on thymic size, the geometric mean size ratio being 0.99 (95% CI: 0.96-1.02). In a post hoc analysis early MV was associated with a negative effect in healthy children but a positive effect in ill children. In conclusion, early MV at age 4.5 months had no overall effect on thymus size 4 weeks later. Trial registration: http://clinicaltrials.gov, NCT01486355.












Last revised 11 April 2014