Detection of serum antibodies against measles, mumps and rubella after primary measles, mumps and rubella vaccination in children.

Wednesday, 11th of December 2013

[source]Archives of Iranian Medicine[|source]

It has been estimated that even in countries where vaccination coverage approaches > 80%, a single dose of the vaccine leaves many children susceptible to measles. To eradicate measles and thus prevent mortality and morbidity associated with this highly infectious disease, the WHO recommends universal immunization of all children with two doses of measles vaccine. Needless to add that although the measles vaccine provides a high degree of protection, outbreaks continue to be reported in vaccinated children, with attribution going to multiple factors. Therefore, sero-surveillance for measles could be an additional intervention for vaccine efficacy monitoring and definition of the need and timing for supplemental immunizations.

In this article, the authors conducted this study to determine the efficacy of the MMR vaccine by testing IgM and IgG antibody levels at 4 – 7 weeks after first vaccine dose was administered to children. The report documents that 25% of 12-month-old children had IgM and IgG antibody levels below the protective levels for measles and rubella at 4 – 7 weeks after primary vaccination with MMR. The report concludes that it is necessary to give the second MMR dose soon after the first dose and preferably not later than 18 months of age. More details on this simple but yet policy informative study are available at:  http://www.ams.ac.ir/AIM/NEWPUB/13/16/1/0012.pdf

 

Abstract

In Iran, the measles, mumps and rubella vaccine (MMR) is administered in a two-dose protocol where the first dose is scheduled at 12 months of age. This study aims to determine the efficacy of the MMR vaccine by testing IgM and IgG antibody levels 4 - 7 weeks after primary vaccination.

METHODS: A single group cohort study was performed on healthy children, 12 - 15 months of age, who were vaccinated at health centers affiliated with Shahid Beheshti University of Medical Sciences in Tehran, from January to April 2009. Children with negative vaccination and/or clinical history for measles, mumps or rubella were administered the first dose of the MMR live attenuated vaccine. IgG and IgM antibodies were checked by enzyme linked immunoassay (ELISA) in serum samples 4 - 7 weeks after vaccination. A child was considered seropositive if antibody levels were higher than the assay cut-off level set by the ELISA kit.

RESULTS: Samples from 240 children were checked for antibodies against measles and rubella. Measles serum IgM level was positive in 71.7% of samples and IgG in 75.8%. The rubella serum IgM level was positive in 71.7% of children and IgG in 73.8%. From 190 blood samples that were checked for mumps antibodies, serum IgM was positive in 68.9% and IgG in 95.3%. No significant relationship was found between seropositivity and age or gender.

CONCLUSION: IgG and IgM antibody levels were below the assay cut-off levels against measles and rubella in approximately one-fourth of the children following primary MMR vaccination. A second dose was necessary to raise the level of protection against measles and rubella.