In response, the government of St Kitts and Nevis sought to introduce a plasma-derived Hepatitis B vaccine to infants in 1988. The programme was discontinued because of public concerns about the risks of a plasma-derived product.
A recombinant Hepatitis B vaccine was successfully introduced to infants in 2000, as part of a pentavalent combination at ages two, four and six months as recommended. The Ministry of Health, however, was still interested in ascertaining the national prevalence of Hepatitis B infection.
In 2011, the Ministry of Health collaborated with the Caribbean Epidemiology Centre (CAREC) and the Pan American Health Organization (PAHO) to conduct a seroprevalence study to assess the response to the vaccine. The antenatal population was selected (n=317) since perinatal transmission and its sequelae are associated with significant morbidity and mortality in infants. The study found 3.2% of the pregnant women positive for HBsAg, and 52.4% of the pregnant women tested negative for anti-HBs.
These findings informed changes to the immunization policy and schedule. In October 2015, a birth dose of recombinant Hepatitis B vaccine was re-introduced with inoculation given within 24 hours of birth. This is in keeping with the PAHO/WHO's 2009 recommendations for a Hepatitis B vaccination schedule in an intermediate/moderate endemic zone.