In battling an epidemic, be armed with vaccine

Last Updated : 31 August 2015, 18:09 IST
Last Updated : 31 August 2015, 18:09 IST

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Last year, scientists launched a trial of an experimental vaccine against Ebola in Guinea. Recently, they reported great news: The vaccine works well, providing remarkable protection just 10 days after injection.

“We have to stop and celebrate the fact that an innovative trial design was able to come up, in the middle of an emergency, with pretty strong results,” said Dr Seth Berkley, the chief executive officer of Gavi, an alliance of public and private organisations that provides greater access to vaccines in developing countries. “Let’s start with that.”

But let’s not end with that. Dr Berkley and other vaccine experts note a grim irony. Scientists showed that this vaccine was effective in monkeys a decade ago. Thereafter, the vaccine lingered in scientific limbo.

“We should have had an Ebola vaccine at least two or three years ago,” said Dr Peter J Hotez, the president of the Sabin Vaccine Institute and a science envoy at the State Department. Only after the West African outbreak exploded last year did fresh urgency push experimental Ebola vaccines into trials. By the time the positive results were published, the outbreak was subsiding.

“After considerable rush and expense, and after thousands of people have died, you now have a vaccine that appears to be pretty damn good,” said Dr Stanley A Plotkin, an emeritus professor of paediatrics at the University of Pennsylvania and a member of the board of the Foundation for Vaccine Research.

We can only guess how many lives might have been saved if this vaccine had passed muster before the outbreak, rather than after. Now Dr Hotez fears that history will repeat itself. Another infectious disease may explode before a promising vaccine is proved safe and effective. “Once again, the world will be caught flat-footed,” he said.

Vaccines are one of the great triumphs of science, but the way that modern medicine functions makes it hard to develop new ones. “That model doesn’t work,” said Dr Hotez. “It hasn’t worked for decades, and it was really brought home with Ebola.”

To make a vaccine, scientists first design experimental forms to test on cells and animals. It may cost $25 million to perform these studies, said Dr Plotkin. The cost of that basic research is typically covered by governments or philanthropies.

Then researchers have to put vaccines through several rounds of trials in humans. In small initial studies, they evaluate its safety and figure out the right dose. In larger studies, they look more closely at its effectiveness and side effects. The cost of taking a vaccine all the way through this process is hundreds of millions of dollars, said Dr Plotkin.

Major pharmaceutical companies can afford to pay for the later stages of vaccine development, said Dr Adel A F Mahmoud, the former president of Merck Vaccines and now a professor of molecular biology and public policy at Princeton. But drug companies are increasingly reluctant to take the risk. “The next step, nobody is touching,” he said.

Part of the problem is that many vaccines offer only modest financial returns, compared with highly profitable drugs for diseases like cancer or heart disease.
“If someone comes to me and says, ‘Give me $500 million to run a product that doesn’t have a market,’ I’m not sure that I can really justify it,” said Dr Mahmoud. “You might do it once, but you’re not going to do it twice.”

Ebola vaccines escaped developmental limbo only after the West African outbreak reached unprecedented proportions and governments began marshaling funds to support trials. “That’s too little too late,” said Dr Hotez.

He and other vaccine experts say we need a more sensible approach, pushing vaccines further through the pipeline before emergencies rather than in the middle of them.

In a recent issue of The New England Journal of Medicine, Dr Plotkin, Dr Mahmoud and Jeremy Farrar, the director of the Wellcome Trust, issued a call for better ways
to get vaccines through the pipeline more quickly.

They proposed the creation of a global vaccine-development fund, supported by governments, pharmaceutical companies and philanthropies.

The authors suggested seeding the fund with $2 billion. “It probably can cover maybe four, maybe five potential products,” said Dr Mahmoud. “It can make a difference.”MERS, a priorityDr Mahmoud and other experts see a number of vaccines that could be pushed forward right now with the support of such a fund. Many say a top priority is MERS, a respiratory virus discovered in West Asia in 2012.

The MERS virus circulates among camels, but it can also spread from person to person in hospitals. While most cases have been reported in Saudi Arabia, a new outbreak flared up earlier this year in South Korea after a businessman returned home from West Asia with an infection.

Dr Hotez warned that fighting in West Asia could allow MERS to spread out of control. “With complete public health infrastructure breakdown in Yemen, that’s one risk of creating a very catastrophic epidemic,” he said.

When it comes to vaccines, MERS is where Ebola was last year. “There are at least two good-looking candidates out there already,” said Dr Plotkin.

But these experimental vaccines have only yielded promising results in animals. Major pharmaceutical companies haven’t stepped forward to carry on the research in humans. Dr Plotkin predicted that a vaccine fund would lead to a MERS trial in humans very quickly.

Two billion dollars may sound like a lot of money to put into vaccines. But Dr Mahmoud points out that nearly $8 billion has been spent coping with West Africa’s Ebola outbreak – not to mention more than 11,000 lives lost.

“If you had a vaccine,” he said, “that total would have been far less.”

Published 31 August 2015, 18:09 IST

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