National Centre in HIV Epidemiology and Clinical Research, Faculty of Medicine, The University of New South Wales, Sydney, NSW, Australia.
Vaccine. 2011 Aug 18;29(36):6125-9. doi: 10.1016/j.vaccine.2011.06.061. Epub 2011 Jun 22.
A trial of the ALVAC-AIDSVAX HIV vaccine was recently found to be partially effective in preventing HIV transmission among study participants in Thailand. The success of this trial means that vaccination may become a viable intervention for the prevention of HIV infection in the medium-term future. Assuming that the vaccine has similar relative protective effectiveness per exposure event for reducing transmission among men who have sex with men (MSM) in high-income settings we investigated the potential population-level impact of rolling out such a vaccine among MSM in New South Wales, Australia. Using a detailed individual-based transmission model that simulates a population of sexually active MSM it was found that one-off intervention of 60% or 30% coverage of a vaccine with characteristics like the ALVAX-AIDSVAX vaccine would likely reduce the cumulative incidence of HIV by 9.6% and 5.1%, respectively, over a 10-year period. Due to the waning of vaccine efficacy, a booster vaccination could be required to maintain this reduction in incidence over the long term. If the previously vaccinated population is given a booster vaccine, with the same protection conferred as with the initial vaccination, every 5 years or every 2 years then the cumulative incidence over 10 years for 60% coverage could be reduced by 14.4% and 22.8%, respectively. Such a weak vaccine, with boosting, may be a potential intervention strategy for the prevention of HIV infection in MSM in high-income countries if further trials show boosting to be safe, acceptable, and cost-effective. However, the moderately low population-level impact suggests that a public health strategy involving such a vaccine should be supplemented with other biomedical and educational strategies.
最近的一项 ALVAC-AIDSVAX HIV 疫苗试验被发现对预防泰国研究参与者中的 HIV 传播具有一定的效果。这项试验的成功意味着，在中期内，接种疫苗可能成为预防 HIV 感染的可行干预措施。假设该疫苗在高收入环境中，每发生一次暴露事件，其对减少男男性行为者（MSM）中的 HIV 传播的相对保护效力与临床试验中观察到的效力相似，我们研究了在澳大利亚新南威尔士州 MSM 中推广这种疫苗的潜在人群层面影响。使用一种详细的基于个体的传播模型，该模型模拟了一群活跃的 MSM，结果发现，一次性干预接种 60%或 30%具有 ALVAX-AIDSVAX 疫苗特征的疫苗，可能分别在 10 年内将 HIV 的累积发病率降低 9.6%和 5.1%。由于疫苗效力的减弱，可能需要加强免疫来维持这种发病率的长期降低。如果以前接种过疫苗的人群接种加强疫苗，且初始疫苗和加强疫苗的保护效果相同，那么每隔 5 年或每隔 2 年接种一次疫苗，那么在 10 年内，60%覆盖率的累积发病率可以分别降低 14.4%和 22.8%。如果进一步的试验表明加强免疫是安全、可接受且具有成本效益的，那么这种具有加强免疫的弱效疫苗可能成为预防高收入国家 MSM 中 HIV 感染的潜在干预策略。然而，这种中度低人群层面的影响表明，涉及这种疫苗的公共卫生策略应该辅以其他生物医学和教育策略。
