Age-related immune response to measles virus in staff of a large city hospital

Abstract

The aims of the study were to examine age-related features of immune response to measles virus in staff of a large city hospital and to define groups at risk for measles outbreaks.Methods. The study involved 1,855 staff members of a large city hospital aged ≥ 19 years old who had documented vaccination against measles or a history of measles. The participants were divided into age groups with 5-year intervals starting from 19 years of age; there were 11 groups in total. The immune response to measles virus was measured in sera by ELISA using Vector-Best IgG-Kor test system (Russia).Results. Young employers of 19 to 23 years of age were most susceptible to measles; protective antibody level was not detected in 38.5% of them. They were followed by young-to-middle-aged workers (24 to 48 years old) who were negative for anti-measles antibodies or had non-protective level of antibodies in 16.7% to 27.5%. The anti-measles antibody level was low (42.3 % to 60.0 %) in employers of 19 to 43 years of age and gradually increased to 46.3% – 92.2% in the group of 44 to 68 years old.Conclusion. Herd immunity against measles in employers of a large city hospital did not meet requirements for successful infection control which implicates ≤ 7% of seronegative individuals. This means that measles outbreak could occur at any time because the proportion of seronegative individuals (11.5%) twice exceeded the cut-off value; the antibody level was controversial in 3.2% of individuals. Therefore, monitoring anti-measles antibody level in hospital staff is necessary to detect groups at risk who should be vaccinated against measles.

Gender Differences in the Level of Antibodies to Measles Virus in Adults

“…Decrease in the measles-specific antibody levels and registration of a large proportion of seronegative to measles virus among young men and women under 39 years old (24 [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]% and 28 [23][24][25][26][27][28][29][30][31][32][33][34]%, respectively) does not mean a complete loss of measles immunity, since the response of memory B-cells can quickly increase the synthesis of protective antibodies [27]; however, from our point of view, this does not exclude the patient's susceptibility to measles with the development of the clinical presentation of the disease.…”

“…At the age of 60 and older, in contrast, the level of antibodies is higher among women in comparison with men. It should be noted that with an age of 60 years and older, the proportion of people with low antibody levels decreases and the proportion of people with average levels of antibodies to measles virus increases among both sexes [ 30 ]. Of course, the revealed fact may be associated with the measles disease before the era of measles vaccination, although vaccination of people who have had atypical forms of the disease cannot be ruled out.…”

Characteristics of Anti-Measles Immunity in Lung Transplant Candidates

“…According to foreign authors, herd immunity rates ranges between 84.6% and 89.9%, also with a predominance of seronegative individuals in young adults [ 25 , 26 , 27 ]. Even among healthcare providers, the proportion of individuals with seronegative or equivocal anti-measles antibody levels ranges between 14.6% and 37%, reaching 38.5–70% in some age groups [ 18 , 19 , 28 ]. In a study conducted by T.G.…”

The Combination Vaccine against Measles

“…При изучении популяционного иммунитета выявляются возрастные особенности иммунитета к вирусу кори. Так, в недавнем исследовании, проведенном в крупном больничном комплексе мегаполиса с целью оценки коллективного иммунитета, было установлено, что наиболее восприимчивы к кори молодые сотрудники 19-23 лет, 38,5% которых были серонегативны [3]. За ними следовали работники молодого и среднего возраста (24-48 лет), в этой возрастной группе доля лиц серонегативных и с уровнем антител ниже защитного к вирусу кори была в пределах 27,5% -16,7.…”

“…За ними следовали работники молодого и среднего возраста (24-48 лет), в этой возрастной группе доля лиц серонегативных и с уровнем антител ниже защитного к вирусу кори была в пределах 27,5% -16,7. В возрастном интервале от 19 до 43 лет регистрировалось большее количество сывороток с низкими значениями уровня антител (от 60,0% до 42,3%), а в группах от 44 лет до 68 лет -напротив, возрастала доля лиц с средним значением уровня антител от 46,3% до 92,2%.Следовавтельно, коллективный иммунитет к вирусу кори у сотрудников крупного больничного комплекса мегаполиса не соответствует нормативному уровню (допускается 7% серонегативных лиц к кори), обеспечивающему благополучную эпидемическую ситуацию по кори, то есть в любой момент может возникнуть очаг инфекции за счет серонегативного контингента, количество которого выше нормы в 2 раза -11,5% (серонегативных) и 3,2% (титр антител ниже защитного) [3].…”