More than a dozen experts have developed an ethical framework for clinical trials for a Zika vaccine, including UPMC Magee-Women’s Hospital’s chief medical officer Richard Beigi.
“In general, pregnant women have been excluded from research,” said Beigi, who is also an obstetrics and gynecology professor at the University of Pittsburgh School of Medicine and specializes in reproductive infectious diseases.
There are widespread fears among researchers about the possible impacts of testing pharmaceuticals and vaccines on pregnant women because of potential impacts to the fetus, he said.
Spread primarily through infected mosquitos, the Zika virus can cause a range of birth defects known collectively as congenital Zika syndrome. Symptoms include microcephaly, characterized by a smaller than average brain, and damage to the eyes, muscles and joints, but how or when the fetus becomes affected is still unknown.
The National Institutes of Health are currently conducting a Phase II clinical trial for an experimental DNA vaccine to protect against the Zika virus. The goals of the trial are to evaluate the vaccine’s safety and to determine if it provides immunity to Zika. Pregnant women are not enrolled in the clinical trial.
“There’s little to no research when products are put on the market, and then pregnant women use them, either inadvertently – they don’t know they’re pregnant – or we have to use them," Beigi said, referring to vaccines of any kind. "We have less data than you would have on the general population.”
He said when it comes to most vaccines, many fears are unfounded, because the vaccines are not likely to impact a pregnancy. Live attenuated vaccines, which are alive with reduced virulence, could.
For example, some women who are trying to conceive have been advised to first get a measles, mumps and rubella vaccine (MMR) booster, because the MMR vaccine is live attenuated. But Beigi said there’s no evidence that giving a pregnant woman the MMR vaccine would harm the fetus.
“That’s never been proven, that’s more of a theory,” he said. “If there is a prospect of direct benefit to the mom and/or the baby and the risk is minimal, then it is our belief that women should be allowed to consider participation in that trial and consent to participate like anybody else.”
Vaccine research, as well as research investigating other aspects of the Zika vaccine, is also happening at Pitt, through its Cura Zika initiative. Announced last May, the initiative is a joint project of the Pitt Graduate School of Public Health and the Brazilian Ministry of Health. Areas of study include vaccine development, understanding how the virus causes disease and ways to diagnose the presence of the virus in the human body.
The virus is primarily concentrated in Central and South America, though there have been instances of local transmission in Florida and Texas.