School-based program expands HPV vaccine uptake in SG

A school-based immunization program in Singapore has resulted in high uptake and coverage of the human papillomavirus (HPV) vaccine, reports a study.

“Timely assessment of knowledge lapses and targeted intervention, strong partnerships with stakeholders, constant on-site adaptation, and positive social influence contributed to its success,” the researchers said. “This model can be applied to future school health programs.”

In this program, fully subsidized HPV vaccines were offered to all secondary 1 female students on an opt-in bases, starting as a rollout dose in 2019. Female students in secondary 2‒5 were also offered one-time catchup vaccination.

Data provided by the Ministry of Education schools were utilized to identify eligible recipients. In total, 19,144 students across 139 schools were offered the rollout dose, and 20,854 across 140 schools were offered the catchup doses.

Implementation of the school-based immunization program resulted in high uptake rates of 80.6 percent to 87.3 percent, which translated to high vaccine coverage of 90.3 percent to 93.4 percent. Very few students chose not to take the vaccine (1.5 percent to 1.9 percent). [Singapore Med J 2023;64:294-301]

Reported side effects were low at a rate of one in 1,000 students. Among recipients who reported side effects, those who received the second vaccine dose did so uneventfully.

Peer influence

“An accurate assessment of parental knowledge, attitude and practices, coupled with targeted solutions, can significantly improve uptake rates,” the researchers said. “Strong partnerships with stakeholders and constant groundwork evaluation and adaptation are key factors for success, while peer influence may have had some positive impacts on uptake rates and should be studied in greater detail.”

Notably, students exerted a positive influence on their peers through receptivity towards vaccination. Empirical studies showed that observing others could help with decision-making when an individual is facing uncertainty towards what to do. [Front Psychol 2019;10:1915]

“While not studied quantitatively, observations onsite during vaccination affirmed this,” the researchers said. “Several students who were initially afraid and apprehensive towards the vaccination were more accepting once the first few students in their class had been vaccinated.”

Earlier studies also suggested that the majority opinion could influence an individual’s beliefs and behaviours and may push them to conform to social norms. [Psychol Monographs Gen Appl 1956;79:1-70; Annu Rev Psychol 2004;55:591-621; Front Neurosci 2012;6:87; Dev Cogn Neurosci 2013;3:61-71]

“This implementation model can be applied to future health prevention programs in the school-going age group,” the researchers said.

The study had several limitations. First, the researchers did not analyse vaccine completion, as the index batch of students in both the rollout and catchup dose cohorts had not received their last dose during the study period. Second, follow-up on whether the students who had opted for vaccination at their family practitioner did indeed receive the vaccination was not completed.

“Further studies can be conducted to explore ideas and concerns regarding the HPV vaccine, and efforts to raise awareness and correct misconceptions regarding the vaccine should be expanded,” the researchers said.