Epidemiology of the Unimmunized Child: Findings from the Grey Literature

"Communication can play an important role in disseminating information about important health issues and available health care services."

At the request of the World Health Organization (WHO), IMMUNIZATIONbasics - the global United States Agency for International Development (USAID)-funded project (2004 to 2009) - undertook a review of the "grey literature" on the epidemiology of the unimmunised child in developing countries. The Centers for Disease Control and Prevention (CDC) conducted a parallel review of the peer-reviewed literature. (See Related Summaries, below.)

Conducted from May through August 2009, the review included studies, reviews, and reports that: addressed routine immunisation (RI) services, described activities carried out since 1980, and reported on systematically collected information about unvaccinated children. The IMMUNIZATIONbasics team reviewed approximately 160 documents from the grey literature. Of these, 126 were selected for this review. Sixty-two (53.9%) of the 115 country or regional documents focused on Africa, 38 (33.0%) Asia, 9 (7.8%) Latin America, 4 (3.5%) the Middle East, and 2 (1.7%) Europe. India was addressed in 18 documents, Kenya in 11, and Bangladesh in 10. The framework used for classifying factors affecting receipt of vaccines included: immunisation system, communication and information, family characteristics, and parental attitudes/knowledge.

"The situations, purposes, design and execution of the studies reported in the grey literature varied widely. Some were either designed or implemented in ways that limited or biased the type of information that they would find. Studies that used one approach, particularly closed-ended questions based on their own perceptions of what was important, were unlikely to uncover certain potentially important determinants." Furthermore, in terms of the grey literature review itself, several limitations are noted: 1) the fact that coding factors was a somewhat subjective process in that the reader made a judgment on whether a factor mentioned was significant or not, and 2) the reader also made a judgment on how to code particular information. For example, is a mother not knowing the return date in an exit interview a system problem (poor health worker communication), a problem of the mother's poor listening or understanding, or both?

That said, based on the counts of factors, service factors and parental attitudes and knowledge emerged as the most important explanations for non-immunisation. With regard to the latter, 58 studies mentioned the factor of parental practical knowledge as an important factor for non-immunisation. Numbers for other factors under this category included: fear of side effects (47 studies), conflicting priorities (43), religious/cultural/social beliefs/norms and rumours (41), perception of importance of vaccination for my child's health/attitude that it is better to treat illness (30), perceived efficacy of vaccine (27), lack of interest/motivation (19), lost/unavailable health cards (18), demand/acceptability of vaccination (15), autonomy of women/father or mother-in-law pressuring against/husband refusal (15), perceived safety of vaccine/fear of multiple doses/of vaccination procedures/of dirty needles (13), feeling of not belonging to the majority social group or otherwise being unaccepted, embarrassed (13), perception that child is too sick, too weak/fatalism (13), previous positive or negative experience at health services (e.g., turned away, post-vaccination abscesses, verbally abused, publically humiliated) (11), mistrust of health staff (11).

One sample communication-centred finding [numbers in brackets below correspond to studies that can be found in the document list that begins on page 37]: "Attitudes and behavior of health staff are one of the most important and frequently cited factors that discourage full immunization of children. The documents reviewed indicate that in many countries, at least some health workers treat mothers in an unfriendly, disrespectful, or even abusive manner. Health staff in various countries (e.g. Ethiopia [69], Zimbabwe [97]), Niger [54]), Kenya [2]), Bangladesh [15, 56, 91], W. Africa [19], Uganda [17], Benin [102], Nigeria [98]) reportedly scream at mothers who commit such transgressions as forgetting the child's card, missing a scheduled vaccination appointment, or having a dirty, poorly dressed or malnourished child. Mothers feel humiliated - which discourages them from coming back to the health center for further immunizations (15, 17, 30 [Kenya, Burkina Faso], 91, and 98)....Even in countries where this extreme behavior is not normal, health workers often communicate little and poorly with mothers, so that many mothers leave not knowing when to return and what to do about side effects (93). Over a third of mothers in Liberia said they were not informed about the return date. Health workers in Niger and Burkina Faso did not effectively communicate essential information to mothers before or during vaccination encounters (30). Mothers in Somalia were angry that health workers did not offer them information about side effects (57). Only half of mothers whose children were vaccinated in Guinea and Malawi were given information about vaccine reactions or the disease vaccinated against (41, 113). The 2008 EPI [Expanded Programme on Immunisation] review in Benin found that one of the principal reasons for non-vaccination was mothers' being unaware of the need to return or when or where to return (115). In Mozambique, three quarters of health workers said they always write the return dates on the child's card, but only one quarter of the cards actually had the return date written (101). In Uganda, however, over 80% of parents claimed that health staff advised them to return for more vaccinations (17), and in Dhaka 29 of 30 mothers leaving a clinic knew the return date (91). Good provider/parent communication was also reported in Armenia (125)."

The review also found that various studies report that lack of promotion or follow-up of RI was a reason parents did not ensure that their children were completely immunised. "There are special marketing campaigns, using mass media and significant social mobilization, designed to promote participation in polio campaigns, but many parents report that they did not receive any messages about routine vaccination programs....Far too many parents leave sessions without knowing important information about return visits, side effects, etc. One exception is reported in Zambia, where there is high demand for immunization because of the involvement of Neighborhood Health Committees, local leaders, churches, schools, and opinion leaders (72). Social mobilization committees established for immunization campaigns have been transformed to support routine immunization. Vietnam is also said to have very strong social mobilization that has led to generally high awareness and understanding of immunization (73)."

In conclusion, the authors note that, while the questions are simple - which children are unvaccinated and why? - "the answers are complicated, often involving a multiplicity of interacting factors....[I]n many instances, the mother or parents themselves may not be able to articulate the reasons [for forgoing vaccination], since they are likely to be some combination of beliefs, perceptions, knowledge and experiences."