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Immunity to hepatitis B vaccine among health care workers
Vaccine 29 (2011) 2727–2729
Contents lists available at ScienceDirect
Vaccine journal homepage: www.elsevier.com/locate/vaccine
Immunity to hepatitis B vaccine among health care workers Mohammad Hossein Baghianimoghadam a , Mahmod Nouri Shadkam b , Hossein Hadinedoushan c,∗ a
Health Services Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran Pediatrics Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran c Immunology Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Daneshjoy Blv., Pirapezeshki, Yazd, Iran b
a r t i c l e
i n f o
Article history: Received 19 August 2010 Received in revised form 18 January 2011 Accepted 27 January 2011 Available online 23 February 2011 Keywords: Immunity Hepatitis B vaccine College students
a b s t r a c t The aim of this study was to determine the level of anti-HBsAg (hepatitis B surface antigen) in vaccinated high risk group. We measured anti-HBsAg concentration in blood sera of adult students aged from 19 to 37 years old. Five milliliters (5 ml) of blood sample was taken from 210 cases four months after the second dose and 126 out of 210 cases three months after the third dose of hepatitis B vaccination. All blood samples were analyzed for anti-HBsAg by ELISA method. 125 out of 210 samples (59.5%) showed antiHBsAg concentrations higher than 20 mIu/ml and considered immune after the second dose of hepatitis B vaccination. Also, 99.2% of samples had anti-HBsAg higher than 20 mIu/ml three months after the third dose of the vaccination. Non-immune cases in males were more than females (41.2% vs.40.1%). In conclusions, our results reinforce the importance of hepatitis B vaccine in adolescents and suggest that three dose of hepatitis B vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction Hepatitis B virus (HBV) is a double strand, enveloped DNA virus of the hepadnaviridae family, which replicates in the liver and causes hepatic dysfunction [1]. The currently acknowledged risk factors for infection by HBV are sexual promiscuity, intravenous drug abuse, blood and derivatives transfusions, hemodialysis and needle accidents among healthcare workers. The HBV is transmitted through serum and even body fluids such as semen, saliva, sweat, tears or breast milk [2]. Hepatitis B is one of the most common infectious diseases in the world. It is estimated that one third of the world’s population has been infected and over 350 millions people are chronic carriers. HBV infection results in an estimated 620,000 to 1 million death annually [3]. In the United States more than 330,000 new cases of hepatitis B occur per year [4]. Infection with hepatitis B virus may progress to chronic liver diseases including cirrhosis and hepatocellular carcinoma, one of the most common kinds of cancers in the world. Following acute HBV infection, between 1–10% of adults and 30–90% of children become chronic carries, a part of whom at risk of developing life threatening disease [5]. Chronic hepatitis B is a cause of morbidity and mortality worldwide.
∗ Corresponding author. Tel.: +98 351 6233235; fax: +98 351 6238561. E-mail address: [email protected] (H. Hadinedoushan). 0264-410X/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.vaccine.2011.01.086
There are a large number of hepatitis B carriers in Iran. It is estimated that over 35% of Iranians have been exposed to the HBV and about 3% are chronic carriers, ranging from 1.7% in Fars province to over 5.1% in Golestan [6,7]. The discovery that passively acquired anti-hepatitis B surface antigen (anti-HBsAg) could protect individuals from acute clinical hepatitis B and chronic HBV infection if given soon after exposure led to the development of a specific antibody containing high titer of anti-HBsAg. Vaccination against hepatitis B is the most effective measurement to control and prevent hepatitis B on global scale [8]. Safe, immunogenic and effective hepatitis B vaccines have been commercially available in the United State since 1981. In Iran, vaccination against HBV has been routinely performed for all infants that were born to HBsAg negative mothers and high-risk groups since 1992. The protective efficacy of hepatitis B vaccination is directly related to development of anti-HBsAg [9]. Anti-HBsAg levels of 10 mIu/ml or higher are considered to be 100% protected against clinical illness and chronic infection. The vaccines produced by each manufacturer have been evaluated in clinical trials to determine the age-specific dose that achieves the maximum seroprotection rate. There are few studies focused on the seropositive rate of protective antibody, named anti-HBsAg, among adolescents in Iran. The objective of the present study was to determine the level of antiHBsAg and immunity to hepatitis B infection in vaccinated high risk group. To achieve the purpose of the study, anti-HBsAg concentration in blood sera of vaccinated students aged from 19 to 37 years old were collected and analyzed.
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M.H. Baghianimoghadam et al. / Vaccine 29 (2011) 2727–2729
2. Materials and methods Two-hundred and fifteen college students of Health, Nursing and Paramedical faculties of Yazd University of Medical Sciences, Yazd, Iran were vaccinated against hepatitis B (Hepavax-gene, DNA recombinant hepatitis B vaccine, 100 g). The vaccine was administered intramuscularly in the anterolateral thigh. Cases did not receive a booster dose of hepatitis B vaccines previously and had not hepatitis B infection history. A questionnaire was used to record demographic information from participants. This project was approved by ethic community of Yazd University of Medical Sciences. Signed informed was obtained from each sample. Two-hundred and ten participants were vaccinated two months after the first vaccination for the second dose. Five milliliters (5 ml) of blood were taken four months after the second dose of vaccination from 210 cases who accepted to be as a blood donor. Immediately after blood taking, all of individuals were received the third dose of vaccine. Three months after third dose vaccination, 5 ml of blood were obtained from 126 out of 210 cases who accepted to be a blood donor. Blood samples were collected in non-anticoagulant sterile tubes and centrifuged. Sera sample were stored at −70 ◦ C until used. All blood samples were analyzed for antibody to hepatitis B surface antigen by enzyme-linked immune sorbet assay (ELISA) method using commercially kit according to the manufacture’s instruction (Diaplus Inc., USA). Briefly, 50 l of standards, controls and each sample were added to the appropriated wells and in the same time 50 l of the enzyme conjugate reagent were added to each well and incubated at 37 ◦ C for 60 min. Microtiter plate was washed four times with wash buffer and one time with distilled water. 100 l TMB-substrate was added to each well and incubated at 37 ◦ C for 20 min and the reaction stopped by adding l00 l of stop solution. The absorbances were read at 450 nm wavelength with 620 nm as reference. We considered cases as sera positive against hepatitis B if their anti-HBsAg antibody concentration was equal or greater than 20 mIu/ml, and seronegative if the concentration was less than 20 mIu/ml according to the Kit instruction. 2.1. Statistical analysis The data of demographic variables and anti-HBsAg concentration were transferred to SPSS software version 15. T-test and Pearson Chi-square test were used for data analysis. The p < 0.05 was considered statistically significant. 3. Results Two-hundred and ten participants, who gave consent for bleeding after the second dose of vaccine administration, were 67.6% females and 32.4% males. The age range of the participants was from 19 to 37 years with a mean age of 22.9 years. 126 Volunteers (67.5% females, 32.5% males) gave consent for bleeding after third dose of HB vaccine. The mean age of them was 22.4 years old (range 19–36). 85 out of 210 samples (40.5%) who gave their consent for blood sampling 4 months after the second dose HB vaccination showed anti-HBsAg concentration lower than 20 mIu/ml and considered non-immune. 46.2% of them had anti-HBsAg 20–100 mIu/ml. Concentrations of antibody in 13.3% of samples were higher than 100 mIu/ml and the highest value was 142 mIu/ml. We evaluated anti-HBsAg concentrations in 126 persons 3 months after the third vaccination. The results indicated that 99.2% of them had anti-HBsAg higher than 20 mIu/ml and only one sample was non-protective. 85 Samples (67.5%) had antibody 20–100 mIu/ml and in 31.7% of the cases, the levels of antibody were higher than 100 mIu/ml. Also, the highest value of antibody was 187 mIu/ml. Fig. 1 shows the amount of anti-HBsAg in samples
Fig. 1. The concentration of anti-HBsAg in study group after the second dose of vaccine.
base on gender after the second vaccination. Non-immune participants in males were more than females (41.2% vs. 40.1%). As a result of Fig. 2, anti-HBsAg of more than 20 mIu/ml after third dose vaccine administration was seen in 100% of males and 98.8% of females. Overall, the level of anti-HBsAg in 71.1% of women and 61.2% of men were 20–100 mIu/ml. Also, 28.9% of women and 38.9% of men had Anti-HBsAg higher than 100 mIu/ml. The mean of immunity to HB vaccine in the second (59.5%) and the third (99.2%) administration vaccine was significant (p = 0.001). There was a significant reciprocal correlation between age and anti-HBsAg production in response to second (p = 0.045, R = −0.247) and third vaccination (p = 0.0266, R = −0.325). Besides, there was not a significant difference between the sex and amount of antibody production in response to the second (p = 0.54) and the third vaccination (p = 0.48). 4. Discussion Effective vaccines against HB have become available in 1982. Their widespread use in many areas of the world has dramatically reduced the rate of HB. In Iran, in spite of the availability of an effective vaccine and the incorporation of HBV in to the national infant vaccination program, now it is recommended to be vaccinated high risk adults that were not vaccinated in infancy. It is important to know the rate of protection of HB vaccination in adults. In this study, the concentrations of anti-HBsAg after the second and the third vaccination in high risk adults group were determined and efficacy of vaccine was assessed. We defined anti-HBsAg antibody concentration of 20 mIu/ml as the seropositive threshold, as recommended by ELISA kit instruction. The findings showed that 40.5% of individ-
Fig. 2. The concentration of anti-HBsAg in study group after the third dose of vaccine.
M.H. Baghianimoghadam et al. / Vaccine 29 (2011) 2727–2729
uals had not anti-HBsAg in serum after the second vaccination that recommended there is a need for a third booster immunization to maintain protection in them. In this research, 99.2% of the samples had anti-HBsAg higher than 20 mIu/ml in their serum after the third dose of vaccine. The results indicated that the vaccine of HB is effective, and the boost of HBV vaccine is necessary for adolescents to increase the seropositive rate of anti-HBsAg in adults. Some studies showed that giving a booster dose of HB vaccine to persons who have been vaccinated and the concentration of anti-HBsAg was below 10 mIu/ml could develop a rapid rise in anti-HBsAg antibody [10]. One report has revealed that vaccination at older ages was associated with persistence of higher anti-HBsAg level [11], which supported the effectiveness of booster in adolescents rather than younger age. Lu et al. found that 100% of 15–18 years-old adolescents, after receiving booster dose of recombinant HBV vaccine developed antibody [12]. Immune response rates among health care workers in Hong Kong were examined. There was a good overall response rate of 93.8%, women responding better than men [13]. In the study by Roome et al., Connecticut public safety personnel had been vaccinated using Recombivax HB of 528 individuals, 11.9% were found to have no or inadequate levels of antibody. The frequency of inadequate level of antibody increased significantly with age, from 2.8% among those younger than 30 years to 42.1% among those older than 60 years [14]. A study which was carried out by Chen, demonstrated that after 1984 that the free HBV vaccination program in Taiwan has been provided to the newborns, the HBV infection rate and HBsAg carriers rate decreased. This study demonstrated the protective of public HBV vaccination among university students older than 18 years of age [15]. It was also found that, there was not a significant difference between sex and anti-HBsAg concentration. This means the percentage of male no responders are equal to female participants and anti-HBsAg production is not affected by sexual factor such as feminine hormones. Another finding of our results is the significant differences between age and antibody production. In other words, as age increased, the antibody production decreased. It is known that increasing age is associated with a decline in humoral and cellular immunity to vaccines [16]. 5. Conclusions Our results reinforce the importance of HB vaccine in adolescents and suggest that three dose of HB vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults.
2729
Acknowledgments This work was supported by Shahid Sadoughi University of Medical Sciences. The authors thank Mrs. Laleh Pedram for her technical assistance and Mr. Amin Dehghan for his critical reading and editing of this manuscript. References [1] Mahoney FJ. Update on diagnosis, management, and prevention of hepatitis B virus infection. Clin Microbiol Rev 1999;12:351–66. [2] Beasley RP, Hwang LY, Lin CC, Ko YC, Twu SJ. Incidence of hepatitis among students at a university in Taiwan. Am J Epidemiol 1983;117:213–22. [3] Hammitt LL, Hennessy TW, Fiore AE, Zanis C, Hummel KB, Dunaway E, et al. Hepatitis B immunity in children vaccinated with recombinant hepatitis B vaccine beginning at birth: a follow-up study at 15 years. Vaccine 2007;28: 6958–64. [4] Coleman PJ, McQuillan GM, Moyer LA, Lambert SB, Margolis HS. Incidence of hepatitis B virus infection in the United States, 1976–1994: estimates from the National Health and Nutrition Examination Surveys. J Infect Dis 1998;178:954–9. [5] Kane MA. Global status of hepatitis B immunization. Lancet 1996;14:696. [6] Malekzadeh R, Khatibian M, Rezvan H. Viral hepatitis in the world and Iran. J Irn Med Council 1997;15:183–200. [7] Merat S, Rezvan H, Nouraie M, Jamali A, Assari S, Abolghasemi H, et al. The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran: a population-based study. Arch Iran Med 2009;12: 225–31. [8] Poorolajal J, Mahmoodi M, Majdzadeh R, Nasseri-Moghaddam S, Haghdoost A, Fotouhi A. A long-term protection provided by hepatitis B vaccine and need for booster dose: a meta-analysis. Vaccine 2010;28:623–31. [9] Hadler SC, Francis DP, Maynard JE, Thompson SE, Judson FN, Echenberg DF, et al. Long-term immunogenicity and efficacy of hepatitis B vaccine in homosexual men. N Engl J Med 1986;315:209–14. [10] Milne A, Waldon J. Recombinant DNA hepatitis B vaccination in teenagers: effect of a booster at 5 1/2 years. J Infect Dis 1992;166:942. [11] McMahon BJ, Bruden DL, Petersen KM, Bulkow LR, Parkinson AJ, Nainan O, et al. Antibody levels and protection after hepatitis B vaccination: results of a 15-year follow-up. Ann Intern Med 2005;142:333–41. [12] Lu JJ, Cheng CC, Chou SM, Hor CB, Yang YC, Wang HL. Hepatitis B immunity in adolescents and necessity for boost vaccination: 23 years after nationwide hepatitis B virus vaccination program in Taiwan. Vaccine 2009;5: 6613–8. [13] Lim WL, Wong DA, Cheng KC. Immune response to hepatitis B vaccine in health care workers in Hong Kong. HKMJ 1996;2:138–40. [14] Roome AJ, Walsh SJ, Cartter ML, Hadler JL. Hepatitis B vaccine responsiveness in Connecticut public safety personnel. JAMA 1993;270:2931–4. [15] Chen CC, Yen CH, Wu WY, Hu SW, Chen SC, Bell WR, et al. Epidemiology of hepatitis B virus infection among young adults in Taiwan, China after public vaccination program. Chin Med J 2007;5:1155–8. [16] Burns EA, Lum LG, L’Hommedieu G, Goodwin JS. Specific humoral immunity in the elderly: in vivo and in vitro response to vaccination. J Gerontol 1993;48:B231–6.
Contents lists available at ScienceDirect
Vaccine journal homepage: www.elsevier.com/locate/vaccine
Immunity to hepatitis B vaccine among health care workers Mohammad Hossein Baghianimoghadam a , Mahmod Nouri Shadkam b , Hossein Hadinedoushan c,∗ a
Health Services Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran Pediatrics Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran c Immunology Dep., Shahid Sadoughi University of Medical Sciences and Health Services, Daneshjoy Blv., Pirapezeshki, Yazd, Iran b
a r t i c l e
i n f o
Article history: Received 19 August 2010 Received in revised form 18 January 2011 Accepted 27 January 2011 Available online 23 February 2011 Keywords: Immunity Hepatitis B vaccine College students
a b s t r a c t The aim of this study was to determine the level of anti-HBsAg (hepatitis B surface antigen) in vaccinated high risk group. We measured anti-HBsAg concentration in blood sera of adult students aged from 19 to 37 years old. Five milliliters (5 ml) of blood sample was taken from 210 cases four months after the second dose and 126 out of 210 cases three months after the third dose of hepatitis B vaccination. All blood samples were analyzed for anti-HBsAg by ELISA method. 125 out of 210 samples (59.5%) showed antiHBsAg concentrations higher than 20 mIu/ml and considered immune after the second dose of hepatitis B vaccination. Also, 99.2% of samples had anti-HBsAg higher than 20 mIu/ml three months after the third dose of the vaccination. Non-immune cases in males were more than females (41.2% vs.40.1%). In conclusions, our results reinforce the importance of hepatitis B vaccine in adolescents and suggest that three dose of hepatitis B vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults. © 2011 Elsevier Ltd. All rights reserved.
1. Introduction Hepatitis B virus (HBV) is a double strand, enveloped DNA virus of the hepadnaviridae family, which replicates in the liver and causes hepatic dysfunction [1]. The currently acknowledged risk factors for infection by HBV are sexual promiscuity, intravenous drug abuse, blood and derivatives transfusions, hemodialysis and needle accidents among healthcare workers. The HBV is transmitted through serum and even body fluids such as semen, saliva, sweat, tears or breast milk [2]. Hepatitis B is one of the most common infectious diseases in the world. It is estimated that one third of the world’s population has been infected and over 350 millions people are chronic carriers. HBV infection results in an estimated 620,000 to 1 million death annually [3]. In the United States more than 330,000 new cases of hepatitis B occur per year [4]. Infection with hepatitis B virus may progress to chronic liver diseases including cirrhosis and hepatocellular carcinoma, one of the most common kinds of cancers in the world. Following acute HBV infection, between 1–10% of adults and 30–90% of children become chronic carries, a part of whom at risk of developing life threatening disease [5]. Chronic hepatitis B is a cause of morbidity and mortality worldwide.
∗ Corresponding author. Tel.: +98 351 6233235; fax: +98 351 6238561. E-mail address: [email protected] (H. Hadinedoushan). 0264-410X/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.vaccine.2011.01.086
There are a large number of hepatitis B carriers in Iran. It is estimated that over 35% of Iranians have been exposed to the HBV and about 3% are chronic carriers, ranging from 1.7% in Fars province to over 5.1% in Golestan [6,7]. The discovery that passively acquired anti-hepatitis B surface antigen (anti-HBsAg) could protect individuals from acute clinical hepatitis B and chronic HBV infection if given soon after exposure led to the development of a specific antibody containing high titer of anti-HBsAg. Vaccination against hepatitis B is the most effective measurement to control and prevent hepatitis B on global scale [8]. Safe, immunogenic and effective hepatitis B vaccines have been commercially available in the United State since 1981. In Iran, vaccination against HBV has been routinely performed for all infants that were born to HBsAg negative mothers and high-risk groups since 1992. The protective efficacy of hepatitis B vaccination is directly related to development of anti-HBsAg [9]. Anti-HBsAg levels of 10 mIu/ml or higher are considered to be 100% protected against clinical illness and chronic infection. The vaccines produced by each manufacturer have been evaluated in clinical trials to determine the age-specific dose that achieves the maximum seroprotection rate. There are few studies focused on the seropositive rate of protective antibody, named anti-HBsAg, among adolescents in Iran. The objective of the present study was to determine the level of antiHBsAg and immunity to hepatitis B infection in vaccinated high risk group. To achieve the purpose of the study, anti-HBsAg concentration in blood sera of vaccinated students aged from 19 to 37 years old were collected and analyzed.
2728
M.H. Baghianimoghadam et al. / Vaccine 29 (2011) 2727–2729
2. Materials and methods Two-hundred and fifteen college students of Health, Nursing and Paramedical faculties of Yazd University of Medical Sciences, Yazd, Iran were vaccinated against hepatitis B (Hepavax-gene, DNA recombinant hepatitis B vaccine, 100 g). The vaccine was administered intramuscularly in the anterolateral thigh. Cases did not receive a booster dose of hepatitis B vaccines previously and had not hepatitis B infection history. A questionnaire was used to record demographic information from participants. This project was approved by ethic community of Yazd University of Medical Sciences. Signed informed was obtained from each sample. Two-hundred and ten participants were vaccinated two months after the first vaccination for the second dose. Five milliliters (5 ml) of blood were taken four months after the second dose of vaccination from 210 cases who accepted to be as a blood donor. Immediately after blood taking, all of individuals were received the third dose of vaccine. Three months after third dose vaccination, 5 ml of blood were obtained from 126 out of 210 cases who accepted to be a blood donor. Blood samples were collected in non-anticoagulant sterile tubes and centrifuged. Sera sample were stored at −70 ◦ C until used. All blood samples were analyzed for antibody to hepatitis B surface antigen by enzyme-linked immune sorbet assay (ELISA) method using commercially kit according to the manufacture’s instruction (Diaplus Inc., USA). Briefly, 50 l of standards, controls and each sample were added to the appropriated wells and in the same time 50 l of the enzyme conjugate reagent were added to each well and incubated at 37 ◦ C for 60 min. Microtiter plate was washed four times with wash buffer and one time with distilled water. 100 l TMB-substrate was added to each well and incubated at 37 ◦ C for 20 min and the reaction stopped by adding l00 l of stop solution. The absorbances were read at 450 nm wavelength with 620 nm as reference. We considered cases as sera positive against hepatitis B if their anti-HBsAg antibody concentration was equal or greater than 20 mIu/ml, and seronegative if the concentration was less than 20 mIu/ml according to the Kit instruction. 2.1. Statistical analysis The data of demographic variables and anti-HBsAg concentration were transferred to SPSS software version 15. T-test and Pearson Chi-square test were used for data analysis. The p < 0.05 was considered statistically significant. 3. Results Two-hundred and ten participants, who gave consent for bleeding after the second dose of vaccine administration, were 67.6% females and 32.4% males. The age range of the participants was from 19 to 37 years with a mean age of 22.9 years. 126 Volunteers (67.5% females, 32.5% males) gave consent for bleeding after third dose of HB vaccine. The mean age of them was 22.4 years old (range 19–36). 85 out of 210 samples (40.5%) who gave their consent for blood sampling 4 months after the second dose HB vaccination showed anti-HBsAg concentration lower than 20 mIu/ml and considered non-immune. 46.2% of them had anti-HBsAg 20–100 mIu/ml. Concentrations of antibody in 13.3% of samples were higher than 100 mIu/ml and the highest value was 142 mIu/ml. We evaluated anti-HBsAg concentrations in 126 persons 3 months after the third vaccination. The results indicated that 99.2% of them had anti-HBsAg higher than 20 mIu/ml and only one sample was non-protective. 85 Samples (67.5%) had antibody 20–100 mIu/ml and in 31.7% of the cases, the levels of antibody were higher than 100 mIu/ml. Also, the highest value of antibody was 187 mIu/ml. Fig. 1 shows the amount of anti-HBsAg in samples
Fig. 1. The concentration of anti-HBsAg in study group after the second dose of vaccine.
base on gender after the second vaccination. Non-immune participants in males were more than females (41.2% vs. 40.1%). As a result of Fig. 2, anti-HBsAg of more than 20 mIu/ml after third dose vaccine administration was seen in 100% of males and 98.8% of females. Overall, the level of anti-HBsAg in 71.1% of women and 61.2% of men were 20–100 mIu/ml. Also, 28.9% of women and 38.9% of men had Anti-HBsAg higher than 100 mIu/ml. The mean of immunity to HB vaccine in the second (59.5%) and the third (99.2%) administration vaccine was significant (p = 0.001). There was a significant reciprocal correlation between age and anti-HBsAg production in response to second (p = 0.045, R = −0.247) and third vaccination (p = 0.0266, R = −0.325). Besides, there was not a significant difference between the sex and amount of antibody production in response to the second (p = 0.54) and the third vaccination (p = 0.48). 4. Discussion Effective vaccines against HB have become available in 1982. Their widespread use in many areas of the world has dramatically reduced the rate of HB. In Iran, in spite of the availability of an effective vaccine and the incorporation of HBV in to the national infant vaccination program, now it is recommended to be vaccinated high risk adults that were not vaccinated in infancy. It is important to know the rate of protection of HB vaccination in adults. In this study, the concentrations of anti-HBsAg after the second and the third vaccination in high risk adults group were determined and efficacy of vaccine was assessed. We defined anti-HBsAg antibody concentration of 20 mIu/ml as the seropositive threshold, as recommended by ELISA kit instruction. The findings showed that 40.5% of individ-
Fig. 2. The concentration of anti-HBsAg in study group after the third dose of vaccine.
M.H. Baghianimoghadam et al. / Vaccine 29 (2011) 2727–2729
uals had not anti-HBsAg in serum after the second vaccination that recommended there is a need for a third booster immunization to maintain protection in them. In this research, 99.2% of the samples had anti-HBsAg higher than 20 mIu/ml in their serum after the third dose of vaccine. The results indicated that the vaccine of HB is effective, and the boost of HBV vaccine is necessary for adolescents to increase the seropositive rate of anti-HBsAg in adults. Some studies showed that giving a booster dose of HB vaccine to persons who have been vaccinated and the concentration of anti-HBsAg was below 10 mIu/ml could develop a rapid rise in anti-HBsAg antibody [10]. One report has revealed that vaccination at older ages was associated with persistence of higher anti-HBsAg level [11], which supported the effectiveness of booster in adolescents rather than younger age. Lu et al. found that 100% of 15–18 years-old adolescents, after receiving booster dose of recombinant HBV vaccine developed antibody [12]. Immune response rates among health care workers in Hong Kong were examined. There was a good overall response rate of 93.8%, women responding better than men [13]. In the study by Roome et al., Connecticut public safety personnel had been vaccinated using Recombivax HB of 528 individuals, 11.9% were found to have no or inadequate levels of antibody. The frequency of inadequate level of antibody increased significantly with age, from 2.8% among those younger than 30 years to 42.1% among those older than 60 years [14]. A study which was carried out by Chen, demonstrated that after 1984 that the free HBV vaccination program in Taiwan has been provided to the newborns, the HBV infection rate and HBsAg carriers rate decreased. This study demonstrated the protective of public HBV vaccination among university students older than 18 years of age [15]. It was also found that, there was not a significant difference between sex and anti-HBsAg concentration. This means the percentage of male no responders are equal to female participants and anti-HBsAg production is not affected by sexual factor such as feminine hormones. Another finding of our results is the significant differences between age and antibody production. In other words, as age increased, the antibody production decreased. It is known that increasing age is associated with a decline in humoral and cellular immunity to vaccines [16]. 5. Conclusions Our results reinforce the importance of HB vaccine in adolescents and suggest that three dose of HB vaccine is necessary to increase the seropositive rate of anti-HBsAg in adults.
2729
Acknowledgments This work was supported by Shahid Sadoughi University of Medical Sciences. The authors thank Mrs. Laleh Pedram for her technical assistance and Mr. Amin Dehghan for his critical reading and editing of this manuscript. References [1] Mahoney FJ. Update on diagnosis, management, and prevention of hepatitis B virus infection. Clin Microbiol Rev 1999;12:351–66. [2] Beasley RP, Hwang LY, Lin CC, Ko YC, Twu SJ. Incidence of hepatitis among students at a university in Taiwan. Am J Epidemiol 1983;117:213–22. [3] Hammitt LL, Hennessy TW, Fiore AE, Zanis C, Hummel KB, Dunaway E, et al. Hepatitis B immunity in children vaccinated with recombinant hepatitis B vaccine beginning at birth: a follow-up study at 15 years. Vaccine 2007;28: 6958–64. [4] Coleman PJ, McQuillan GM, Moyer LA, Lambert SB, Margolis HS. Incidence of hepatitis B virus infection in the United States, 1976–1994: estimates from the National Health and Nutrition Examination Surveys. J Infect Dis 1998;178:954–9. [5] Kane MA. Global status of hepatitis B immunization. Lancet 1996;14:696. [6] Malekzadeh R, Khatibian M, Rezvan H. Viral hepatitis in the world and Iran. J Irn Med Council 1997;15:183–200. [7] Merat S, Rezvan H, Nouraie M, Jamali A, Assari S, Abolghasemi H, et al. The prevalence of hepatitis B surface antigen and anti-hepatitis B core antibody in Iran: a population-based study. Arch Iran Med 2009;12: 225–31. [8] Poorolajal J, Mahmoodi M, Majdzadeh R, Nasseri-Moghaddam S, Haghdoost A, Fotouhi A. A long-term protection provided by hepatitis B vaccine and need for booster dose: a meta-analysis. Vaccine 2010;28:623–31. [9] Hadler SC, Francis DP, Maynard JE, Thompson SE, Judson FN, Echenberg DF, et al. Long-term immunogenicity and efficacy of hepatitis B vaccine in homosexual men. N Engl J Med 1986;315:209–14. [10] Milne A, Waldon J. Recombinant DNA hepatitis B vaccination in teenagers: effect of a booster at 5 1/2 years. J Infect Dis 1992;166:942. [11] McMahon BJ, Bruden DL, Petersen KM, Bulkow LR, Parkinson AJ, Nainan O, et al. Antibody levels and protection after hepatitis B vaccination: results of a 15-year follow-up. Ann Intern Med 2005;142:333–41. [12] Lu JJ, Cheng CC, Chou SM, Hor CB, Yang YC, Wang HL. Hepatitis B immunity in adolescents and necessity for boost vaccination: 23 years after nationwide hepatitis B virus vaccination program in Taiwan. Vaccine 2009;5: 6613–8. [13] Lim WL, Wong DA, Cheng KC. Immune response to hepatitis B vaccine in health care workers in Hong Kong. HKMJ 1996;2:138–40. [14] Roome AJ, Walsh SJ, Cartter ML, Hadler JL. Hepatitis B vaccine responsiveness in Connecticut public safety personnel. JAMA 1993;270:2931–4. [15] Chen CC, Yen CH, Wu WY, Hu SW, Chen SC, Bell WR, et al. Epidemiology of hepatitis B virus infection among young adults in Taiwan, China after public vaccination program. Chin Med J 2007;5:1155–8. [16] Burns EA, Lum LG, L’Hommedieu G, Goodwin JS. Specific humoral immunity in the elderly: in vivo and in vitro response to vaccination. J Gerontol 1993;48:B231–6.