Targeted Vaccination Can Stop Epidemics

March 5, 2018

A study of simulated epidemics has found that targeted vaccinations is more effective than a quarantine or taking no action at all.

The best way to fight an epidemic is through targeted vaccination, according to a study conducted by scientists at the Italian National Research Council and the Joint Research Centre (JRC).

The researchers used physics-based simulations to replicate the way individuals are able to transmit infection to one another and examined several potential strategies to contain an epidemic outbreak. Under the simulations, vaccination produced better results than quarantine or taking no action at all, even when only a small number of people received the relevant shot.

"Targeted vaccination was found to be the best option in nearly all epidemic cases," according to a release announcing the findings.

Quarantine performed the worst of the three options, with scientists noting that strategy quarantine quickly became ineffective after an outbreak. "Quite early on in a simulated outbreak, even the 'do nothing' (nonintervention) strategy becomes preferable to quarantine," the release says.

Using simplified versions of computational frameworks that have been used to study real epidemics, the researchers used “nodes” to represent individuals and created a system in which the nodes would interact with one another similar to the interactions between individuals in the real world.

The most effective option during the simulated epidemics was targeted vaccination. This strategy was based on the concept of optimal percolation and included finding the least set of nodes that can be fragmented into small clusters, when those nodes are removed from the network.

"The idea behind this approach is that fragmenting the network ensures infections are contained within small groups, hence preventing the occurrence of large outbreaks," the release says.

This latest study further illustrates the power vaccines can have in combating the spread of infectious diseases across the globe.