A new study from researchers at the All India Institute of Medical Sciences concluded that preterm infants born in areas that are endemic for hepatitis B may require four doses of hepatitis vaccine, instead of the currently recommended three. The team studied 60 term infants with intrauterine growth retardation (term-IUGR) and 82 premature infants; both groups received four doses of a recombinant hepatitis B vaccine, administered at birth, six weeks, 10 weeks, and 14 weeks of age. According to their report in the September issue of Acta Paediatrica, the number of babies who had protective levels of antibodies after the third dose of vaccine was much higher in the term-IUGR group than in the group of premature infants. Antibody titers in the preterm group improved significantly, however, after the fourth dose of vaccine, bringing them to levels similar to the term-IUGR group.