Zika vaccine could take months, years to develop

Researchers trying to find vaccine within next 18 months

Zika has been linked to a disease known as microcephaly, which causes the development of unusually small heads and brain damage in babies.

According to the World Health Organization, the virus has spread explosively to more than 20 countries in South and Central America, and is present in Florida and the Gulf Coast in the United States, and there will be more than 4 million people affected in all of those areas this year.

Researchers and scientists have now entered the fray and are trying to find a vaccine within the next 18 months.

Dr. Joseph Carlin, professor and assistant chair of the Department of Microbiology at Miami University in Oxford, discussed with the Journal-News if a vaccine for the Zika virus can be developed expeditiously.

“It’s unlikely that we’ll have a vaccine that can impact our current outbreak. Up until now, not much attention has been paid to Zika virus, as the infection is typically mild, and only recently has the connection been made with the potential for serious consequences in pregnant women,” he said. “It takes time to develop a vaccine, to test it for safety and efficacy, and to approve it. Then, it would require pharmaceutical companies to scale up production.”

Just like in the 1950s when polio vaccines where developed and waiting to be approved by the government, there are challenges today involved with discovering vaccines.

“There are both technical challenges and policy issues that need to be addressed. From the technical end, we need to know how variable the Zika virus is, and how many varieties of Zika virus exist. If Zika mutates easily, this would present a situation like we see with flu vaccine, requiring continued updates on the vaccine composition,” Carlin said.

He added, “if there are multiple varieties (strains) of the virus, it will increase the challenge of creating a vaccine that protects against all of them. Fortunately, scientists have been developing vaccines against related viruses (West Nile virus, Chikungunya virus and Dengue virus), so we have some familiarity with viruses of this type, and we might be able to apply some of our understanding of those viruses to developing a Zika virus vaccine more quickly.”

Making sure that whatever is finally introduced solves the problem is also very important, Carlin said.

“From a policy perspective, there are questions that need to be answered. Who would get the vaccine? Would it be a live (attenuated) vaccine or a killed vaccine? What is the likelihood that a live vaccine could cause similar effects during pregnancy,” he said. “The last thing we need is a vaccine that causes problems. The medical community is still dealing with the fear of vaccines generated by Andrew Wakefield’s fabricated data that suggested a correlation between the measles vaccine and autism, so rushing an insufficiently tested vaccine out early could be problematic.”

Dr. M. Cameron Hay-Rollins is a professor in the anthropology department at Miami University, and she agrees with her colleague’s assessment regarding the development of a Zika virus vaccine. She told the Journal-News that prevention will be a key to getting rid of the virus.

“Vaccines can take a long time, years sometimes, to develop, and then they have to be tested and produced. Think of the flu vaccine. The CDC makes a decision about the composition of the next year’s influenza vaccine in February,” she said. “It takes months to produce enough vaccine for the flu season each year, and that is for a virus that we know. At this stage, we are still learning about the Zika Virus. The best solution for the near term is prevention of infection.”

Dr. Ginger Cameron, Ph.D., assistant professor of pharmacy practice at Cedarville University, has been following the Zika virus closely. She said testing and time are needed to develop a vaccine that works.

“According to the World Health Organization, we are about 18 months from a Zika vaccine, which is a relatively quick turn around for development of a vaccine,” she said. “Time is needed to learn how to best kill the virus and the best method of vaccination, and we have to test it to make sure it is both safe and effective. We are so accustomed to vaccines that it is easy to forget all the science that goes into development of one.”

Pregnant women have been identified as being at the highest risk of catching the virus, Cameron said, but testing the vaccine on women is a very sensitive matter.

“With Zika, those currently at highest risk are pregnant women, but testing a vaccine on pregnant women is a very complicated matter and cannot be taken lightly,” she explained. “Having time to adequately study the virus and then develop a vaccine and test it is critical. Resources are another challenge. Development of a vaccine can be costly and requires a lab and personnel. This pulls equipment, funding and researchers from other projects/research to refocus on the more immediate threat.”

Ashley Hoehn, Community First Pharmacy manager, believes funding and research are two topics to be considered when talking about developing a vaccine.

“Some of the challenges with developing vaccines is the desire by companies to fund the research for vaccinations. It also takes to time to find a safe, viable vaccine that can work in individuals; this requires initial testing on animal models, then testing on human populations to ensure its safety and efficacy,” she said. “Usually with human studies, it starts with small groups of people and then test population sizes increase. Also, testing the duration of vaccines is important… The other factor is the virus’ ability to mutate.”

Hoehn said that more strains of viruses pop up yearly, and that presents some interesting challenges for researchers and scientists when they look at ways to develop vaccines.

“Every year, there are new strains of viruses, like influenza, that we need to protect against. As for the Zika virus, we already have some research on related viruses like Dengue that has a similar DNA structure,” Hoehn said. “This may help speed up the process of developing a Zika vaccination by already having useful research that can be applied.”

Anna Derksen, 28, of Hamilton County, works in the city of Hamilton. She is currently 26 weeks pregnant and recently learned of the first confirmed case of the Zika virus in Butler County. She doesn’t feel panicked, but is glad information is coming out to warn pregnant women about the dangers to their children the virus can cause.

“I’m not fearful of it, but I know that it is potentially more harmful to my baby than me,” Derksen said. “I’m not worried about contracting it or that it will become an epidemic anytime soon because the disease is in other countries and imported here. But I will take precaution in the spring and summer months when mosquitoes are out. I’ll have my DEET (mosquito repellent) ready.”

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