Pentavalent DTP-Hib-HBV vaccine(BioNet-Asia Co. Ltd.)

Estimates of WHO and UNICEF vaccination coverage may provide little insight into the extent to which vaccinations are administered on time. Yet, lack of adherence to the recommended age to receive a specific vaccination may have detrimental health consequences. For example, delays in receiving vaccination will prolong the risk of lack of protection, often when disease risk is highest, such as during early infancy. We estimated the reported age at vaccination, and vaccine coverage at different ages in children from five sub-Saharan African countries.

We analyzed data from the latest Demographic and Health Programme databases available for Burkina Faso 2010 (n=15,044 observations), Ghana 2008 (n=2992), Kenya 2008-9 (n=6079), Senegal 2010-11 (n=12,326), and Tanzania 2010 (n=8023). We assessed, amongst vaccinees, the exact age when vaccine was administered for the three infant doses of pentavalent vaccine (DTP) and the first dose of measles-containing-vaccine (MCV), as well as the proportion of children immunized with these antigens by a certain age. Vitamin A supplementation (VAS) coverage was evaluated as a potential contact visit for vaccine introduction.

For all DTP doses, the median intervals between recommended and actual ages of receiving vaccination ranged from 12, 17 and 23 days in Kenya, to 22, 33 and 45 days in Senegal. MCV was mostly given during the recommended age of 9 months. In each country, there was a large discrepancy in the median age at DTP vaccination between regions. VAS coverage in young children ranged from 30.3% in Kenya to 78.4% in Senegal, with large variations observed between areas within each study country.

In the context of new vaccine introduction, age of children at vaccination should be monitored to interpret data on vaccine-preventable disease burden, vaccine effectiveness, and vaccine safety, and to adapt targeted interventions and messages.

Hemophilus influenzae type b (Hib) is a leading cause of bacterial meningitis among infants and young children and the second leading cause of bacterial pneumonia deaths among children under 5 y. The overall case-fatality rate for Hib meningitis is 20-29%, and nearly 30% of surviving children suffer from major disabilities, while all invasive Hib disease (including meningitis) has a case fatality rate of 16% in India. Using the estimates from the Hib study, ~215,000 new cases of Hib pneumonia occur yearly in Indian children under the age of 5 y and result in over 61,000 deaths. This level of mortality is because of poor access to health services and poor health-seeking behavior by population, lack of laboratory infrastructure, and difficulty to diagnosis Hib disease among affected children. Disease burden is difficult to calculate. Even for those affected children who do reach healthcare facilities, the lack of quality health services and increasing prevalence of antibiotic-resistance makes treatment difficult for these children. Even in countries that have poor immunization coverage, indirect benefits of the Hib vaccine have been reported due to the herd effect. The Hib vaccine thus should be effective in India where Universal Immunization Programme (UIP) coverage is poor. Following the World Health Organization (WHO) recommendation that Hib-containing Pentavalent DTP vaccine (a combination vaccine that protects against five killer diseases: diphtheria, pertussis, tetanus, hepatitis B [hepB] and Hib) should be administered to every child in the world, the Government of India asked the National Technical Advisory Group on Immunization (NTAGI) to study the need for HepB and Hib vaccines in the Indian population. The India Ministry of Health and Family Welfare introduced Pentavalent DTP vaccines in the UIP with the aim of reducing the burden of Hib-related morbidity and mortality.