Interpretation and consideration of “Substitution of in vivo method(s) by in vitro method(s) for the quality control of vaccines” in General Texts of European Pharmacopoeia / 中国生物制品学杂志

Interpretation and consideration of “Substitution of in vivo method(s) by in vitro method(s) for the quality control of vaccines” in General Texts of European Pharmacopoeia@#Potency is a critical quality attribute for controlling relevant biological properties and batch consistency of vaccines.The methods can be divided into in vivo and in vitro methods according to whether animals are used.The in vivo methods are large consuming of animals and time,as well as have large variant detection results.In contrast,the in vitro alternative methods have been the hotspot of research due to their simple operations,in line with 3Rs principles,and more stable results.However,owing to the complexity of experimental design and the lack of corresponding guidance,the research progress of alternative methods is slow.Recently,“Substitution of in vivo method(s) by in vitro method(s) for the quality control of vaccines” was adopted in the European Pharmacopoeia(10th Edition),which clarifies the critical points of consideration for substitution.This paper interprets the chapter and puts forward some thoughts on that in China,which is expected to speed up the alternative methods research and improve the ability of vaccine quality control and supervision in China.

Dynamic change of mother-source neutralizing antibodies against enterovirus 71 and coxsackievirus A16 in infants / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Enterovirus 71 (EV71) and coxsackievirus A16 (Cox A16) are major causative agents for hand, foot and mouth disease (HFMD). Studies indicate that the frequent HFMD outbreaks result in a few hundreds children's death in China in recent years. The vaccine and other research for HFMD need to be developed urgently.</p><p><b>THE AIMS OF OUR STUDY WERE</b>to explore dynamic development of mother-source neutralizing antibodies against EV71 and Cox A16 in infants from Jiangsu Province, China, and to provide the fundamental data for further establishing of corresponding immunization course.</p><p><b>METHODS</b>Peripheral blood samples were collected from 133 of parturient women once immediately before delivery and their infants at two and seven months of age. Method of micro-dose cytopathogenic effect was used to measure neutralizing antibodies against EV71 and Cox A16, respectively.</p><p><b>RESULTS</b>Seropositive rates of anti-EV71 and anti-Cox A16 in prenatal women were 79.7% (106/133) and 92.5% (123/133), respectively; geometric mean titers (GMTs) were 29.0 and 61.9; 75.9% (101/133) prenatal women were both positive in anti-EV71 and anti-Cox A16; seropositive rates of anti-EV71 and anti-Cox A16 were 25.6% (34/133) and 38.3% (51/133) in infants at two months of age; GMTs were 12.3 and 18.0, respectively. GMTs of anti-EV71 were significantly higher for infants at seven months (82.6) compared with that at two months (P < 0.05), showing infants had inapparently infected by EV71 during two to seven months. Although only one offspring (0.75%) at seven months was found having anti-Cox A16 transfered from maternal, this observation suggested no maternal antibody may remain in infants at seven months.</p><p><b>CONCLUSIONS</b>The prevalence of EV71 and Cox A16 were relatively high in Jiangsu Province. Bivalent vaccine against both EV71 and Cox A16 should be developed, and the ideal time point for prime immunization for infants is around 2-5 months of age.</p>

Genetic characterization of enterovirus 71 complete genome isolated in Beijing, 2008 / 中华流行病学杂志

Objective To investigate the characterization of the complete genome of EV71 in Beijing, 2008 and to provide basis for selecting appropriate virus strain to develop vaccine. Methods 12 throat swab samples were collected from children with hand-foot-mouth disease (HFMD). One sample named 08YM-3 was cultured and isolated in vero cells. Viral RNA was extracted and carried out by RT-PCR and 5' , 3' rapid amplification of eDNA ends (RACE) to obtain the sequence from 08YM-3. PCR products were cloned and analyzed. Nucleotide identity between sequences was calculated and sequence alignments were made to generate phylogenetic trees using MegAlign in DNAStar. Results 3 clones were constructed that covered EV71 complete genome. Data from sequences analysis showed that this viral strain named BJ08 shared 95.6%-96.7%, 88.3%-96.1%,78.1%-94.0%,90.8%-94.6%, 85.9%-94.1% and 90.9%-93.9% in 5' UTR, PI, P2, P3, 3' UTR region and complete genome with C4 subtype, respectively. B J08 showed low nucleotides identity (<90%) with other subtypes. Phylogenetic trees established from alignment of the complete genome and VPI region indicated that B J08 belonged to C4 subtype. BJ08 and C4 subtype strains shared the same amino acids in 6 sites in VP1 region, which were associated with EV71 subtype. There was no mutation in VP1 antigen epitope (92-107aa). Conclusion This BJ08 strain belonged to C4 subtype. Further study on EV71 complete genome would have great significance for vaccine research.

Evaluation on the analytical sensitivity of 31 HBsAg enzyme immunoassay kits / 中华流行病学杂志

Objective To study the analytical sensitivity on 31 HBsAg enzyme immunoassy (EIA) test kits.Methotis Thirty one HBsAg EIA kits produced by domestic or overseas manufactories and applied for approval during May 2007 to May 2008,were evaluated using the national reference panels.The hyperbolic curve of the log A value and log concentration for the national sensitivity standards was established.The cut-off value of each kit was substituted into the curvilinear equation to determine the analytical sensitivity which was compared between different HBsAg EIA kits.Results Twenty seven(351 lots) domestic and 4(27 lots) overseas kits were compared.Among 378 lots of the 31 HBsAg EIA kits,only 2 lots of the domestic kits had a lower sensitivity when tested with the national HBsAg reference panels,with an average approvalr ate of 99.43%(349/351).The mean analytical sensitivity of the domestic kits for adr,adw,ay serotypes were 0.307,0.419,0.513 ng/ml,respectively.There was a significant difierence between serotypes (F=97.30,P<0.01).The mean analytical sensitivity of the overseas kits for adr,adw,ay serotypes were 0.054,0.066,0.050 ng/ml respectively,with no significant difference between serotypes(F=0.65,P>0.05).The analytical sensitivity of the overseas kits for all the three serotypes was higher than that of the domestic kits(P<0.01).There was no significant difference found between the analytical sensitivities of the kits produced by the same manufactory using 30- or 60- minute incubation of detection(P>0.05).In contrast,there was significant diffefence noticed between the analytical sensitivities of the kits produced by the same manufactory when tested for 10 or 15- minute coloration of the results(P<0.01).Conclusion Analytical sensitivity of the HBsAg EIA domestic kits should be further improved,especiatry for detecting adw and ay serotypes.

Cellular immune responses of recombinant hepatitis B(rHB)vaccine and HBsAg derived from Hansenular polymorpha cells / 中华流行病学杂志

Objective To study the kinetics of immune response in mice and human immunized with rHB vaccine or rHBsAg derived from yeast cells(Hansenula polymorpha).Methods With different doses,the level of IFN-γ secreted by spleen mononuclear cells(MNC)including CD8+T cells by MACs of mice were detected by enzyme-linked immunospot(ELISPOT)methods after stimulation in vitro with HBsAg MHC class Ⅰ peptide S28-39,respectively.At serial time points.the immunized mice were detected for IFN-γ by ELISPOT as above and for the lymphocytotoxicity test(CTL)by specific lysis assay.The levels of IFN-γ,IL-2,IL-5 and anti-HBs in mice induced by rHB vaccine were detected after single or three doses.Four adults were vaccinated with rHB vaccine according to 0,1 and 2 month schedule.The peripheral blood mononuclear cells(PBMCs)were collected at the 3,8,21,34 and 65 days after the first dose.The CD8+T cells with high purity obtained by sorting from PBMcs were stimulated with rHBsAg or HBsAg peptides.The SFC of IFN-γ,IL-2 and IL-4 of CD4+ and CD8+ T cells were determined by ELISPOT.Results The cytokine of IFN-γ became detectable on day 7 and its peak value appeared on day 14 by ELISPOT.The CTL was detected on day 7 and the maximum lysis of CTL appeared on day 28.The cellular immune response of IFN-γ of MNCs were significantly correlated with the doses vaccinated from 1 μg to 8 μg(Υpositive rates=0.951,Ppositive rates=0.049＜0.05;rSFC=0.996,PSFC=0.000＜0.05).IFN-γSFC of CD8+T cells were significantly associated with the doses from 1 μg to 4 μg(Υ=0.999,P=0.025＜0.05).The HBsAg specific cellular immune and humoral responses of mice immunized with three doses were significantly higher than that with a single dose(P＜0.05).The characteristics of IFN-γ,IL-2 and IL-4 of CD4+ and CD8+ T cells were variable between individuals immunized with the same rHB vaccine.The level of IL-2 and IL-4 of responders were significantly related to the titer of anti-HBs.Conclusion Data from this study showed the kinesis of cellular immunity in mice and adults vaccinated with rHBsAg or rHB vaccine respectively.and the characteristics of cellular immune response in adults induced by the vaccine.Our data provided the basis of standardizing the analysis of cellular immune response to rHB vaccine.

Comparison of the kinesis of immune responses in mice vaccinated by different kinds of recombinant hepatitis B vaccines / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the kinesis of cellular and humoral immune responses to different kinds of recombinant hepatitis B(rHB) vaccines in the immunized mice.</p><p><b>METHODS</b>At serial time points, the levels of IFN-gamma and IL-2 secreted by spleens mononuclear cells (MNC) of the vaccinated mice were detected by enzyme-linked immunospot methods (ELISPOT) after stimulation in vitro with HBsAg MHC class I peptide S28-39 or HBsAg. The lymphocytotoxicity of the immunized mice were also detected (CTL) by a specific lysis assay and the levels of anti-HBs were measured by the Abbott IMX kit.</p><p><b>RESULTS</b>The peak values of IFN-gamma and IL-2 in vaccinated mice were detected by ELISPOT, 10 - 14 days after immunization. The CTL and the level of IFN-gamma induced by rHB vaccine derived from yeast cells (Hansenula polymorpha) (rHP vaccine) were significantly higher than the other two vaccines (P < 0.05). The maximum lysis of CTL appeared in the vaccinated mice on day 10 after immunization, with the percentage of 39.8%. The levels of IL-2 induced by rHP vaccine were significantly higher than the other two vaccines (P < 0.05). However, the IL-2 levels in the rSC (saccharomyces cerevisiae) vaccine group were higher as compared with the rCHO vaccine group at day 7 and day 14 (7 d t = 4.595, P = 0.001 < 0.05; 14 d t = 5.721, P = 0.000 < 0.05) after immunization. The cellular immune response to the rHP vaccine was the strongest while it was the lowest to the rCHO vaccine at day 7 after immunization. The sero-positive rates and the titers of anti-HBs in the vaccinated mice increased with time after vaccination. The titers of anti-HBs in the rCHO vaccine group at day 7 were similar to the rSC vaccine group, but significantly higher than that of the rHP vaccine group (P = 0.044 < 0.05). The anti-HBs titers of the rCHO vaccine group at day 14 were significantly higher as compared to the rSC (P = 0.012 < 0.05) and rHP (P = 0.009 < 0.05) vaccine groups.</p><p><b>CONCLUSION</b>The immune responses induced by the three kinds of rHB vaccines were different in their patterns and levels. According to the intensity of early cellular immune response, the two yeast HB vaccines were superior to the rCHO vaccine, especially to the rHP vaccine. In contrast, the rCHO vaccine induced early seroconversion and high levels of anti-HBs.</p>

Sensitivity and specificity of 4 domestic ELISA kits for detection of hepatitis B virus markers / 中华流行病学杂志

Objective To compare and analyze the sensitivity,specificity of 4 domestic ELISA kits for detection of hepatitis B virus (HBV) markers (HBsAg,anti-HBs,HBeAg,anti-HBe,and anti-HBc).Methods Five hundred and ninety four serum samples collected from patients with chronic hepatitis B and abnormal blood donors were detected for HBV markers and by 4 domestic ELISA kits.Samples with conflicting results by different diagnostic kits were retested.Samples with the HBsAg values close to the cut-off point were detected by Abbott HBsAg confirmation kit (Architect HBsAg confirm).Sensitivity of the kits was determined,using the national sensitivity reference panels for HBsAg,anti-HBs,HBeAg,anti-HBe and anti-HBc.Results The rates of sensitivity on 4 domestic kits for detection of HBsAg were 4 to 10 times lower,and on the 4 domestic kits for detection of anti-HBs,HBeAg,anti-HBc and anti-HBc were 4 to 16 times lower,as compared to Abbott Architect kits.In addition,the domestic HBV ELISA kits had some false positive results.The total coincidence rates of HBsAg,anti-HBs,HBeAg,anti-HBe,anti-HBc were 96.46%-98.15%,94.28%-98.15%,98.15%-99.49%,90.07%-96.30%,92.09%-96.80%,respectively.Conclusion Both sensitivity and specificity of the domestically produced HBV ELISA kits should be improved.

Evaluation of multiplex nucleic acid testing assays for screening of hepatitis B virus DNA in blood donation process / 中华流行病学杂志

Objective To evaluate the multiplex nucleic acid testing (NAT) assays for HBV,HCV and HIV in detecting HBV DNA in plasma samples. Methods 534 plasma samples collected form several areas were detected with Abbott Architect i2000 HBsAg, ani-HBs, HBeAg, anti-HBe, anti-HBc and anti-HBc IgM diagnostic kits. HBV DNA levels of those samples were detected with Roche COBAS AmpliPrep/ COBAS TaqMan HBV Test. Two kinds of multiplex NAT assays for HBV, HCV and HIV were used to test HBV DNA of those 534 samples. Results of serology-markers and quantitative HBV DNA levels with results of NAT were compared. Results HBV DNA was positive in all 81 HBsAg, HBeAg and anti-HBc positive samples,detected by both of NAT assays. HBV DNA was positive in 11 and 19 of 200 HBsAg negative samples when detected with the two kinds of NAT assays separately. Compared with the quantitative results detected by Roche COBAS AmpliPrep/COBAS TaqMan HBV Test, the HBV DNA positive rates were 96.9% and 94.3% in 193 samples of HBV DNA levels over 500 IU/ml while 40.2% and 45.3% in 117 samples of HBV DNA levels below 500 IU/ml while 99.3% and 96.0% in 151 samples of DNA negative HBV. Conclusion There are some occult low level HBV DNA carriers with HBsAg negative results in China. NAT assays for HBV, HCV and HIV may be useful to improve the transfusion safety.

Studies on the status of immune memory after completion of hepatitis B vaccination / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the immune memory in vaccinees after the completion of a full schedule hepatitis B immunization.</p><p><b>METHODS</b>One thousand and two hundred one infants born in 1987 -1989 were immunized with 3 doses of plasma derived hepatitis B vaccine, while 2484 newborn babies during 1996-1999 were injected with 3 doses of the yeast recombinant hepatitis B vaccine. All of the infants under observation were tested for HBsAg, anti-HBs and anti-HBc, in 2005. Of 959 individuals negative for anti-HBs (< 10 mIU/ml), HBsAg and anti-HBc, 228 were immunized with plasma-derived vaccine and 731 with yeast recombinant vaccine after birth. All of them were detected for anti-HBs 15 days after a booster of 10 Ipg yeast recombinant vaccine. In addition, interleukin-2 (IL-2) was detected in 11 non-responders and 22 responders after boostering, using an enzyme-linked immunospot (ELISPOT). The anti-HBs levels of 190 individuals (91 with plasma derived vaccine and 99 with yeast recombinant vaccine) who had had quantitative data on their antibody status after the primary hepatitis B vaccination, were compared with that after the boostering.</p><p><b>RESULTS</b>Among the individuals who received plasma derived vaccine 16-18 years ago, 79.82% of them showed the signs of immune memory after one booster, with a geometric mean titer (GMT)of 325.69 mIU/ml. Of the individuals who received the yeast recombinant vaccine 6-9 years ago, 95.62% showed immune memory after one booster,with its GMT of 745.18 mIU/ml. Anti-HBs levels induced by the booster were associated with that after the primary immunization. The positive rate of IL-2 was 40.91% in subjects with good immune memory. However, IL-2 was not detected in non-responders after the booster (P < 0.01).</p><p><b>CONCLUSION</b>Most of the individuals who had received a completed schedule of primary hepatitis B vaccination and seroconverted from anti-HBs positive to negative,showed the signs of having immune memory after the booster. Only a small proportion of the vaccinees had lost their immune memory during the long term follow-up period, suggesting that these individuals should receive a booster of hepatitis B vaccine in the highly endemic areas of hepatitis B. Hepatitis B virus; Immune memory; Booster immunization</p>

Study on the efficacy of hepatitis B virus vaccination and its influencing factors among children in rural area of Jiangsu province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the efficacy of hepatitis B viruse (HBV) vaccination and its influencing factors among children in rural area of Jiangsu province.</p><p><b>METHODS</b>Twenty-five hundred and twenty-two children born after 1998 in rural area were selected as the study population using multistage cluster sampling method. HBsAg and anti-HBs were detected by enzyme linked immunoassay (ELISA) and radio-immunoassay (RIA), respectively. Anti-HBs negative children were boosted using different hepatitis B vaccines and the efficacy was compared. Factors causing HBV infection in HBsAg positive children were also investigated.</p><p><b>RESULTS</b>HBsAg positive rates in 1-7 year olds were 0.28%-1.28%, and the anti-HBs positive rates decreased from 76.7% to 45.5%. The HBsAg positive rate in children not timely vaccinated was significantly higher than those with HBV vaccine injection within 24 hours after birth (1.4% vs. 0.5%, P = 0.031). More than 90% of the anti-HBs negative children had protective level of anti-HBs after boosted with HBV vaccine.</p><p><b>CONCLUSION</b>HBsAg positive rate in children born after 1998 in rural area of Jiangsu province decreased significantly, with an average of 0.8%. The reason for HBsAg carriage in children might be attributed to mother-to-infant transmission or not timely HBV vaccination.</p>

Study on the kinesis of cellular immunity in adults vaccinated with recombinant hepatitis B vaccine / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the kinesis of cellular immunity in adults who were vaccinated with yeast recombinant hepatitis B(rHB) vaccine and the correlation between cellular and humoral immune responses induced by the vaccine.</p><p><b>METHODS</b>Eight adults were vaccinated with rHB vaccine according to 0, 1,2 month schedule. The peripheral blood mononuclear cells(PBMCs) were collected at the 3, 8, 21, 34 and 65 days after the first dose. The high purity of CD4+ and CD8+ T cells obtained by sorting from PBMCs were restimulated with recombinant hepatitis B surface antigens (rHBsAg) or peptides. The spot forming cell (SFC) of IFN-gamma, IL-2 and IL-4 of CD4+ and CD8+ T cells were detected by enzyme-linked immunospot (ELISPOT).</p><p><b>RESULTS</b>The characteristics of IFN-gamma, IL-2 and IL-4 of CD4+ and CD8+ T cells appeared different after immunization with rHB vaccine. IFN-gamma of CD8+ and CD4+ T cells could be detected early with stable SFC, while the IL-2 and IL-4 of CD4+ T cells appeared late but increased after the second and third dose of vaccination. The positive rate of IL-4 of CD4+ T cells were significantly correlated with the positive rate of anti-HBs, while the SFCs of IL-4 and IL-2 of CD4+ T cells were also significantly related to the titers of anti-FIBs.</p><p><b>CONCLUSION</b>IFN-gamma could be detected early after rHB vaccination in adults, and the positive rates of IL-4 and IL-2 were correlated with that of anti-HBs.</p>

Interruption failure of heptitis B virus vaccination in mother-to-infant transmission and heptitis B virus genotypes and preC/BCP mutations / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the association of heptitis B virus (HBV) genotypes and precore(PreC)/basal core promoter(BCP) mutation with interruption failure of HBV vaccination in mother-to-infant transmission.</p><p><b>METHODS</b>A total number of 208 serum samples were collected from infants and mothers,including 16 infants who had become HBsAg-positive despite a complete and timely course of immunization and another 88 infants successfully protected from mother-to infant HBV transmission. HBV genotypes were determined by type-specific primers PCR method. PreC/BCP mutations were detected by direct sequencing of PCR products, and Clustal W 1.8 software was applied to analyzing the sequences.</p><p><b>RESULTS</b>Of 16 mothers who were having vaccine failure infants, 15 (93.8%) were HBeAg positive and infected with genotype C (15/15, 100%). Among 88 mothers of having children being protected by vaccine, 51 (58.0%) were HBeAg positive, with 45.1% (23/51) of genotype C. The proportion of genotype C in HBeAg mothers of infants with vaccine failure, was significantly higher than that of mothers with vaccine protected infants (chi2 = 14.3, P = 0.003). However, the frequencies of T1762/A1764 mutations had no significant differences between genotype C HBeAg positive mothers with vaccine failure or protected infants (33.3% and 13.3%, respectively, P = 0.4). No A1896 mutation was found in these two groups.</p><p><b>CONCLUSION</b>HBV genotype C might contribute to the immune failure of HBV vaccination in mother-to-infant transmission, while PreC/BCP mutation might not have correlation with it.</p>

Role of mutations on the "hepatitis B virus 'a' determinant hotpoint" to the efficacy of hepatitis B vaccine / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study how hepatitis B virus(HBV) 'a' determinant hotpoint mutations were influecing the hepatitis B vaccine efficacy.</p><p><b>METHODS</b>Primers were designed in HBV conservative region, and the degenerate probes for detecting 16 'a' determinant hotpoint mutations were developed for gene chips. Sensitivity and specificity of the gene chips were evaluated by clone sequencing. Sera of 47 pairs of mothers and infants with immune failure and 323 mothers of children with immune protection of HB vaccine were detected by the gene chips.</p><p><b>RESULTS</b>Result from clone sequencing demonstrated that the gene chips were specific for the detection of 'a' determinant hotpoint mutations. The wild type of HBV was still dominant, with the prevalence of 78.66%, and the mutation frequencies of 126A, 145R, 126S-1, 126S-2, 129H, 144A, and 129R were 11.27%, 5.76%, 5.28%, 4.56%, 1.20%, 0.72% and 0.24%, respectively. The prevalence of 126A mutation was significantly higher than that of other mutations(P < 0.01). No significant differences were found in mother-infant transmission rates of 126A, 126S-1, 126S-2 and 145R variants.</p><p><b>CONCLUSION</b>The currently available hepatitis B vaccine could block mother-infant transmission of 126A, 126S and 145R variants. It appears that there is no need to develop a new hepatitis B vaccine against 126 and 145 variants at present, but the consistent epidemiological surveillance on HBV mutants should be carried out.</p>

Establishment and preliminary application of a gene chip for detection of hepatitis B virus "a" determinant hotpoint mutation / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To develop a gene chip for rapid detection of the "a" determinant hotpoint mutation of hepatitis B virus (HBV).</p><p><b>METHODS</b>Primers were designed in the HBV conservative region, and probes for detecting 126A, 126S, 144A, 145R, 145E, 144A+145R, and 144A+145E mutants were developed for that gene chip. PCR amplification and gene chip technology were optimized. The performance of the gene chip was evaluated by detecting the reference plasmids. Forty five samples of serum obtained from patients with chronic hepatitis B were used to compare the sensitivity of the gene chip and the direct sequencing of PCR products.</p><p><b>RESULTS</b>The oligonucleotide microarray was specific for mutant and native plasmids. The sensitivity of the gene chip was 5 x 10(3)copies/micro l with a high reproducibility. The gene chip could detect minor variants when they were more than 10% among the HBV strains. The positive rates of 126A, 126S-1, 126S-2 detected in the 45 specimens by the gene chip (46.67%, 35.56% and 24.44%, respectively) were higher than those detected by direct sequencing of PCR products (9.00%, 4.44% and 2.22%; P=0.000, P=0.000 and P=0.002, respectively). The sequencing of cloned PCR products demonstrated that the gene chip was specific for the "a" determinant hotpoint mutation detection.</p><p><b>CONCLUSION</b>HBV "a" determinant hotpoint mutations can be detected by oligonucleotide microarray with high sensitivity and specificity, providing a method for large scale screening of the mutants.</p>

Safety and immunogenicity of Bilive combined hepatitis A and B vaccine / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the safety and immunogenicity of the Bilive combined hepatitis A and B vaccine produced by Sinovac Biotech Co., Ltd.</p><p><b>METHODS</b>Samples were selected from first year students of a senior high school (adults group) and first to fifth grade 1-5 students of 3 primary schools (children group). Those who were susceptible to both hepatitis A virus (HAV) and hepatitis B virus (HBV), HAV only or HBV only were assigned to group AB, A and B respectively and were vaccinated with three doses (0, 1 and 6 month schedule) of Bilive combined hepatitis A and B vaccine, inactivated hepatitis A vaccine and recombined hepatitis B vaccine respectively. The dosage for adult group was 500 U hepatitis A antigen and/or 10 micro g hepatitis B surface antigen and the dosage for children group was half the dosage of adult group. The potential adverse effects were observed within 72 hours after vaccination. Serum samples were collected for testing anti-HAV and anti-HBs at month 2 and 7 after the initial dose.</p><p><b>RESULTS</b>The rates of local adverse effects were 0.58% and 2.56% in children AB group and adults AB group and the general adverse effects rates were 9.88% and 5.45% respectively. Both local and general adverse effect rates were not significantly different to the control group. The sero-conversion rate of anti-HAV in children and adults AB group reached 100%, one month after 3 doses. The geometric mean titer (GMTs) reached 33,910 mIU/ml and 23,435 mIU/ml respectively, significant higher than that in control group (group A). The sero-conversion rates of anti-HBs were 97.30% and 96.63%, and GMTs were 103 mIU/ml and 102 mIU/ml in children and adults AB group respectively. No significant difference on sero-conversion and GMT was observed when compared with control group.</p><p><b>CONCLUSION</b>The Bilive combined hepatitis A and B vaccine had good safety profile, and the immunogenicity both on anti-HAV and anti-HBs was similar to that of separated components.</p>