Measles and rubella serosusceptibity among population vaccinated with different schedules: the potential impact on measles-rubella elimination in Iran

Abstract

Background Iranian children were vaccinated with the scheduled two doses of monovalent measles vaccine (mMV) from 1984. In December 2003, a nationwide campaign of measles-rubella (MR) immunization was established to vaccinate 5–25 year- old individuals. In 2004, the mMV was replaced with measles- mumps- rubella (MMR) vaccine. Despite the high vaccination coverage, the outbreaks of measles still occur in the country. In this Study, the MR immunity status of various age groups, vaccinated with different schedules was investigated, and the immunologic response of seronegative subjects to revaccination was examined. Methods This cross-sectional study was conducted among 7–33-year-old healthy individuals with a documented history of measles vaccination from November 2017 to June 2018. The subjects were categorized as follows: group A, including 20–33 year-old individuals; vaccinated with 1–2 doses of mMV at ages 9 and 15 months, and revaccinated with MR, group B, including 15–19-year-old individuals, vaccinated with two doses of mMV at 9 and 15 months of age, and received additional dose of MMR upon school entrance, group C, including 11–14 year-old individuals, vaccinated with two-doses of MMR at the ages of 15 months and 6 years, and group D, including 7–10 year-old individuals vaccinated with two-doses of MMR vaccine at the ages 12 and 18 months, respectively. Levels of antimeasles- antirubella IgG antibodies in the collected sera were measured. Also antimeasles- antirubella IgM and IgG of seronegative individuals were reexamined at 4–6 weeks after MMR revaccination. The collected data were analyzed using descriptive statistical methods. Results A total of 635 individuals were investigated in this study. Group A, 98; group B, 295; group C, 139; and group D, 103 persons. Overall, 12.3 and 18.4% of the population were seronegative for measles and rubella antibodies. This rate varied greatly between the 4 groups: group A, 0/0–2%; group B,15.2–25.0%; group C,11.5–17.2%; and groupD,14.6–18.4%. After revaccination, 92 and 94.9% of seronegative individuals showed IgG response to measles and rubella vaccines, respectively. Conclusion Despite the high coverage rate of M-R containing vaccines, a significant number of vaccinated subjects were seronegative for measles and rubella, possibly because of secondary vaccine failure; this may negatively affect measles-rubella elimination targets in the country. If these findings are confirmed in similar future studies, a more robust regional/national supplementary immunization activity will be considered.

Serosurvey of anti‐rubella and anti‐measles IgG antibodies in young females in Jahrom, southern west Iran in 2012: A review of literature of the serological profile in Iran

“…However, a significant portion of vaccine recipients were seronegative for measles and rubella despite the high coverage rate of measles and rubella vaccinations, which may be due to secondary vaccine failure and may have a negative impact on the nation's goals for measles‐rubella eradication. Therefore, more substantial regional or national supplementary immunization program has to be taken into consideration if these findings are supported by similar future studies 20 …”

“…Therefore, more substantial regional or national supplementary immunization program has to be taken into consideration if these findings are supported by similar future studies. 20 The prime intention of current study was to monitor the impact of the public vaccination program against rubella and measles in women of childbearing ages in order to find out whether is essential to impose a new healthcare policy for extra inoculation in this target group or simply sustain the former program. We evaluated the efficacy of our vaccination program based on the seroprevalence of measles and rubella in our study location, which has been widely used in literature.…”

“…Therefore, more substantial regional or national supplementary immunization program has to be taken into consideration if these findings are supported by similar future studies. 20 …”

Seroprevalence of Measles and Rubella IgG Antibodies in Children and Pregnant Women in Iran

“…In Iran, adhering to Ministry of Health guidelines, a comprehensive program administered combined MMR vaccines to 95% of individuals aged 2 -25 years. In conjunction with meeting other WHO criteria, this places Iran on track to achieve Measles and Rubella elimination (14).…”