Zika epidemic to end within two, three years, scientists say
The Zika outbreak raging through Latin American and that has worried people all over the world will likely end and burn itself out in the next two to three years based on the fact that people develop immunity to the virus after an initial infection, according to British scientists.
The researchers predict that populations will eventually develop herd immunity as infections from the mosquito become widespread.
Herd immunity occurs when a high percentage of a population has become immune to an infection either through developing natural immunity or through vaccination, making a wider outbreak less likely. They said that would prevent further transmission of the Zika virus for at least a decade, with only smaller, intermittent outbreaks.
“Because the virus is unable to infect the same person twice – thanks to the immune system generating antibodies to kill it – the epidemic reaches a stage where there are too few people left to infect for transmission to be sustained,” study author Neil Ferguson of the School of Public Health at Imperial College London.
The study was based on mathematical models of the virus, which has been shown to cause microcephaly, a birth defect marked by small head size that can lead to severe developmental problems in babies.
The researchers compared data from Zika’s transmission across Latin America to data on similar viruses, such as dengue, to create a model of projected Zika transmission. They forecast that large-scale transmission will end in two to three years and not resume for a decade.
Similar patterns have been seen in related viral infections, including chikungunya, Ferguson said.
Ferguson said it may be too late to try to control mosquito populations to prevent widespread Zika transmission, and mosquito abatement efforts might delay and prolong the outbreak, which will eventually die out naturally.
“Slowing transmission between people means the population will take longer to reach the level of herd immunity needed for transmission to stop. It might also mean that the window between epidemics – which we predict may be over a decade – could actually get shorter,” he said.
There is no vaccine or specific treatment for Zika yet.
