Behind the world’s top drugmakers’ approach to Zika Vaccine

(Bloomberg) — What if a drugmaker spent billions of dollars to create a vaccine — only to find out humans developed natural resistance to the disease before its product is ready?

That is part of the scenario GlaxoSmithKline Plc and other pharmaceutical giants are weighing in their cautious approach to developing a Zika vaccine.

Large portions of the populations in Zika-affected areas could develop immunity to the virus over the next five to 10 years, slowing its circulation into virgin areas, said Moncef Slaoui, chairman of London-based Glaxo's vaccines division. That would make it harder to determine the market for a vaccine, which could be just stockpiled for outbreaks rather than used widely during national immunization campaigns.

Although fear of the virus remains high in the United States and its territories — where almost 300 pregnant women have shown signs of possible infection, according to the Centers for Disease Control and Prevention (CDC) — lawmakers are pushing back on funding to fight it. Glaxo, Merck & Co. and Johnson & Johnson are all moving slowly, in contrast with their reaction to Ebola two years ago, when the drugmakers doubled down on developing a vaccine before their efforts stalled as the outbreak in West Africa waned.

"The notion is not that there is no need for a vaccine" for Zika, Slaoui said. "What's not predictable is how to use this vaccine."

Limited Effect

The World Health Organization declared Zika a public health emergency in February and began an emergency research and development plan for tests, vaccines and drugs. While Ebola is a deadly virus that killed more than 10,000 people in the latest outbreak, Zika doesn't cause serious illness in most infected people. Zika is a major threat mainly to pregnant women, as it can trigger severe birth defects, and is also linked to an increase in cases of a rare neurological disorder.

"While Zika has a high potential impact on women of reproductive age, its limited effect on general health could easily see funding wane, particularly if Ebola saw resurgence or another pandemic threatened," market analysis firm BMI Research said in a May 20 report.

Clinical development will probably take more than three years, Sanofi has said. It took the Paris-based company 20 years to bring its dengue vaccine to market, and the infrastructure it built up during that time makes it easier to begin work on a Zika inoculation.

"We have scientists, clinicians, toxicologists, epidemiologists that understand this family of viruses," said Nicholas Jackson, who heads the Zika vaccine project for Sanofi. "This gives us a great opportunity to move quickly, and quick is needed here."

Human Trials

The U.S. government, meanwhile, is working on a potential vaccine that will enter human trials in September, said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. If it passes safety tests, it will enter effectiveness trials in the first half of 2017. At that point, the timeline will depend on the size of the outbreak the world is facing.

"If there's still a major outbreak, they could have an emergency use of that vaccine and make it available sometime in 2018,'' Fauci said. "Or –-and that's a big or -– if in fact, we don't have a lot of infections, it may take three or more years to prove'' that the vaccine is effective and to win regulatory approval.

While Glaxo, J&J and Merck are among the world's pre-eminent developers and manufacturers of inoculations, they are absent from the list of companies that have shared details with the WHO on vaccine candidates. But all three have emphasized that they are making some early efforts.

Glaxo has said it's evaluating the feasibility of starting a Zika vaccine discovery program and cautioned that vaccine development is a lengthy process, typically taking 10 to 15 years.

J&J is "actively pursuing ways in which our vaccine technology platforms, capabilities and scientific expertise could contribute to the global effort to develop a Zika vaccine," Paul Stoffels, chief scientific officer at the New Brunswick, New Jersey-based drugmaker, said in an e-mail. "If our efforts turn out positive, we are absolutely committed to collaborating and contributing to this urgent need."

Merck continues "to work with public health partners to determine how our expertise and capabilities might be useful in helping to accelerate progress towards controlling this public health issue," spokeswoman Pamela Eisele said in an e-mail.

'Data vacuum'

Among the challenges they face is lack of research. Ebola presented a more tangible opportunity than Zika, because there had been more work done in previous outbreaks that laid the groundwork for the development of vaccines. There's simply a "data vacuum" when it comes to Zika, according to Cameron Simmons, professor of microbiology and immunology at the University of Melbourne's Nossal Institute for Global Health.

Some manufacturers may be hesitant to enter the Zika vaccine race because of the uncertainty around public funding in the United States. After the White House requested $1.9 billion, the Senate last week endorsed a $1.1 billion compromise package, and the House of Representatives passed a $622 million plan. The Obama administration, calling it " woefully inadequate," has threatened to veto the legislation.

"This is not seen as a commercial market, at least for the time being," said Marie-Paule Kieny, an assistant director-general at the WHO.

How the current Zika epidemic will evolve is unknown, and the peak of the outbreaks in Cape Verde and Colombia have passed, Kieny said. Cases are also declining in Brazil, she said. People living in the Americas could develop immunity to the virus as others appear to have done in Southeast Asia and Africa, where the virus has long been endemic.

While it's too early to know what the burden of the disease will look like, one thing is clear, Sanofi's Jackson said: The virus is spreading.

"The projections of the spread of Zika are the reason why the WHO declared an emergency and that's the reason today why we are stepping up," he said.

See also:

Zika virus does cause birth defects

Zika mosquitoes: Already in 30 U.S. states

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