Scianna Matteo, Gallotti Riccardo, Tizzoni Michele, Artime Oriol, Alvarez-Zuzek Lucila G
Complex Human Behaviour Lab, Foundation Bruno Kessler, Trento, Italy.
Department of Sociology and Social Research, University of Trento, Trento, Italy.
PLoS Comput Biol. 2025 Aug 11;21(8):e1013274. doi: 10.1371/journal.pcbi.1013274. eCollection 2025 Aug.
Vaccination is vital for preventing disease spread, as demonstrated by its role played in recent outbreaks such as measles, COVID-19, and the 2014 West Africa Ebola crisis. Classical ring vaccination-targeting individuals near infected cases to form protective clusters-has become of interest due to its effectiveness, yet it is strongly influenced by the quality of contact tracing and availability of medical resources. Here, we model the efficiency of a family of ring vaccination-inspired strategies that address these limiting factors and disentangle them from the structure of the contact patterns. In particular, we evaluate scenarios that consider a vaccination radius r, used to vaccinate nodes in the network up to r contacts away (block vaccination) or exactly r contacts away (ring vaccination) from nodes of interest. Each one of these is tested under two further scenarios: the preventive one, where individuals are vaccinated before the epidemic takes place, and the containment one, where vaccination occurs during an outbreak to limit disease spread. They are tested in synthetic networks, where we find that in the preventive scenario, ring outperforms block vaccination, reducing the size of the epidemic and, in some cases, even preventing it from happening. On the other hand, in the containment scenario, we find that both strategies perform slightly similarly in reducing the impact of the diseases but block vaccination using fewer resources. As a case study, the proposed strategies are used to create epidemiological risk maps by employing the spatial position of olive trees in the Salento region in Italy, which recently suffered the impact of the bacterium Xylella fastidiosa.
疫苗接种对于预防疾病传播至关重要，近期麻疹、新冠疫情以及2014年西非埃博拉危机等疫情中疫苗接种所发挥的作用便证明了这一点。经典的环状疫苗接种法是针对感染病例附近的个体进行接种，以形成保护集群，因其有效性而受到关注，然而它受到接触者追踪质量和医疗资源可用性的强烈影响。在此，我们对一系列受环状疫苗接种启发的策略的效率进行建模，这些策略解决了这些限制因素，并将它们与接触模式的结构区分开来。特别是，我们评估了考虑疫苗接种半径r的情景，该半径用于对网络中距离感兴趣节点最多r次接触（块状疫苗接种）或恰好r次接触（环状疫苗接种）的节点进行接种。其中每一种情景都在另外两种情景下进行测试：预防性情景，即个体在疫情发生前接种疫苗；遏制性情景，即在疫情爆发期间进行接种以限制疾病传播。它们在合成网络中进行测试，我们发现在预防性情景下，环状疫苗接种优于块状疫苗接种，可减小疫情规模，在某些情况下甚至能防止疫情发生。另一方面，在遏制性情景下，我们发现两种策略在减轻疾病影响方面表现略有相似，但块状疫苗接种使用的资源更少。作为一个案例研究，通过利用意大利萨伦托地区橄榄树的空间位置，将所提出的策略用于创建流行病学风险地图，该地区最近遭受了苛养木杆菌的影响。
