The researchers were curious to find out how vaccinating one would affect the incidence of other as both, dengue and Zika, are part of flaviviridae family transmitted through a common mosquito host, Aedes aegypti.
“Vaccinating against one virus could not only affect the control of another virus, it could in fact make it easier for the other to spread,” said Jianhong Wu, a researcher and professor at York University in Toronto, Canada.
The research has been published in the journal Scientific Reports and it identifies a potentially serious public health concern. The study noted that over a third of the world’s population live in areas where dengue is endemic and cases of co-infection with Zika have been reported earlier.
“Recent evidence suggests that dengue virus antibodies can enhance the Zika virus infection. For that reason, we developed a new math model to investigate the effect of dengue vaccination on Zika outbreaks,” Wu said.
The research team’s model showed that vaccinations for dengue increase the number of people contracting Zika. It also showed that the more people in a particular population that are vaccinated against dengue, the earlier and larger the Zika outbreak.
The most effective way to reduce the unintended effect of dengue vaccinations on Zika outbreaks is to develop an integrated strategy that also includes mosquito control.
“We concluded that vaccination against dengue among humans can significantly boost Zika transmission among the population and hence call for further study on integrated control measures on controlling dengue and Zika outbreak,” Yanni Xiao, Professor at Xi’an Jiaotong University in China, said.
Though the researchers pointed out that their findings do not discourage either development or promotion of dengue vaccine products, more work needs to be done to understand how to optimise dengue vaccination programmes and minimise Zika outbreaks risk.
Although vaccines for dengue have been developed and are in use, there is currently no vaccine for Zika.
Source: Zee News