Measles immunity gaps in an era of high vaccination coverage: A serology study from Taiwan
Journal
Travel Medicine and Infectious Disease
Journal Volume
36
Pages
101804
Date Issued
2020
Author(s)
Abstract
Background: Routine vaccination for children drastically reduces measles cases. Nonetheless, the global resurgence of measles since 2018 highlights the need for evaluating vaccine-induced immunity in an era of high vaccination coverage, especially in international travelers. This study aims to identify high-risk persons via analyzing the impact of age and different vaccination schedules on seroprevalence of measles in a country with high vaccination coverage, attempting to provide suggestions regarding pre-travel measles vaccination in highly immunized countries. Method: We retrospectively collected serological results of measles from Taiwanese travelers during 2008–2017 and middle-aged subjects from community during 2007–2009. Participants were classified by age groups and cohort based on the national immunization program: cohort I (pre-mass vaccination), cohort II (suboptimal measles vaccination), and cohort III (2-dose MMR in childhood). The effects of age group on seropositivity was shown by odds ratio (OR) with 95% confidence interval (CI) in a logistic regression model. Results: The overall measles seroprevalence was 74.5% (N = 1096, mean age = 31.7 ± 12.3 years), with adolescents having the lowest seropositivity (65.9%) and participants ?50 years having the highest (89.4%). Seropositivity was significantly higher in cohort I (pre-mass vaccination) compared with the other 2 cohorts (P < 0.0001). The effect of aging on seropositivity was only significant in cohort II (OR = 1.84, 95% CI = 1.13–2.99, P = 0.014 for 30–39 years vs. 20–29 years). Conclusions: Waning immunity to measles in adolescents and young adults is a dominant issue in highly vaccinated cohorts. Enhancing pre-travel vaccination against measles can effectively fill the immunity gaps in highly immunized countries. ? 2020
Other Subjects
adolescent; adult; aging; article; child; childhood; cohort analysis; controlled study; female; groups by age; human; immunity; major clinical study; male; mass immunization; measles vaccination; middle aged; preventive health service; retrospective study; serology; seroprevalence; Taiwan; travel; vaccination coverage; young adult; measles; seroepidemiology; Taiwan; vaccination; measles vaccine; virus antibody; Adolescent; Adult; Antibodies, Viral; Child; Humans; Measles; Measles Vaccine; Middle Aged; Retrospective Studies; Seroepidemiologic Studies; Taiwan; Vaccination; Vaccination Coverage; Young Adult
Publisher
Elsevier USA
Type
journal article