University of Maryland scientists are figuring out what doses of the Ebola vaccine are effective and still safe
Scientists are scurrying to get their Ebola vaccines through the necessary safety trials before they can be used widely. That includes the University of Maryland School of Medicine, which recently kicked off the latest step in their research: figuring out the appropriate dosing for the vaccine that’s both effective and safe.
University of Maryland is one of a handful of institutions involved in the testing of an experimental but promising vaccine developed by the National Institutes of Health’s Vaccine Research Center (VRC) and GlaxoSmithKline (GSK). The hope is that the vaccine will pass through early trials needed by end of December so that the World Health Organization (WHO) and a panel of outside experts can decide whether to move on to a large efficacy trial, which would mean vaccinating a lot of people in West Africa to see how well it works.
The vaccine has already made it through safety trials conducted by the NIH, as well as trials at the University of Oxford and at Emory University. In the current trial, researchers at Maryland vaccinated 10 volunteers on Nov. 10th and 10 volunteers on Nov. 17th. The university has also vaccinated 80 people in Mali. The volunteers’ blood will be monitored for a year, but researchers are most interested in when the participants hit the 28-days post-vaccination mark. That’s when the body should be at its peak antibody response.
“In an ideal world, if we were vaccinating people and there wasn’t an epidemic we would give them two vaccines for full coverage, but since this is an outbreak we want one dose that can protect people,” says principle investigator Dr. Kirsten Lyke. She says they hope that the higher-dose vaccine will be more durable so the effect will last longer. It might not be the best vaccine for long-term protection, but Lyke says a durable single dose will be the best to “jump in” to the outbreak.
Once the university has its data, it will plug its findings into a database that holds information from all the organizations participating in the vaccine trials. Then, the researchers can compare the participants’ overall immune response to those of monkeys.
“The assumption is that if humans make the same quality and amount of immune response as the monkeys, it’s likely that the vaccine [would provide] protection among humans as well,” says Dr. James Campbell, a professor of pediatrics at the University of Maryland Center for Vaccine Development also working on the vaccine. An efficacy trial would be needed to conclude that for sure.
People who are given the vaccine stand no chance of actually getting Ebola from the drug. The vaccine uses an adenovirus (in this case, a type of virus that causes the common cold in chimpanzees) with a gene removed so the virus can no longer multiply. In that gene’s place, scientists put in a single gene from Ebola that expresses a protein that sits on the surface of the virus. It looks like what the immune system would see if a person was actually infected by Ebola, but it doesn’t cause any symptoms. The goal is to trick the immune system into responding, thereby creating antibodies that will protect a person from the actual disease.
Most of the volunteers for the trial have come from the University of Maryland campus, like Andrea Buchwald, a graduate student at the university studying epidemiology. “It seemed like a neat way to contribute to the science and public health effort,” she says.
It’s still early, but Lyke says so far there have been no serious safety concerns. There have been some side effects—Buchwald says she had a fever that “felt really strange, not like a natural fever,” she says, but most side effects have gone away quickly.
As the institution gathers data, it hopes it will meet its end of December deadline to bring the vaccine to the WHO for consideration. The United Nations has already announced that it will not meet it’s Dec. 1 deadline containing the outbreak. A vaccine may ultimately be the one solution to end the outbreak.