School of Medicine,University of Sao Paulo and LIM01-HCFMUSP,Sao Paulo,Brazil.
Germany g Department Public Health and Clinical;Heidelberg Institute of Global Health,University of Heidelberg.
Epidemiol Infect. 2019 Jan;147:e196. doi: 10.1017/S0950268819000712.
We present a model to optimise a vaccination campaign aiming to prevent or to curb a Zika virus outbreak. We show that the optimum vaccination strategy to reduce the number of cases by a mass vaccination campaign should start when the Aedes mosquitoes' density reaches the threshold of 1.5 mosquitoes per humans, the moment the reproduction number crosses one. The maximum time it is advisable to wait for the introduction of a vaccination campaign is when the first ZIKV case is identified, although this would not be as effective to minimise the number of infections as when the mosquitoes' density crosses the critical threshold. This suboptimum strategy, however, would still curb the outbreak. In both cases, the catch up strategy should aim to vaccinate at least 25% of the target population during a concentrated effort of 1 month immediately after identifying the threshold. This is the time taken to accumulate the herd immunity threshold of 56.5%. These calculations were done based on theoretical assumptions that vaccine implementation would be feasible within a very short time frame.
我们提出了一个模型,旨在优化疫苗接种活动,以预防或控制寨卡病毒的爆发。我们发现,为了通过大规模疫苗接种活动减少病例数量,最佳的疫苗接种策略应该在伊蚊密度达到每 1.5 人一只蚊子的阈值时开始,此时繁殖数超过 1。引入疫苗接种活动的最长等待时间是在首次发现寨卡病毒病例时,尽管这不如在蚊子密度越过临界阈值时那么有效,可以最大限度地减少感染人数。然而,这种次优策略仍将遏制疫情的爆发。在这两种情况下,追赶策略都应该旨在在识别出阈值后立即集中精力开展为期一个月的接种活动,至少为目标人群接种 25%的疫苗。这是积累 56.5%群体免疫阈值所需的时间。这些计算是基于疫苗接种在极短时间内实施是可行的理论假设做出的。