The rapid spread of the zika virus across the Americas has spurred research bodies and pharmaceutical companies to start the hunt for a cure, but the financial incentive and likely length of time for a vaccine to be developed are unclear.
Cases of the virus, which has appeared in countries across the Americas and the Caribbean, have already been reported among travelers returning to the U.S. An article in The Lancet medical journal this month warned that in wetter and warmer parts of the U.S., mosquitoes could carry the virus from infected travelers and spread it to other people.
According to researchers led by Kamran Khan of St. Michael's Hospital, Toronto, about 200 million Americans — more than 60 percent of the U.S. population — live in areas of the country where mosquitoes could spread zika during warmer months. A further 22.7 million people live in humid, subtropical parts of the country, including southern Texas and Florida, which might support the spread of zika all year around.
That, coupled with reports of a correlation between zika and birth defects and still-fresh memories of the recent ebola epidemic have spurred the Brazilian and U.S. governments to commit to working together to find a vaccine.