Intensity of the immunity against measles in employees of the maternity unit in Moscow

Introduction. Measles remains an urgent problem in Russian healthcare. Despite the ongoing vaccination, there is an increase in the incidence of measles. Prevention of measles is particularly important in high-risk groups, as well as among healthcare professionals to prevent hospital-acquired outbreaks of infection. The duration of post-vaccination immunity during the elimination of measles has not been sufficiently studied, so often people who  have had measles in childhood or have 1–2 vaccinations against the disease lose their protective antibodies with age in the absence of natural boosterization. Goals and objectives. To study the intensity of specific immunity to measles in employees of the maternity unit. Material and methods. The study involved 271 employees of the maternity unit aged 21 to 93 years (262 serum samples). The level of IgG antibodies (Ab) to the measles virus in the blood serum was studied by ELISA using a standard set of reagents for the quantitative determination of IgG by «VECTOR-BEST». The result was  considered negative if the concentration of IgG to the measles virus in tested sample was ≤ 0.18 IU/ml and  positive – if 0.18 IU/ml.  Results. The number of seronegatives ranged from 0% to 30.8% in female employees with its maximum at age of 31–35 years. The lowest proportion of seronegative and the highest proportion of seropositive women were observed among the elderly, 60 years. Discussion. There is a marked tendency for an increase of the proportion of persons with average Ab levels with age and a decrease of the proportion of persons with low Ab levels. The percentage of seronegative women among employees exceeded the recommended level, which makes it possible for an nosocomial outbreak when an infection is introduced. Conclusion. The authors recommend that serological testing for the intensity of the immune response against measles should be included in the standard of the pre-vaccination screening for adults.