The prevalence of hepatitis B virus (HBV) in Wallis and Futuna (WAF) was one of the
highest in the Pacific and was the driving factor for introducing hepatitis B (HepB)
vaccination in 1992 and HepB birth dose (HepB-BD) in 2006. Using transmission assessment
survey (TAS) as a survey platform for eliminating lymphatic filariasis (LF), we assessed
HBV surface antigen (HBsAg) seroprevalence, HepB vaccination coverage, and its timeliness
among schoolchildren in WAF. From one finger prick of all registered fourth and fifth
grade students, we tested HBsAg and filariasis antigen simultaneously, and estimated
HepB vaccination coverage and timeliness by reviewing students' immunization cards.
Since the children targeted were born when the three-dose HepB schedule was 2, 3,
and 8 months, we defined timely vaccination if each dose was given by 3, 4, and 12
months. Of 476 targeted, 427 were enrolled. HBsAg prevalence was 0.9%. Estimated HepB
vaccination coverage was 97%, 97%, and 96% for the first, second, and third doses,
respectively, yielding coverage for all three doses of 96%. Proportion of timely vaccination
was lower: 80%, 56%, and 65%, respectively, and less than 50% for all three doses
combined. The seroprevalence of HBsAg among schoolchildren in WAF is less than 1%,
close to the control goal. HepB vaccination coverage was high, but many children were
vaccinated late. We recommend increasing the efforts for timely HepB vaccination.
By combining an HBV seroprevalence survey and coverage assessment, we demonstrated
the benefit of using TAS as a public health platform to access schoolchildren.