Risk factors for measles death: Kyegegwa District, western Uganda, February–September, 2015
Vaccination against measles has substantially decreased child mortality worldwide. The recent introduction of varicella immunization has significantly reduced the associated disease burden. However, there exists a period of elevated disease susceptibility among infants secondary to the diminishment of maternal passive immunity. This article reviews recent studies on transplacentally transferred antibodies against measles and varicella. Recent Findings Both MMR and varicella vaccines are usually administered in children, aged older than 12 months, since it has been established that co-existing maternal antibodies interfere with vaccine immunogenicity. Currently, a notable proportion of infants are susceptible to measles due to the diminishment of transplacentally acquired passive immunity. The most plausible explanations of this phenomenon include the replacement of the reproductive population by vaccinated women, as opposed to those having undergone natural measles infection, and the decrease of natural boosting effect of the wild type virus. Summary The window of susceptibility to measles has increased in infants, as it might also happen for varicella in the near future. In order to progress towards the diseases’ eradication and, more importantly, to protect those population groups, including young infants, with high morbidity rates attributed to the diseases, it is evident that further investigation will be conducted for the immunization against measles and varicella at an earlier age.