Focus on Brazil: In pursuit of the Zika vaccine
The Zika virus seems to have come out of nowhere, jumping from nascent stages of transmission to threatening almost all of the Americas with its spread. Borne by mosquitos, Zika viral infection has led to almost 4,000 babies in Brazil being born with microcephaly, a congential disease which leads to abnormally small heads in newborns. In 2014, Brazil saw less than 150 cases of the condition.
Where did the Zika pandemic come from?
Zika was first discovered almost 70 years ago in Ugandan forest, but, until now, most people living outside of countries where Zika virus is endemic have never heard of it. However, given the suspected connection between Zika and congenital microcephaly, Zika has grabbed the world’s attention.
Explaining the relative obscurity of the disease, Nuno Antunes, an analyst at Decision Resources Group told BioPharma Dive: “Zika virus has never been considered a major health threat. Normally, it was associated with minor pain and not considered any worse than a common cold. Most people never knew if they had it. Now that it’s associated with microcephaly, it has become a major concern, and the fact that it’s so easily transmitted is a real problem.”
The implications of Zika are potentially devastating
The main viral vector for the Zika virus is the Aedes mosquito, although, in the U.S., the virus can also be transmitted by the Asian Tiger mosquito. Zika viral infection has now spread to 23 countries in Latin America and the Caribbean. It currently is an infectious threat to all of the Americas, with the exception of Chile (because of the natural barrier provided by the Andes Mountains) and Canada, protected by its colder climate.
Although it’s mainly a concern for pregnant women, or women who may become pregnant, Zika can infect anyone. There is some evidence to suggest that it may also be sexually transmissible. No treatments or vaccines are currently available.
According to Dr. Antunes, “The impact of this disease in Latin America will be significant, and it will be directly linked to the ability of the governments to control the vector, and down the road, to find a vaccine for the disease. Most of the affected children will never be able to become independent, and are at the risk of suffering important mental impairments.”
The impact of the Zika virus will also have serious economic impacts for the countries affected, as controlling the epidemic will require government intervention. “This will require heavy economic and social efforts; there will be direct expenditures associated with their care, but also a significant economic and social impact as they will require a full-time care taker, most likely a parent who will have to stop working to do so given that these countries are not prepared to offer support to so many children," Antunes said.
At the same time, tourism to areas affected may drop as people plan travel elsewhere. "The travel advisories being issued around the world by entities such as the North American CDC will also bring economic consequences, since they may impact the income that many regions receive from tourists. This impact may prove particularly important in Brazil, who is hosting the 2016 Olympics in August, an event that was expected to bring millions in revenue to the country.”
The need for a vaccine
Right now, the only protection against Zika is adherence to stringent guidelines, including not traveling to Zika-endemic places, or if you happen to be there, wearing mosquito repellant and long-sleeved shirts, and sleeping in air conditioned, screened rooms at night.
U.K.-based Oxitec has developed a technology to genetically modify the mosquitoes carrying Zika so they pass along a self-destruct gene in their offspring. This technique was previously used to combat the Dengue virus and proved somewhat effective, but Dr. Antunes does not see this as a long-term solution.
“The only way to eliminate the virus is to eliminate the mosquito. That’s very difficult—if not impossible. So given that, a vaccine would be the ideal solution at this point.”
Brazilian health authorities issue a call-to-action
Anvisa, the Brazilian equivalent of the FDA, has guaranteed any product contributing to the diagnosis, prevention, or treatment of Zika will be granted priority review. In addition, Instituto Butantan, the largest immunobiologicals and biopharmaceutical company in Latin America announced it is looking for pharmaceutical partners to collaborate on a vaccine.
GlaxoSmithKline (GSK) and Sanofi are likely to become involved in any international vaccine efforts. Sanofi recently made history by developing and introducing Dengvaxia, the world’s first vaccine against the dengue virus—one that killed 22,000 people last year. Dengvaxia was approved by Mexico, the Philippines, and Brazil in December 2015.
What are the criteria for rapid approval in Brazil?
Dr. Antunes outlined what Anvisa is looking for in a fast-track therapeutic candidate.
"Some of the characteristics that are seen positively for new treatments looking to register in Brazil are that they can be used for rare, neglected or reemerging diseases," said Antunes.
"Other criteria include being able to be developed through public private partnerships (Parcerias de Desenvolvimento Produtivo)," he said. "And that they are drugs or biologics, which use exclusively raw materials produced by national manufacturers; or that they are drugs or biologics, which are completely developed in Brazil.
"Any of those characteristics will give the minimum number of points that is required to receive prioritized review, which should take approximately three months. Although in reality, it could take longer.”
Collaborative, humane, and potentially profitable
During pandemics, the spirit of collaboration tends to increase. The stakes are high across the board. Not only is Zika a threat to unborn babies in Brazil, but its potential to spread across the world is very real. The potential costs could be significant to public health and economies.
At the same time, for pharma companies involved in vaccine development, there is an opportunity to introduce a new blockbuster in an increasingly important therapeutic category. For example, Dengvaxia is on pace to generate $1.4 billion in revenues by 2020, according to Bloomberg.