NY Travel Clinic

Brazilian Researchers Join With U.S. in Hunt for Zika Vaccine

More than a dozen drug companies already looking for a solution, which is likely several years away

SÃO PAULO—A leading Brazilian biomedical research center is teaming up with the U.S. and the World Health Organization in the latest effort to develop a vaccine for the mosquito-borne Zika virus.

The Butantan Institute here has said it would partner with a division of the U.S. Department of Health and Human Services to develop the new vaccine for the virus, which spread across the Americas and raised concerns ahead of next month’s Rio Olympics Games in Rio de Janeiro.

The U.S. division, known as the Biomedical Advanced Research and Development Authority, or Barda, will supply initial funding of $3 million for the project. The funds will be invested in equipment and other research-related areas, according to officials.

Most medical authorities agree that a Zika vaccine remains years away. Development will require several phases of testing on animals and humans.

Through May 28 of this year, Brazil has had 161,241 cases of Zika, which the World Health Organization has classified as a public health emergency. More than 38,000 cases have been registered in Rio de Janeiro state, more than in any other state except Bahia in the northeast. The reporting of Zika cases became mandatory in Brazil at the beginning of this year. Zika cases have been reported in 60 other countries and territories, including the Puerto Rico, American Samoa and the U.S. Virgin Islands.

Medical authorities say there is a causal link between the virus and a surge in brain abnormalities in fetuses and infants of women who were infected during their pregnancies. They include cases of a rare neurological condition called microcephaly, in which that causes babies are born with undersized skulls and brains. Authorities also believe that Zika is related to an uptick in cases of the rare nervous system disorder Guillain-Barré syndrome.

The quest for a vaccine has acquired urgency as the virus transmitted by the Aedes aegypti mosquito has migrated from Africa across Asia and the Pacific islands to the Western Hemisphere over the last several years. At least 15 drug companies already are working to develop a Zika vaccine, according to WHO.

The idea of Brazil and the U.S. creating a joint high-level project to develop a vaccine emerged from a phone conversation in January between U.S. President Barack Obama and Brazilian President Dilma Rousseff, who has since been suspended from office while she stands trial on impeachment charges.

Subsequent conversations and meetings between Butantan and BARDA officials led to assembling a team of researchers and a set of research conditions for developing an inactivated vaccine, using virus particles that can’t replicate.

Much has remained mysterious about the Zika virus since it was first isolated in the late 1940s. Until recently it was regarded as a mildly irritating affliction that often produced no symptoms in humans or only relatively minor ones such as skin rashes, eye redness and joint pain. But it has shown a formidable ability to mutate and produce serious new complications as it travels across the globe.

That mutative capability poses challenges for medical researchers trying to develop a vaccine, said Peter Hotez, dean of the National School of Tropical Medicine at the Baylor College of Medicine in Houston and president of the Sabin Vaccine Institute. Dr. Hotez said particular care will be needed to develop a vaccine that won’t pose risks to one principal target population: pregnant women and their unborn babies.

“That’s about the highest bar there is from a regulatory-hurdle perspective,” Dr. Hotez said. “So there’s going to have to be lots of studies showing that the vaccine is safe for using in pregnancy.”

Extensive safety studies also will have to be done to make sure the vaccine doesn’t produce Guillain-Barré syndrome, he added.

“That’s all a long way of saying you’re not going to have the Zika vaccine licensed, I don’t think, for several years, certainly not in time for this current outbreak in the Americas,” Dr. Hotez said.