Immunization Promotion Activities: Are They Effective in Encouraging Mothers to Immunize Their Children?

Introduction

This study was conducted to evaluate the effectiveness of the Mexican National Vaccination Council (CONAVA)'s communication activities for the Second National Health Week (SNHW) in Mexico City. The study sought to determine whether the messages communicated were effective in providing information to mothers and in motivating them to have their children vaccinated. The authors conclude that the SNHW campaign was effective and suggest that further formative study should be pursued to ensure that communications are culturally appropriate.

Key Findings

This study is set against the background of mass immunisation drives primarily oriented toward the eradication of polio. The authors believe that mass communication activities are an essential component of a successful vaccination campaign. Their goal is to look at how the communications used by CONAVA impacted the knowledge and actions of mothers in various social strata.

There are 4 main variables in the study that the authors sought to assess. The first is knowledge, defined as the mothers' information about the existence of the SNHW; respondents were also queried as to where they got this knowledge. The second variable is comprehension, the mothers' understanding of the received messages (e.g., regarding which vaccines were being promoted and any slogans or features of the campaign). These two variables were combined to gain a sense of the awareness on the part of mothers with regard to the SNHW. Respondents were grouped into three categories: "aware", "unaware", or "partly aware" - cases wherein mothers had been exposed to the campaign but were unsure of its purpose or confused it with some other health promotion initiative. The third variable evaluated was motivation, a measure of the behaviour of mothers after receiving SNHW messages, specifically, whether or not they took their children to be vaccinated. This was further assessed by determining whether mothers vaccinated their children as a result of the campaign messages or had to be invited personally by a health worker. The type of vaccine received and the location of the vaccination (clinic, health post, or home) were also recorded. The study also evaluated the mothers' opinion about the campaign messages, whether they liked them or not, and whether they considered them informative and persuasive. The independent variable was socioeconomic status, classed as upper, middle, or lower based on an index score taking into account several factors.

Of the total number of respondents (n=935), 64.3% were classified as "aware", 24% as "partly aware", and 11.75% as "unaware". There were some differences in awareness linked to the age of the mothers, with older mothers generally being more aware (knowledgeable mothers: aged 25 = 85.9%, aged 25-34 = 89.5%, aged >34 = 88.3%) and some differences resulting from the age and number of children.

The exploration into motivation required dividing the respondents into three groups based on their level of awareness, and then further dividing them based on whether or not they had had their children immunised during the SNWH. Among the group of "aware" mothers, 87.5% had had their children immunised, 72% of those had done so in response to promotion campaign messages, and 27.9% had done so after being invited. Of the total of the "aware" group, 12.5% of respondents did not seek any services. In the "partly aware" group, 83.9% of their children were immunised, though the percentage that did so purely as a result of the campaign messages fell to 63.8%. Among the "unaware" mothers the percentage that had their children vaccinated fell to 72.7%, a significant decline in rates.

Socioeconomic (SE) status was a strong determinant in the level of awareness of mothers. 76.9% of those in the upper socioeconomic category were "aware", versus 65.2% in the middle and 58.5% in the lower. However, it was the upper category that was the most likely not to seek immunisation (22.6%) while only 8.6% of the lowest strata refused service even after invitation. The authors suggest that this phenomenon is best explained by the prevalence of upper-income mothers taking their children to private medical clinics and facilities rather than taking advantage of the SNHW and its drives. Thus, a greater overall proportion of children from the middle and lower socioeconomic status strata received vaccines than did those in the upper strata.

The authors also note that health clinics (46.9%) and health posts (27.6%) were the most likely locations for the provision of services, with slight differences between various SE groups. Only 16.7% of the total received services in their homes, demonstrating an important shift towards active health-seeking behaviour on the part of mothers, and a move away from the passive and compulsory models of former campaigns.

The authors' main findings are that mass media promotion and popular campaigns are an effective strategy for informing and motivating mothers to seek immunisation services. Overall, 83% were aware of the campaign and 63% were impacted by its messages. The net increase in immunisation between the "aware" and "unaware" groups was 14.8%, though it must be recognised that a relatively large proportion of the "unaware" mothers also took their children for vaccinations, a feature the authors attribute to long-term momentum gained by successive vaccination campaigns.

The authors conclude with several points. The design of health promotion messages must be effective and must be incorporated into local cultural patterns. The study found that 95% of "aware" mothers liked the messages and identified with them. Message design must be based on further formative research and focus-group type activities. These messages must also be tailored to continue the trend toward proactive approaches to preventive health care. Messages should include full information and avoid creating a situation of over-expectations. In short, programmes should create "active demand" for services.