Measles Supplemental Immunization Activities (SIAs)

The Regional strategy for measles control recommends that a second opportunity for measles immunization be provided to all children irrespective of their vaccination status or history of clinical measles. The preferred method of provision of a second opportunity is through Supplemental Immunization Activities (SIAs) targeting children 9 months to 14 years in catch-up campaigns and 9 months to 4 or 5 years during periodic follow-up campaigns.

As of December 2008, all countries in the region (except Algeria, Seychelles and Mauritius) have completed their catch-up SIAs. Seven countries in the Southern African subregion (South Africa, Zimbabwe, Namibia, Botswana, Lesotho, Swaziland, Malawi) conducted catch-up SIAs between 1997 - 2000. The remaining 36 countries had their catch-up SIAs following the adoption of a Regional goal of measles mortality reduction in 2001. Between 2001 and 2008, 35 countries have had one catch-up SIAs totally reaching 236.7 million children.

All countries are now following up with periodic SIAs (follow-up SIAs) in order to prevent the accumulation of susceptibles in the inter-campaign interval. The periodicity of these campaigns is determined by the routine EPI coverage, the coverage during catch-up SIAs and the results of measles surveillance.

Between 2001 and August 2009, 39 countries have conducted at least one follow-up Supplemental Immunization Activities (SIAs), reaching over 175.8 million children. In 2008 alone, follow-up SIAs were implemented in 11 countries targeting a total of 66.9 million children, while in 2009, 18 countries have planned follow up SIAs targeting 31 million children.

In order to better guide countries in their preparations and implementation of measles SIAs, WHO AFRO has developed generic guidelines.

Measles SIAs have provided an opportunity for supplying additional health interventions such as the administration of Vitamin A and de-worming tablets to children under 5 years of age, tetanus toxoid vaccination of women of child-bearing age, and distribution of Insecticide Treated Nets (ITNs) for the prevention of malaria in children and pregnant mothers. These interventions have been integrated with synergistic results and attaining the desired goals in almost all countries (see table - pdf 6.2kB).

Measles SIAs have also contributed to efforts to strengthen health systems by forging and strengthening local partnerships, improving the cold chain systems, promoting and building capacity for injection safety, strengthening disease surveillance systems and promoting the use of surveillance data for program management.

WHO/AFRO Measles SIAs Field Guide [pdf 784kB]

WHO/AFRO Measles SIAs Evaluation Guidelines [pdf 223kB]