In most humans, it manifests as a mild, flu-like illness and most people recover within a week.
But a small percentage of people can progress to more severe complications and develop severe symptoms such as haemorrhagic fever, encephalitis, or retinitis.
As yet, no vaccines are available or licensed for human use.
So researchers at the University of Otago Global Health Institute are working with an international consortium, which was recently awarded a $5.7 million Coalition for Epidemic Preparedness Innovations (CEPI) grant, to work on the Rift Valley fever virus.
Institute director Prof John Crump said the illness was transmitted to humans by mosquitoes and contact with infected livestock. Historically, it was a neglected endemic disease in Africa and the Middle East, and its potential to become an epidemic or pandemic had major implications for human and livestock health worldwide, he said.
As climate change expanded the range of mosquitoes, there was a risk RVF outbreaks would become more frequent and widespread, threatening health and livelihoods well beyond traditionally affected areas in Africa and the Middle East.
It meant making a protective human vaccine all the more urgent, he said.
The CEPI grant was given to the Kilimanjaro Clinical Research Institute, in Tanzania, and Otago researchers will help with the RVF epidemiology and modelling to inform vaccine efficacy trials. The New Zealand government was an investor in CEPI and the grant was the first awarded to a coalition involving Otago, Prof Crump said.
"We will be assessing whether it is feasible to do large-scale vaccine trials to both address the disease where it is endemic, whether we can predict epidemics accurately to pre-position vaccine trials and to prepare countermeasures in the event of a spreading epidemic or global pandemic."
