Acceptability of the Dengue Vaccination among Parents in Urban Poor Communities of Quezon City, Philippines before and after Vaccine Suspension

"The dengue vaccine controversy triggered a change of attitude and understanding of parents who previously accepted the vaccine."

In 2016, the Philippines initiated a mass dengue vaccination in 3 urban regions; initial vaccine coverage was low, with low parental consent, especially in Metro Manila. In December 2017, the dengue vaccination was suspended amid a vaccine controversy. (Editor's note: This Guardian article summarises the controversy.) The study aims to illustrate the acceptability of the dengue vaccine before and after the vaccine programme suspension in an urban economically poor community.

Conducted by local health workers, initial vaccination was designed to reach 4th graders aged 9 and above in public schools for 3 doses in a 6-month interval. Children with parental consent were the ones only eligible for vaccination.

Twelve semi-structured in-depth interviews were conducted in November 2017 in urban economically poor communities of District 2 in Quezon City, Philippines. In January 2018, a month after dengue vaccine programme suspension, 5 focus group discussions were conducted with 41 parents of children who were vaccinated. The question guide was developed using the determinants on vaccine hesitancy.

In short, the researchers learned that the acceptability of the dengue vaccine was rooted in the previous vaccine experience of parents; those who had had good experience with government vaccinations accepted the vaccine when it was initially introduced in 2016. Some parents refused because their children had an adverse reaction, or they were afraid of the injection. Likewise, parents who refused the vaccination demanded more information on vaccine safety and benefits, especially if they had had previous reactions from other vaccines. Those who refused tended to know more about vaccines and refused the dengue vaccine specifically because they believed it had not been proven effective (being new). Parents whose children who had severe forms of dengue or knew someone who had died or had been hospitalised were likely to accept the vaccine.

During the controversy, most vaccine messages in the news media were on presumed vaccine-related deaths. This caused stress and anxiety among parents, who became hypervigilant about their children's health and changed their health-seeking behaviour. Trust in public health institutions was eroded, especially considering that the vaccination programme was linked with corrupt practices by health leaders. Trust in information being received from these institutions was low. Parents find it difficult to find trustworthy information sources. Health workers, especially local health workers and medical doctors, are the most cited trustworthy information sources, but the lack of avenues and confidence in discussing what happened to the vaccination has led to loss of trust in the dengue vaccination but also to other school vaccinations and public health programmes.

The initial implementation of the vaccination happened suddenly, and some parents wanted to participate but were unable to. This suddenness in implementation is seen to have contributed to the general lack of knowledge on vaccine-specific details such as number of doses, intervals, risks, and vaccination site. Parents preferred community-based interventions in communication with their local health workers in multiple forms, even if vaccination sites are in schools. They needed more information on dengue vaccine benefits, risks, and safety.

With the vaccine controversy, the communication received was perceived to be inadequate. Most of the parents received information from the news and not from their local health workers. Community-based communication strategies are preferred to allow parents to ask questions of the local medical doctors in their communities, who are expected to conduct the information dissemination.

The researchers conclude by stressing that parental experience with vaccination and dengue, trust in public health institutions, and the communication received by parents are interrelated. Communication strategies play vital role in addressing parental concerns and can be tailor-fitted and targeted. The lack of proper and adequate communication in the case studied here led to decreased trust in providers and eventually to poor experiences that, to the parents, justified non-acceptance of vaccines. During vaccine controversies, there is a demand for more and specific information; engagement with parents in eliciting and sharing information must be integrated in communication plans. Local health workers must have the capacity to respond to the need. Communication strategies must not be limited to knowledge transfers but rather focus on building trust.