A review of measles supplementary immunization activities and the implications for Pacific Island countries and territories

ABSTRACT

Introduction: Standard measles control strategies include achieving high levels of measles vaccine coverage using routine delivery systems, supplemented by mass immunization campaigns as needed to close population immunity gaps.

Areas covered: This review looks at how supplementary immunization activities (SIAs) have contributed to measles control globally, and asks whether such a strategy has a place in Pacific Islands today.

Expert commentary: Very high coverage with two doses of measles vaccine seems to be the optimal strategy for controlling measles. By 2015, all but two Pacific Islands had introduced a second dose in the routine schedule; however, a number of countries have not yet reached high coverage with their second dose. The literature and the country reviews reported here suggest that a high coverage SIA combined with one dose of measles vaccine given in the routine system will also do the job. The arguments for and against the use of SIAs are complex, but it is clear that to be effective, SIAs need to be well designed to meet specific needs, must be carried out effectively and safely with very high coverage, and should, when possible, carry with them other public health interventions to make them even more cost-effective.

KEYWORDS:

• Supplementary immunization activities
• outbreak
• surveillance
• acute fever and rash (AFR)
• routine immunization services
• susceptible
• measles-containing vaccine
• population immunity
• vaccine efficacy
• Pacific Island Countries and Territories

Acknowledgments

The authors wish to acknowledge the valuable assistance of Stewart Tyson, Will Schluter and Prakash Valiakolleri in compiling the data for this article. We also acknowledge the tremendous contribution of DFAT and national staff throughout the PICTs in generously supporting our efforts to document the situation in their countries.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

CJ Clements received financial support from the Department of Foreign Affairs and Trade (DFAT) while collecting data for this article. N Sadr-Azodi and TS Soakai received salaries from UNICEF and Secretariat of the Pacific Community, respectively.