McMahon B J, Beller M, Williams J, Schloss M, Tanttila H, Bulkow L
Alaska Native Medical Center, Indian Health Service, Anchorage, USA.
Arch Pediatr Adolesc Med. 1996 Jul;150(7):733-9. doi: 10.1001/archpedi.1996.02170320079014.
To stop an epidemic of hepatitis A in rural Alaska by mass immunization of susceptible persons with 1 dose of an inactivated hepatitis A vaccine.
Nonrandomized, uncontrolled trial. Hepatitis A vaccine was offered to all persons in susceptible age groups in villages with documented cases of hepatitis A. Immune globulin was not offered at the time of vaccination.
Twenty-five rural communities located in interior Alaska and along the northwest coast of the Bering Sea and Arctic Ocean.
Persons without a history of acute hepatitis A in age groups selected by applying results of a previous serosurvey conducted on serum collected before the epidemic.
One dose of a formalin-inactivated hepatitis A vaccine was given to each participant. Adults 20 years of age and older received 1440 enzyme-linked immunosorbent assay units and persons younger than 20 years received 720 enzyme-linked immunosorbent assay units. Prevaccination and postvaccination levels of antibody to hepatitis A IgG were obtained from 136 participants.
An active surveillance system was established to detect persons with symptomatic illnesses compatible with hepatitis A; persons who met the illness criteria were tested for antibody to hepatitis A IgM. One area (the Kotzebue region), where all communities were offered vaccine, was selected for intensive surveillance and analysis.
During the 12-month period before the vaccine trial, 529 cases of icteric hepatitis A were reported, and 443 were confirmed to be positive for antibody to hepatitis A IgM. Hepatitis A vaccine was administered to 4930 persons, 3517 of whom were younger than 20 years. After vaccination began, 237 persons positive for antibody to hepatitis A IgM were identified during a 60-week surveillance period; 46 were vaccines and 191 were unvaccinated susceptible persons. In the Kotzebue region, in communities in which more than 80% of persons considered susceptible were vaccinated, the outbreak ceased in 4 to 8 weeks, whereas in 1 large community in which less than 50% of susceptible persons were vaccinated, the outbreak continued for more than 50 weeks. More than 90% of seronegative persons developed antibody to hepatitis A IgG 3 to 4 weeks after vaccination.
This trial suggested that by providing both short-term and long-term protection, hepatitis A vaccine used without immune globulin halted an established epidemic of hepatitis A in rural Alaska.
通过对易感人群接种一剂甲型肝炎灭活疫苗来阻止阿拉斯加农村地区的甲型肝炎流行。
非随机、无对照试验。向有甲型肝炎确诊病例的村庄中所有易感年龄组的人群提供甲型肝炎疫苗。接种疫苗时不提供免疫球蛋白。
位于阿拉斯加内陆以及白令海和北冰洋西北海岸的25个农村社区。
根据在疫情暴发前采集的血清进行的既往血清学调查结果选定年龄组中无急性甲型肝炎病史的人群。
给每位参与者接种一剂甲醛灭活的甲型肝炎疫苗。20岁及以上的成年人接种1440酶联免疫吸附测定单位，20岁以下的人接种720酶联免疫吸附测定单位。从136名参与者中获取接种疫苗前和接种疫苗后甲型肝炎IgG抗体水平。
建立主动监测系统以检测有符合甲型肝炎症状性疾病的人；符合疾病标准的人检测甲型肝炎IgM抗体。选择一个所有社区都接种了疫苗的地区（科策布地区）进行强化监测和分析。
在疫苗试验前的12个月期间，报告了529例黄疸型甲型肝炎病例，其中443例经确认甲型肝炎IgM抗体呈阳性。4930人接种了甲型肝炎疫苗，其中3517人年龄小于20岁。开始接种疫苗后，在60周的监测期内发现237人甲型肝炎IgM抗体呈阳性；46人是接种了疫苗的，191人是未接种疫苗的易感人群。在科策布地区，在超过80%的易感人群接种了疫苗的社区，疫情在4至8周内停止，而在一个易感人群接种率低于50%的大社区，疫情持续了50多个星期。超过90%的血清阴性者在接种疫苗后3至4周产生了甲型肝炎IgG抗体。
该试验表明，通过提供短期和长期保护，不使用免疫球蛋白的甲型肝炎疫苗阻止了阿拉斯加农村地区已有的甲型肝炎流行。
