Analyzing features of measles immune response in adult patients

Abstract

Measles is a highly contagious, vaccine-preventable anthroponotic infection. Despite the policy of active measles vaccination for entire global population, measles has not completely disappeared, it wanes and waxes in outbreaks. It has been shown that not only the unvaccinated but also the vaccinated, which is quite understandable, subjects are involved in measles progression. The study was aimed at assessing features of the immune response in adult measles patients at rise in disease incidence upon its eradication. 1.158 blood sera from measles patients aged 18 to 70 living in Moscow and the Moscow region were studied by ELISA (Euroimmun, Germany). The vast majority of subjects were aged 1840 years comprising 72.36% cases. 69 sera collected at a later timepoint (1020 days from rash onset) were excluded and analyzed separately. According to anti-measles IgG and avidity level, the data were stratified as follows: group 1 with a primary type of immune response 582 sera (53.44%), not vaccinated in childhood; group 2 (secondary response) 446 sera (40.96%), vaccinated in childhood, but lost anti-measles antibodies; group 3 with intermediate level of parameters 61 sera. To clarify the type of immune response in group 3, an additional analysis of the spectrum of anti-measles antibody subclasses was carried out. It was shown that a mixed type of response was detected in this group: 31 subjects mainly had primary immune response, and 30 subjects secondary immune response. At the same time, 40 out of 61 subjects were vaccinated against measles 13 months prior to disease onset, i.e., it was overlapped on arising post-vaccination immunity. Thus, the previously identified trend towards the loss of post-vaccination immunity among older schoolchildren and young adults vaccinated in childhood who are involved in the epidemic process continues to worsen.