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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-.

Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Mumps outbreaks in vaccinated populations: are available mumps vaccines effective enough to prevent outbreaks?

GH Dayan and S Rubin.

Review published: 2008.

Link to full article: [Journal publisher]

CRD summary

This review examined the effectiveness of one and two doses of different mumps vaccine strains on outbreaks of mumps in vaccinated populations. The authors concluded that more effective mumps vaccines were needed. Given the types of studies included, the reliability of their results is unknown, but the authors' broad conclusions appear to reflect the results.

Authors' objectives

To assess the effectiveness of one and two doses of different mumps vaccine strains, on outbreaks of mumps in vaccinated populations, and to assess factors that potentially have an impact on effectiveness.

Searching

PubMed and EMBASE were searched, and search terms were provided. The reference lists of relevant publications were also checked. No restrictions were placed on publication type, publication date, or language of publication.

Study selection

Studies that evaluated mumps outbreaks and that reported the proportion of mumps cases among vaccinated persons or that reported vaccine effectiveness were eligible for inclusion. Studies that reported rates of primary vaccine failure, and studies that evaluated antigen differences between mumps virus strains, were also eligible for inclusion. The latter type of study had to report neutralising antibody titres against different mumps virus strains in serum samples from vaccinated participants.

In the included studies, populations were vaccinated only with the Jeryl Lynn strain, or with multiple strains, including Jeryl Lynn, Urabe, Rubini, Toitsukabu, and Torii, or the vaccine strain was not reported. Studies of outbreaks in a number of different countries were evaluated. Most studies were in school or community settings.

The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.

Assessment of study quality

The authors did not state that they assessed validity.

Data extraction

The number of cases of mumps, and the proportions of participants who received one and two doses of vaccine were extracted from the studies. Information on time since vaccination was also extracted to assess the occurrence of waning immunity.

The authors did not state how many reviewers were involved in the data extraction process.

Methods of synthesis

A narrative synthesis was presented.

Results of the review

In the review there were 47 studies, describing 50 outbreaks and at least 54,300 mumps cases.

The highest proportion of mumps cases was among those vaccinated with the Rubini strain and the lowest was among those vaccinated with the Urabe strain. With the exception of one outbreak, the percentages of mumps cases were lower in those vaccinated with two doses of vaccine.

Vaccine effectiveness after one dose (23 studies) ranged from 73% to 91% for the Jeryl Lynn strain vaccine, 54% to 93% for the Urabe strain vaccine, and from -55% to 40% for the Rubini strain vaccine. The effectiveness of two doses (3 studies) was higher than one dose, but no statistical differences were reported.

Four studies reported that the time since vaccination was not associated with an increased risk of disease, and three studies reported that participants who were vaccinated more than five years before an outbreak were at increased risk of developing disease.

Mean rates of primary vaccine failure did not significantly differ for the Jeryl Lynn, RIT-4385, Urabe, and L-Zagreb vaccine strains (range: 5% to 9%).

Authors' conclusions

More effective mumps vaccines were needed as well as a review of current vaccination policies to prevent future outbreaks.

CRD commentary

This review addressed a clear question and presented broad inclusion criteria. Attempts were made to identify studies published in any language, which limits the potential for language bias. It does not appear that the authors searched for unpublished data, so some data may have been missed. The authors did not state how many reviewers were involved in selecting the studies, or in the data extraction process, so the risk of reviewer error and bias cannot be ruled out. The authors did not state that they assessed validity, but this may not be an issue for the types of studies evaluated. The studies were appropriately summarised using a narrative synthesis.

Given the types of studies included, and their methodological variation, the reliability of their results is unknown, but the authors' broad conclusions appear to reflect the results.

Implications of the review for practice and research

Practice: The authors stated that the evidence suggested that long-term prevention of mumps outbreaks using current vaccines and vaccination schedules may not be feasible.

Research: The authors stated that more research was required to develop more immunogenic and effective mumps vaccines, and to assess current vaccination policies.

Funding

National Vaccine Program Office.

Bibliographic details

Dayan GH, Rubin S. Mumps outbreaks in vaccinated populations: are available mumps vaccines effective enough to prevent outbreaks? Clinical Infectious Diseases 2008; 47(11): 1458-1467. [PubMed: 18959494]

Indexing Status

Subject indexing assigned by NLM

MeSH

Disease Outbreaks; Humans; Incidence; Mumps /epidemiology /immunology; Mumps Vaccine /administration & dosage /immunology; Rubulavirus /immunology /isolation & purification

AccessionNumber

12009101541

Database entry date

18/11/2009

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 18959494