The concept of vaccine hesitancy was recently defined by the WHO as the “delay in acceptance or refusal of vaccines despite availability of vaccination services. Vaccine hesitancy is complex and context specific varying across time, place and vaccines. It includes factors such as complacency, convenience and confidence.” Vaccine hesitancy makes inherent sense to us in the US, where we see it in Jenny McCarthy and Andrew Wakefield as a refusal to undertake perceived risks by receiving a vaccine due to fears about the vaccine contents, or perhaps unfounded concerns about vaccines causing autism. However, the idea that vaccine hesitancy could exist outside of a developed country framework has not been thoroughly researched in the same way. Thus the motivation behind this project was to investigate whether any sort of vaccine hesitancy (using the WHO scale to assess hesitancy) existed in Addis Ababa, the capital of Ethiopia, and more importantly, whether those who had higher vaccine hesitancy scores had children with less timely vaccination schedules.
The study design was a cross-sectional survey, which meant that it was administered at one time point (as opposed to a longitudinal study). There are 10 sub-cities, an administrative division in Addis, and we wanted to reach a representative sample, so we randomly selected 5 of these 10 sub-cities, and then randomly selected one health center from each sub-city from a list of all the health centers (publicly run by the government) within each sub-city (See Figure 1, below). So altogether, we had five health centers, one in each of 5 distinct sub-cities. Then we administered the survey using nurses and data collectors in each health center and transcribed vaccine information on the children from their vaccination cards (Ethiopia uses paper vaccination cards to record vaccine information).
In the end, we surveyed 350 women, and found that while a high proportion of the surveyed children (82.3%) received all their recommended vaccines, although only 55.9% of these vaccinations were on time (including a one-month grace period for tardiness). However, not a lot of caregivers (3.4%) reported ever hesitating or refusing (3.7%) a vaccine for their child. The most important finding was that those with higher scores of vaccine hesitancy had almost twice the odds of having children with late vaccination (AOR 1.94, 95% CI: 1.02, 3.71) when we adjusted for confounding factors.
The real takeaway of this paper, though, is imagining those that we didn’t sample. Our study examined women who already had health-seeking behavior – they were sampled at their health center when they were taking their child to get vaccinated. That means that all those women who weren’t taking their children to get their vaccines were not included in our sample. Not only that, Addis Ababa has the highest vaccination rates in the entire country, with some of the poorer, more pastoralist regions near Somalia having a tiny fraction of the vaccination coverage found in Addis. This shows us a) how important sampling is, and how our study sample and population governs our findings, and b) how vaccine hesitancy may play an even greater role in untimely vaccination in communities with lower vaccination rates. More work needs to be done with a more generalized sample to answer these questions.
This paper was the culmination of my MPH capstone research project, where I designed this study and administered it over three months in the summer of 2017 while living in Addis Ababa and working at St. Paul’s hospital. Unfortunately I couldn’t really help with the data collection because my Amharic abilities were quite limited to food, transportation, and proximity of bathrooms (the necessities).
Masters NB, Abeje Y, Wagner AL, Boulton ML. Vaccine Hesitancy Among Caregivers and Association with Childhood Vaccination Timeliness in Addis Ababa, Ethiopia. Human Vaccines & Immunotherapeutics. doi:10.1080/21645515.2018.1480242.