Mozambique’s Ministry of Health instituted an expanded immunization program in 1979, but by the early 2000s, full coverage rates remained low in many parts of the country. In 2002, researchers set out to understand the barriers standing in the way of improved coverage, from the attitudes of mothers and vaccine access, to interactions with healthcare workers.

A main objective was to determine what mothers knew about the subject. The study found that mothers’ knowledge was generally low. For example, a majority didn’t know key facts about vaccine-preventable diseases, or the ages at which a child should have completed various vaccinations. Further, many held misconceptions, such as whether it is safe to vaccinate a sick child; nearly a third thought it was not.

One might expect that this gap in knowledge would negatively affect uptake. But despite misconceptions and significant gaps in knowledge, mothers in Mozambique overwhelmingly perceived vaccination as important to a child’s health and actively sought out vaccines for their children. In fact, in an area where misperceptions were more widely held, coverage rates were actually higher. As the researchers found, “detailed knowledge about vaccine preventable disease is not necessary to create or maintain demand — study results show that knowledge is low while demand is high.”

The case highlights a common assumption: that there is a causal correlation between knowledge and behavior. Across studies, the relationship is usually more complicated. A study in the Gambia found that nearly half of rural mothers could not correctly name any vaccine-preventable diseases, yet still actively sought out vaccines (national coverage was 90%).* In the case of Mozambican mothers, the lack of a robust understanding also mattered little when it came to seeking out vaccinations.

Whereas practical knowledge about when, where and how to access vaccinations can matter greatly, knowledge about vaccine-preventable diseases and vaccines themselves are often less directly tied to immunization outcomes. Investing in the enhancement of knowledge alone won’t necessarily yield an increase in coverage.

Sources: Sheldon & Alons (2003), A study to describe barriers to childhood vaccination in Mozambique
* Leach (2008), Understandings of immunization: some West African perspectives