Applying an equity lens in the Decade of Vaccines.

Addressing inequities in immunisation must be the main priority for the Decade of Vaccines. Children who remain unreached are those who need vaccination - and other health services - most. Reaching these children and other underserved target groups will require a reorientation of current approaches and resource allocation. At the country level, evidence-based and context-specific strategies must be developed to promote equity in ways that strengthen the system that facilitates vaccination, are sustainable and extend benefits across the life cycle. At the global level, more attention must go on ensuring sustainable and affordable supply for low- and middle-income countries to vaccine products that are appropriate for the contexts where needs are greatest. Finally, data must be disaggregated and used at all levels to monitor and guide progress to reach the unreached.

Global Immunization Vision and Strategy (GIVS): a mid-term analysis of progress in 50 countries.

Within the overall framework set out in the Global Immunization Vision and Strategy (GIVS) for the period 2006-2015, over 70 countries had developed comprehensive Multi-Year Plans (cMYPs) by 2008, outlining their plans for implementing the GIVS strategies and for attaining the GIVS Goals at the midpoint in 2010 or earlier. These goals are to: (1) reach ≥90% and ≥80% vaccination coverage at national and district level, respectively; and (2) reduce measles-related mortality by 90% compared with the 2000 level. Fifty cMYPs were analysed along the four strategic areas of the GIVS: (1) protecting more people in a changing world; (2) introducing new vaccines and technologies; (3) integrating immunization, other health interventions and surveillance in the health system context; and (4) immunizing in the context of global interdependence. By 2010, all 50 countries planned to have introduced hepatitis B (HepB) vaccine, 48 the Haemophilus influenzae type B (Hib) vaccine and only a few countries had firm plans to introduce pneumococcal or rotavirus vaccines. Countries seem to be inadequately prepared in terms of cold-chain requirements to deal with the expected increases in storage that will be required for vaccines, and in making provisions to establish a corresponding surveillance system for planned new vaccine introductions. Immunization contacts are used to deliver other health interventions, especially in the countries in the World Health Organization (WHO) Africa Region. The cost for the planned immunization activities will double to U$27 per infant, of which U$5 per infant is the expected shortfall. Global Alliance for Vaccines and Immunization (GAVI) funding is becoming the largest contributor to immunization programmes.

Economic analysis of the 1996-1997 mass measles immunization campaigns in South Africa.

To evaluate economic implications of conducting a "catch-up" measles vaccination campaign, we conducted an economic analysis of the 1996-1997 measles immunization campaign in two provinces of South Africa comparing the baseline two-dose routine immunization program to the combined vaccination strategy (routine two-dose immunization program, plus the 1996-1997 campaign). The study findings indicate that the 1996-1997 mass measles immunization campaign was cost-effective in both study provinces, and cost-saving in the province with higher pre-campaign disease incidence and lower routine vaccination coverage. An early investment in effective vaccination strategies that rapidly reduce disease burden apparently results in better returns, both epidemiologically and economically.

Molecular epidemiology of measles virus in Kenya.

Measles causes significant morbidity and mortality globally. Many countries have embarked on immunization programs to control and prevent measles outbreaks and eventually to eliminate endemic measles. Kenya is currently in the outbreak control and prevention stage for measles. Measles virus genotyping is important for molecular epidemiological purposes, including the documentation of the elimination of endemic measles virus strains from a country, and mapping of transmission pathways. In this study, we collected clinical specimens from measles outbreak cases in 2002 in Kenya for measles virus genotyping. We were able to isolate and/or detect measles virus in 10 cases from 5 of the 8 provinces in Kenya. All these Kenyan measles strains were determined to be genotype D4 strains when compared to the standard World Health Organization-designated measles virus reference strains. Interestingly, the Kenyan D4 strains clustered into two distinct D4 subgroups. In addition, the inclusion of other published D4 measles strains in this analysis indicated that there are four distinct D4 clusterings, or subgroups: Montreal-like, India-like, Johannesburg-like, and Ethiopia-like. This is the first measles molecular epidemiology study in Kenya and establishes the current endemic measles strain as genotype D4. Importantly, this study shows that the Kenyan D4 strains are distinct from the B3 measles strain found in West Africa and the D4 strains reported in Ethiopia.

Impact of alternative approaches to accelerated measles control: experience in the African region, 1996-2002.

From 1996 to 2000, several African countries accelerated measles control by providing a second opportunity for measles vaccine through supplemental campaigns. Fifteen countries completed campaigns in children aged 9 months to 14 years. Seven countries completed campaigns in children aged 9-59 months. In almost all countries that conducted campaigns in children aged 9 months to 14 years, measles deaths were reduced to near zero. In six countries, near-zero measles mortality has been maintained for 4-6 years. Supplemental immunization in children <5 years old was only partially effective (range, 0-67%) in reducing mortality. Measles cases decreased by 50% when routine vaccination coverage increased from 50% to 80%. Initial measles campaigns in children aged 9 months to 14 years, follow-up campaigns in those aged 9-59 months every 3-5 years, and increased routine coverage to 80% will be needed to reduce and maintain measles deaths in African countries at near zero.

Impact of the 1996-1997 supplementary measles vaccination campaigns in South Africa.

BACKGROUND: In South Africa, as part of an effort to eliminate indigenous measles by 2002, vaccination campaigns were conducted in 1996-1997 targeting all children aged 9 months to 14 years; coverage was estimated at 85%. The impact of the campaigns on measles disease burden was evaluated in 1999. METHODS: We analysed routine measles surveillance data and undertook a retrospective review of hospital registers in two of South Africa's nine provinces. RESULTS: In Mpumalanga in the pre-campaign years (1992-1996), 4,498 measles cases and 6 deaths were reported; 182 cases and no deaths were reported in 1997-1998. Hospital registers showed 1,647 measles hospitalizations and 11 deaths in the pre-campaign period, and 60 hospitalizations and no deaths after the campaign (1997-April 1999). In Western Cape in pre-campaign years (1992-1997), 5,164 measles cases and 19 deaths were reported; 132 cases and no deaths were reported in 1998. Hospital registers showed 736 measles hospitalizations and 23 deaths in the pre-campaign period, and 29 measles hospitalizations and no deaths post-campaign (1998-July 1999). CONCLUSIONS: Study findings indicate that reported measles cases, measles-related hospitalizations and deaths were considerably reduced in both provinces after the campaign compared with the pre-campaign period. Longer observation is needed to evaluate the long-term impact of the campaigns.

First 5 years of measles elimination in southern Africa: 1996-2000.

BACKGROUND: Measles is the leading cause of vaccine-preventable death in Africa. Regional measles elimination is considered feasible using current vaccines and a series of WHO-recommended strategies. We aimed to interrupt transmission of measles, and to use case-based surveillance to show the effect of such interruption. METHODS: In southern Africa from 1996, seven countries with a total population of approximately 70 million and with relatively high routine vaccination coverage implemented measles elimination strategies. In addition to routine measles immunisation at 9 months of age, these included nationwide catch-up campaigns among children aged 9 months to 14 years, then follow-up campaigns every 3-4 years among children aged 9-59 months, and the establishment of case-based measles surveillance with serological diagnostic confirmation. RESULTS: Nearly 24 million children aged 9 months to 14 years were vaccinated, with overall vaccination coverage of 91%. Reported clinical measles cases declined from 60000 in 1996 to 117 laboratory-confirmed measles cases in 2000. Reported measles deaths declined from 166 in 1996 to zero in 2000. No increase in adverse events was noted after the measles vaccination campaign. CONCLUSION: A reduction in measles mortality and morbidity can be achieved in very low-income countries, in countries that split their vaccination campaigns by geographical area or by age-group of the target population, and where initial routine measles vaccination coverage among infants was <90%, even when prevalence of HIV/AIDS was extremely high. Continued high-level national commitment will be crucial to implementation and maintenance of proven strategies in southern Africa.