Do the Dynamics of Vaccine Programs Improve the Full Immunization of Children under the Age of Five in Cameroon?

"Raising the awareness of populations to health and immunization usually goes through communication channels such as the radio, television, newspapers. This is the reason why being exposed to these means of communication could be advantageous to the susceptibility of the child to be fully immunized."

Research has highlighted the significant differences between countries and localities in the sources of inequalities in child immunisation due to variations in structural, cultural, and institutional settings. In response to these discriminatory factors, countries like Cameroon have implemented specific immunisation promotion strategies to ensure children's full vaccination. This paper first examines the determinants of complete immunisation of children aged 12 to 59 months in Cameroon using logistic regression. It then breaks down the differences in probability of full immunisation coverage between 2 study periods: into a part attributable to differences in observed characteristics, on the one hand, and an unexplained component that may reflect organisational differences in terms of the administrative and financial aspects of the Expanded Program on Immunization (EPI).

As the researchers explain, the EPI started in Cameroon in 1976 and has since concentrated its activities around immunisation incentive programmes designed to achieve objectives pertaining to membership to the Global Immunization Vision and Strategy (GIVS). Since the creation of a central body under the supervision of the Ministry of Public Health, the immunisation of children has been organised as a service delivery strategy (described in the article) and additional immunisation accompanied by a communication system. The latter involves advocacy, social mobilisation, and communication for behaviour change.

To this end, a team of 3 people has been set up in each region to ensure communication for immunisation. Local mobilisers undertake communication activities for behaviour change by going from door to door to disseminate messages about immunisation. Also: town criers use megaphones, or mobile amplified sound systems, to spread the word; announcements are made in churches, mosques, schools, and meeting places; and commercials and micro-programmes are broadcast on rural and community radio stations. These activities are often held over the course of mass immunisation campaigns, though they are also designed to raise awareness about routine immunisation.

The researchers explain that, because the communication component for behaviour change rarely benefits from specific funding (partners only fund specific items such as the purchase of vaccines and immunisation equipment), communication focal points and local mobilisers present in the vast majority of health districts and areas have only been active during supplementary immunisation activities (SIAs).

This study draws on data from Demographic and Health Surveys (DHS) of 1991, 1998, 2004, and 2011 carried out by the National Institute of Statistics (NIS). The module concerning EPI vaccines was administered to 3,350, 2,317, 8,125, and 25,524 children under the age of 5 in 1991, 1998, 2004, and 2011, respectively. (See the article for the full methodology used.)

In general, children with a vaccination card are more than 7 times likely to be fully immunised than their counterparts who do not have one. This result was higher in 1991 and lowest in 2011. The results also show that the probability for the child to be fully immunised decreases with an increase in birth order. Furthermore, full immunisation has decreased by 29% - with 43% in 1998, 21% in 2004, and 32% in 2011 - for children whose mothers belong to reformist religions, including Islam, which have a penchant to preferring miracles through prayers. On the other hand, not belonging to any religion has increased the likelihood of full immunisation.

Notably, the contributions of EPI partners in terms of immunisation support as well as strategies to promote immunisation through communication for development were found to be of particular importance in increasing immunisation coverage. The study found that these activities significantly explain 67.62% of the 0.105 gain recorded within the 2011–2004 period and 72.46% of the 0.069 gain recorded within the 2004-1998 period. Among the possible contextual factors: At the community level, the liberalisation of the press at the beginning of the 1990s saw a rise toward the end of that decade of many community radio stations, which are close to the population and enable the conveyance of information on vaccination campaigns.

In conclusion: "This study evaluated the effect of immunization programs on the probability of children to be fully immunized and has found that the difference in the likelihood of full immunization between periods is mostly explained by the contribution of partners (GAVI, UNICEF, WHO, etc.) supporting immunization as well as strategies to promote immunization."