Indian Pediatrics 2001; 38: 1160-1162
Hepatitis B Immunization in Adolescent Girls
Hepatitis B virus (HBV) is an important cause of acute and chronic morbidity an morality the world over. It is estimated that about two billion people have been infected and over 350 million people in the world are chronic carriers of the virus(1). The weighted prevalence of hepatitis B in India has been estimated to be 4.7%, which makes India an intermediate prevalence country(1). HB surface antigen positivity in children below 15 years ranged from 1.3%-12.7% in various studies and was not different from the adult population(2). This indicates that a major portion of the exposure to HBV takes place below 15 years of age. It is also estimated that 27.4% of all HBV exposures take place below 5 years of age(2). Chief sources of infection in India are mother to child transmission (vertical) and child to child transmission (horizontal)(2).
In the last few decades, research on the HBV has produced a vaccine which can effectively prevent infection and probably its sequelae (cirrhosis and primary hepato-cellular carcinoma) in virtually 100% of those who mount a response(3). Effective vaccina-tion programs have, also, successfully reduced vertical transmission of HBV from mothers to offspring(3).
Recombinant DNA vaccines have been demonstrated to be highly immunogenic with high rates of sero-protection(4). Sero-protection rates have been found to be over 96% after completion of all doses, irrespect-ive of the schedule used. Recently introduced universal immunization campaigns have by and large popularized the vaccine in the neonatal period. However, in view of the vertical transmission of the HBV, the pre-sently vulnerable population of young adolescent girls who will soon be mothers needs urgent protection. The aim of our study was to determine the efficacy of two recombinant DNA vaccines, in adolescent girls.
Subjects and Methods
The study was conducted in 10-14 years old adolescent school girls. The school was situated in lower socio-economic surround-ings. The study was approved by ethical review board of the institute. One hundred and twenty girls were tested for HBsAg, anti-HBsAb, HBeAg and anti-HBeAg. All tested negative and were recruited for study. Written informed consent was taken. Vaccine was administered on schedule 0, 1 and 6 months. 20 mcg of either vaccine [Vaccine A-Engerix B (Smith Kline Beecham) and Vaccine B - Enivac HB (Panacea Biotec)] was adminis-tered randomly in the deltoid muscle. Quantitative anti-HbsAb analysis was done at KEM Hospital on days 90, 180 and 210. The quantitative anti-HBsAb analysis was done using Abbot Labs Kits (Auszyme 100T). Neither the patients nor the laboratory per-sonnel were told of the brand of vaccine used.
One hundred and twelve girls completed this study. Seven girls dropped out for reasons such as illness and absence (n = 6), transfer (n = 1) and one child had to be omitted because of contamination of blood sample. The vaccine schedule was completed in 93.3% girls. Both the study groups were similar (p >0.05) in age, weight, height and hemoglobin status (Table I).
On day 90 after first dose, 100% sero-protection was seen with both the vaccines. The antibody titers for Vaccine A and Vaccine B ranged from 144-1600 mIU/ml and 128-1760 mIU/ml, respectively on day 90, from 248-2672 mIU/ml and 192-3320 mUI/ml, respectively, on day 180, and from 206-4240 mIU/ml and 340-4050 mIU/ml respectively on day 210. The mean GMT values are given in Table I.
No significant side effects or reactions were reported with any of the vaccines.
*Student ‘t’ test for difference between GMT of the two vaccines
The Indian Academy of Pediatrics (IAP) has recommended universal protection from HBV by vaccination programs in the newborn and beyond infancy(5). Although neonatal vaccination program is gaining widespread acceptance in our country, not enough stress is laid as yet on immunization in the other age groups especially young adolescents. Infec-tion with hepatitis B is an important public health problem and adolescent girls are especially at high risk for sexually transmitted disease (STD) and HBV infections. Hence it becomes imperative to protect these adoles-cents from hepatitis B and other infections. Further, active immunization of adolescent girls would effectively reduce vertical trans-mission of HBV, which is variously suggested as one of the chief sources of infections in India(2).
In the present study, 93.3% of girls completed the vaccination series. The response was enthusiastic and dropout rate was low. In contrast to this a study in US by Middleman et al. found that only 72% completed vaccination series in an adolescent group(6). The better completion rate in our study could be due to the fact that it was school based with full support of the school authorities and could hence be carried out in a controlled and structured manner. The study also provided an excellent health education opportunity for children, parents and teachers.
In our study, both the vaccines produced 100% sero-protection. GMT levels were similar at 90 and 180 days but were higher at 210 days in favour of Vaccine B (p <0.05) (Table I). The only side effect reported in some patients following vaccination was pain at injection site. Reactogenicity studies on recombinant hepatitis B vaccine have reported only 1.14% adverse effects in 5456 unselected adults and children(7). Our study demons-trates that both vaccines are safe and effica-cious for prophylaxis against Hepatitis B.
Grateful acknowledgement is made to the school authorities of Hutatma Rajguru Vidyalaya, Pandav Nagar, Pune 411 016 for their co-operation. Acknowledgement is also made to the Medical Social Workers, nurses and laboratory technicians of department of Pediatrics, KEM Hospital, Pune for their help in carrying out the study. We would also like to thank Drs. Deepika Sharma, Shalini Rao and Paranjit Singh for their technical assistance in the study.
Contributors: SwB participated in data collection and helped in drafting the paper. DJ participated in data collection. SN was responsible for quantitative anti-HbsAg analysis. AB designed the study and also helped in interpretation of the study. ShB interpreted the study and drafted the paper. AP is the chief-co-ordinator of the study and will act as guarantor for the paper.
Funding: The study received financial support from M/s. Panacea Biotec who supplied the doses of hepatitis B vaccine and provided the kits for antibody titers.
Competing interests: Panacea Biotec Limited, New Delhi, manufacturers of hepatitis B vaccine, provided a research grant for conducting the study. DJ was paid a research fellowship through this grant.