Study of the safety, immunogenicity and seroconversion of a hepatitis-B vaccine in malnourished children of India G. Lakshmi*, P. Sudershan Reddy, K. Ratna Kumar, N.V. Bhavani, M. Dayanand Department of Paediatrics, Unit-III, Niloufer Hospital, Hyderabad, India Received 9 June 1999; received in revised form 20 October 1999; accepted 8 November 1999 Abstract Sixty rural children who were seronegative for HBV markers received three doses of 10 mg of a new Hepatitis-B vaccine, Revac-B (1 ml of vaccine contains 20 mg recombinant surface antigen) that was formulated from hepatitis-B surface antigen expressed in a recombinant strain of Saccharomyces cerevisiae. Vaccines were administered on a 0, 30 and 60-day schedule. Levels of anti-HBs titres were determined on the 30th, 60th and 90th days following the initial injection. None of the participants in the trial had serious adverse reactions and the frequencies of minor side eects were minimal. No clinically important adverse eects which could be considered as directly related to the vaccination were recorded. The volunteers showed a very good immune response and were seroprotected on the 30th day after the ®rst dose of vaccination. The present study revealed that the new vaccine, Revac-B is highly immunogenic and is well tolerated. 7 2000 Elsevier Science Ltd. All rights reserved. Keywords: Hepatitis B; Revac-B; Immunogenicity; Seroconversion; Hepatitis B vaccine 1. Introduction Hepatitis B is a disease of global distribution with an estimated 350 million persistent carriers worldwide [1]. Hepatitis B Virus (HBV) infection is responsible for a high proportion of the world cases of cirrhosis, and is the cause of up to 80% of all cases of hepato- cellular carcinoma (HCC) [2]. HBV is second only to tobacco among human carcinogens and HBV induced cirrhosis is the ninth most common cause of death world wide, taking more than one million lives each year [2]. Geographic patterns of HBV prevalence vary greatly on a global basis from areas of low endemicity, where less than 1% of adults are chronic carriers and less than 10% of the adult populations will experience infection, to areas of intermediate and high endemicity where between 2±15% of adults are chronic carriers and between 30±100% of the population will experi- ence infection [3±11]. There are nearly four billion in- dividuals who reside in areas of the world where Hepatitis B is of intermediate and high endemicity [12]. The major pathways for the transmission of HBV include parenteral exposure to blood or other infective body ¯uids, transmission from mother to infant, sexual transmission, and transmission to infants or young children from contacts with other infected persons [13]. It is generally agreed that control of hepatitis B is a high-priority public health objective on a worldwide basis. The only practical solution to the problem is recognized to be large-scale immunization of those at risk. The standard example cited is Taiwan, where such vaccination eorts have decreased HBV carrier status from 18 to 8% in the period from 1986 to 1993 [14,15]. The present study, which was designed with the Vaccine 18 (2000) 2009±2014 0264-410X/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved. PII: S0264-410X(99)00529-0 www.elsevier.com/locate/vaccine * Corresponding author. Technical Services, Bharat Biotech Inter- national Limited, 726, Venkateswara Hills, Banjara Hills, Road No. 3, Hyderabad - 500 034, India. Tel.: +91-40-3350794; fax: +91-40- 3350844. E-mail address: revacts@hotmail.com (G. Lakshmi).