UW-Madison researchers plan next week to start monkey studies of Zika virus, which has caused an outbreak apparently linked to birth defects in Latin America and the Caribbean.
Campus scientists will infect rhesus macaque monkeys with the mosquito-borne virus to examine three questions: how long Zika persists in blood, urine and saliva; if infection protects against future exposure; and whether the stage of pregnancy in which infection occurs impacts the effects on offspring.
“There’s a lot that’s unknown about Zika virus right now. It’s an understudied virus because it doesn’t make people very sick,” said David O’Connor, a UW-Madison pathology professor who is part of the research team.
“We don’t know the basics of how and where the virus replicates, what sort of immune response the body mounts to the virus and under what circumstances the virus causes diseases,” O’Connor said.
The research, funded by the National Institutes of Health, will be conducted in secure facilities at the Wisconsin National Primate Research Center designed for the safe study of potentially harmful viruses.
The findings could help with vaccine development and treatment for Zika virus and inform recommendations by health officials.
“People want clear answers, and we want to be able to make clear public health recommendations,” Thomas Friedrich, a UW–Madison professor of pathobiological sciences, said in a university statement. “There are a lot of countries in the tropics right now saying, ‘Don’t get pregnant until 2018.’ That’s not a sustainable public health recommendation.”
Last month, the Centers for Disease Control and Prevention advised pregnant women not to travel to affected countries, which have seen an uptick in cases of microcephaly, a birth defect in which babies are born with abnormally small heads and often underdeveloped brains.
The National Institutes of Health has made Zika virus research a high priority. Groundwork underway at UW–Madison led to NIH support for three studies of the virus in rhesus macaques, monkeys whose physiology and immune systems are similar to humans, the university said.
A total of 15 monkeys will be used, including six pregnant monkeys, two at each trimester of pregnancy, O’Connor said. Amniotic fluid will be sampled to see if it contains the virus.
“These are experiments that you just can’t do in people,” he said.
Zika does not mutate quickly, so it could be easier to target Zika with a vaccine than HIV, for which no approved vaccine exists, or influenza, which requires annual shots.
But it’s not clear how to best provoke an immune response to Zika, O’Connor said.
“That’s why we need to have data that shows what natural immunity looks like and the sort of immune responses that arise to protect an individual when they encounter that virus again,” he said.
O’Connor was in Brazil for HIV research in October, when the Zika outbreak was first reported. His collaborators there were looking into unusual cases of microcephaly and asked O’Connor to help them look for new viruses.
“At the time we didn’t know it would explode into the public consciousness like it did,” O’Connor says.
UW-Madison pathobiological sciences professor Jorge Osorio and research scientist Matthew Aliota were first to identify the Zika virus circulating in Colombia in October, the university said. They will be joining in the new research, along with Ted Golos, professor of obstetrics and comparative biosciences. He studies how other infections during pregnancy impact newborn health.
O’Connor said Zika was first discovered in macaques in Africa in the late 1940s.
“Since Zika has been around in Africa for 65 years, at least, it begs the question why we’re seeing these disease associations now when we haven’t seen them before,” he said.