Ashur Y, Adler R, Rowe M, Shouval D
Division of Medicine, Hadassah University Hospital, Jerusalem, Israel.
Vaccine. 1999 May 4;17(18):2290-6. doi: 10.1016/s0264-410x(98)00480-0.
Two new hepatitis A vaccines have been developed, and their immunogenicity tested using different immunoassays. The present study was designed to compare the immunogenicity of these two hepatitis A virus (HAV) vaccines--VAQTA and HAVRIX--as determined by seroconversion rates and anti-HAV titers, and using the same immunoassay. Healthy volunteers (15-30 y), seronegative for anti-HAV, were randomized in an open single center study to four groups of 20-21 vaccinees each, to receive either a 25 U or a 50 U dose of VAQTA, or HAVRIX at 720 EU or 1440 EU/dose, administered at 0, 1 and 6 m or at 0 and 6 m, respectively. Four weeks after primary immunization, seroconversion rates were 100% for VAQTA and 95% for HAVRIX, following injection of 50 U or 1440 EU, respectively (p = NS) and anti-HAV GMTs were 40 and 37 mIU/ml for VAQTA and HAVRIX, respectively. At 6 months, prior to the booster dose, seroconversion rates were 100% for both vaccines, with anti-HAV GMTs of 111 and 70 mIU/ml for VAQTA and HAVRIX, respectively (P < 0.05). At month 7, four weeks after the only booster injection, using the two dose regimen, anti-HAV titers were 2212 and 1511 mIU/ml for VAQTA and HAVRIX, respectively (P < NS). Using three doses of 25 U/dose of VAQTA or 720 EU/dose of HAVRIX at 0, 1 and 6 m did not produce any clinically evaluable advantage over the two dose regimen for either vaccine. No significant adverse events were observed using either vaccine. In summary, both vaccines have similar immunogenicity demonstrated using identical immunoassays for evaluation. These results also confirm the outstanding immunogenicity of a single dose of either of the HAV vaccines and support their use in pre- and possibly postexposure prophylaxis against hepatitis A virus infection.
已研发出两种新型甲型肝炎疫苗，并使用不同的免疫测定法对其免疫原性进行了检测。本研究旨在通过血清转化率和抗甲型肝炎病毒（HAV）滴度，并使用相同的免疫测定法，比较这两种甲型肝炎病毒疫苗——VAQTA和HAVRIX的免疫原性。抗HAV呈血清阴性的健康志愿者（15 - 30岁）在一项开放的单中心研究中被随机分为四组，每组20 - 21名接种者，分别接受25 U或50 U剂量的VAQTA，或720 EU或1440 EU/剂量的HAVRIX，分别在0、1和6个月或仅在0和6个月接种。初次免疫四周后，分别注射50 U或1440 EU后，VAQTA的血清转化率为100%，HAVRIX的血清转化率为95%（p = 无显著性差异），VAQTA和HAVRIX的抗HAV几何平均滴度（GMT）分别为40和37 mIU/ml。在6个月时，即在加强剂量之前，两种疫苗的血清转化率均为100%，VAQTA和HAVRIX的抗HAV GMT分别为111和70 mIU/ml（P < 0.05）。在第7个月，即仅进行一次加强注射四周后，采用两剂接种方案，VAQTA和HAVRIX的抗HAV滴度分别为2212和1511 mIU/ml（P < 无显著性差异）。对于任何一种疫苗，在0、1和6个月使用三剂25 U/剂量的VAQTA或720 EU/剂量的HAVRIX相较于两剂接种方案均未产生任何临床可评估的优势。使用任何一种疫苗均未观察到显著的不良事件。总之，使用相同的免疫测定法进行评估表明，两种疫苗具有相似的免疫原性。这些结果也证实了单剂任何一种甲型肝炎疫苗都具有出色的免疫原性，并支持它们用于甲型肝炎病毒感染的暴露前和可能的暴露后预防。
