Evaluation of response to hepatitis B vaccine in Iranian 6–18‑year‑old students RTICLE Alizamen Salehifard Jouneghani, Morteza Hashemzadeh Chaleshtori1, Abolfazl Khoshdel2, Soleiman Kheiri3, A Effat Farrokhi1, Pooran Khalafian4, Zahra Aliyari4 Department of Pediatrics, Clinical Research Development Unit, Hajar Hospital, 1Cellular and Molecular Research Center, 2Clinical Research Development Unit, Hajar Hospital, 3Biostatistics and Epidemiology Department, Faculty of Health, 4Chaharmahal Va Bakhtiari Province Health Center, Shahrekord University of Medical Sciences, Shahrekord, Iran Background: Hepatitis B is a dangerous disease with high morbidity and mortality rates all around the world. Vaccination is the most important way to its prevention and control. This cross‑sectional study was carried out to study the levels of immunogenicity to RIGINAL hepatitis B vaccine in students. Materials and Methods: Six hundred and forty‑four students aged 6–18 years including 316 girls and 328 boys were selected from the Chaharmahal Va Bakhtiari province. Selected students had been received three doses of recombinant O vaccine (0, 1, and 6 months). Blood samples were taken and the titers of hepatitis B surface antigen were studied. Results: From a total of 644 students, 396 (61.5%) had a titer lesser than 10 mIu/ml and 248 (38.5%) had a titer higher than 10 mIu/ml. Therefore, the level of respond to vaccine with 95% confidence was 38.5% (34.7%–42.4%). Levels of respond to vaccine were related to age, body mass index (BMI), and educational level and were not related to sex and habit of students. Conclusion: Reverse significant relation was seen between the respond to vaccine and age and BMI in a way which the titers of antibody were lower in students with higher age and BMI. Key words: Hepatitis B, immunization, body mass index, age, hepatitis B surface antigen How to cite this article: Jouneghani AS, Chaleshtori MH, Khoshdel A, Kheiri S, Farrokhi E, Khalafian P, et al. Evaluation of response to hepatitis B vaccine in iranian 6–18‑year‑old students. J Res Med Sci 2017;22:116. INTRODUCTION at birth,[6] even 51% had these protective levels 30 years after receiving the primary series without subsequent Despite universal vaccination against hepatitis B doses.[7] virus (HBV), an infection with this pathogen continues to be responsible for important morbidity and mortality Hepatitis B vaccine has been shown to be highly all around the world.[1] It has been an international effective in preventing infection with HBV. The hepatitis health problem estimated to lead to between 500,000 and B vaccine was introduced in the early 1980s. In 1991, 1.2 million deaths every year.[2] Incidence of infection the World Health Organization recommended that all with HBV estimates range between 0.1% and 0.7% in countries introduce hepatitis B vaccination into their Northern, Western, and Central Europe, whereas those national immunization programs. In Iran, vaccination significantly higher in Southern and Eastern Europe.[3,4] against HBV is recommended for all infants, previously In the Middle East and North Africa, the prevalence of unvaccinated children, and unvaccinated adults at HBV infection is different such as 7.4% in Iran, 9.8% high risk in an attempt to achieve lifelong protection in Egypt, 6.9% in Libya, 2.4% in Lebanon, 2.6% in against HBV infection.[8] Immunization with this Palestine, 8.6% in Israel, and 6.1% in Saudi Arabia.[5] In vaccine starting at birth has dramatically reduced the North America, 41% had anti‑hepatitis B surface (HBs) subsequent development of chronic hepatitis B in young levels of >10 mIU/ml 7–9 years after booster vaccination children from perinatal or early childhood exposure to HBV.[9‑11] Access this article online Quick Response Code: Website: This is an open access article distributed under the terms of the www.jmsjournal.net Creative Commons Attribution‑NonCommercial‑ShareAlike 3.0 License, which allows others to remix, tweak, and build upon the work non‑commercially, as long as the author is credited DOI: and the new creations are licensed under the identical terms. 10.4103/jrms.JRMS_204_17 For reprints contact: [email protected] Address for correspondence: Prof. Abolfazl Khoshdel, Department of Pediatrics, College of Medicine, Shahrekord University of Medical Sciences, Shahrekord, Iran. E‑mail: [email protected] Received: 11‑03‑2017; Revised: 07‑06‑2017; Accepted: 25‑07‑2017 1 © 2017 Journal of Research in Medical Sciences | Published by Wolters Kluwer - Medknow | 2017 | Jouneghani, et al.: Response to hepatitis B vaccine in students Various investigations have been reported that type of student selection) was done. Five milliliters of venous vaccine, the number of injections, site of injection, the use blood was taken from each student by venipuncture into of adjuvant materials, and storage conditions of vaccines sterile tubes. The sera samples were separated using cause differences in the immunogenicity of the hepatitis B centrifugation (Hettich, Germany). Serum samples were vaccine.[12] In keeping with this, the potential effects of the then stored at −20°C until analyses were performed. genetic, age, weight, and a history of alcohol, drugs, and narcotic materials consumption in the immunogenicity Evaluation of sera titers of hepatitis B vaccine should not be overlooked.[12] All of the sera samples were analyzed for the titers Approximately 4%–10% of healthy, immunocompetent of antibodies against HBV using HbsAb commercial individuals fail to mount protective levels of antibodies to kit (Diapro, Italy) according to the manufacture’s recombinant HBs antigen (HBs Ag) after completing the instruction. Results were analyzed and those that had a standard HBV vaccination schedule.[13] However, the levels titer lower than 10 mIu/ml were analyzed for the presence of immunity against hepatitis B vaccine in Iran and other of HBV antigen using the HBsAg commercial kit (Diapro, sites of the world had a range of 70%–95%.[7,8] The previous Italy) according to the manufacture’s instruction. The sera investigation revealed that age of patients had a significant samples which were negative for the presence of HBsAg effect on the seroprevalence of hepatitis.[14] were analyzed for the M class antibodies against C antigen of the HBV using the HBcAb (IgM) commercial kit (Diapro, There were no previously published data on the evaluation Italy) according to the manufacture’s instruction. of the levels of immunity against hepatitis B vaccine in Iran. Therefore, the present investigation was carried out Statistical analysis to evaluate the levels of response to the hepatitis B vaccine Statistical analysis was done using the mean ± standard in Iranian 6–18‑year‑old students. deviation for quantitative variables and the number and percentage for qualitative variables. Chi‑square and MATERIALS AND METHODS independent t‑test were used to study the relation between sex, location, age, and education level with respond to Ethics vaccination and spearman correlation coefficient was used This study was approved by the Ethical Committee of to study the relation between titers of antibodies with Department of Pediatrics, College of Medicine, Shahrekord age and body mass index (BMI) of students. The logistic University of Medical Sciences, Shahrekord, Iran (Consent regression was used to determine the relation between Ref Number: IR.SKUMS.REC. 1394.195). All samples were respond to vaccination and sex, BMI, and educational obtained after informed consent had been given; as patients level of students. Statistical analysis was performed using were under age, approval was obtained from parents. SPSS/21.0 (SPSS Inc., Chicago,IL, USA) and significance was regarded at a P < 0.05. Samples This cross‑sectional study was conducted on 6–18‑year‑old RESULTS students of different regions of the Chaharmahal Va Bakhtiari province, Iran on 2016 year. Samples were taken Of 644 samples studied, 328 students (50.9%) were boy from students at different educational levels including and 316 students (49.1%) were girl. Three‑hundred and primary (6–11‑year‑old including the students of first, forty‑nine students (54.2%) were from primary school, 148 second, third, fourth, fifth, and sixth educational levels), students (23%) from secondary, and 147 students (22.8%) secondary (guidance) (11–13 years old including the from tertiary schools. Samples were gathered from students of seventh, eighth, and ninth educational levels), seven different regions of the Chaharmahal Va Bakhtiari and tertiary students (14–18‑years old including the students province, Shahrekord county with 236 students (36.6%) of first, second, third, and fourth educational levels). had the most, and Kiar and Kohrang countries each one with 24 students (3.7%) had the least sample sizes. Totally, The sample size was calculated based on assuming a 15% 248 students (38.5%) had a positive respond (responder) and for nonrespond[6‑8] to vaccine using a 95% confidence and 396 students (61.5%) had a negative respond (nonresponder) assuming 20% relative error. The sample size obtained to the vaccination. Therefore, the level of respond to vaccine as 544 students. To increase the precision, 100 additional with 95% confidence was 38.5% (34.7%–42.4%). samples were considered, and finally 644 students were selected randomly and studied. All children received Table 1 represents the levels of response to the hepatitis three doses of recombinant hepatitis B vaccine at the B vaccine in the students based on the sex and location. birth, after 1 month, and after 6 months. Three‑stage Totally, there were no statistically significant differences random sampling (school selection, class selection, and between the levels of response to hepatitis B vaccine and sex | 2017 | Journal of Research in Medical Sciences 2 Jouneghani, et al.: Response to hepatitis B vaccine in students and location of students. The highest percent of response Table 1: Levels of response to the hepatitis B vaccine to vaccine was found for girl students (39.6%) and also in in the students of Chaharmahal Va Bakhtiari province the Kiar region (45.8%).