In a medical research project nearly unrivalled in its ambition and scope, volunteers worldwide are rolling up their sleeves to receive experimental vaccines against the coronavirus – only months after the virus was identified.
Companies such as Inovio and Pfizer have begun early tests of candidates in people to determine whether their vaccines are safe. Researchers at the University of Oxford in England are testing vaccines in human subjects, too, and say they could have one ready for emergency use as soon as September.
Moderna on Monday announced encouraging results of a safety trial of its vaccine in eight volunteers. There was no published data, but the news alone sent hopes soaring. Animal studies have raised expectations, too.
Researchers at Beth Israel Deaconess Medical Center in Boston on Wednesday published research showing that a prototype vaccine effectively protected monkeys from infection with the virus. The findings will pave the way to the development of a human vaccine, said the investigators. They have already partnered with Janssen, a division of Johnson & Johnson.
In labs around the world, there is now cautious optimism that a coronavirus vaccine, and perhaps more than one, will be ready sometime next year. Scientists are exploring not just one approach to creating the vaccine but at least four. So great is the urgency that they are combining trial phases and shortening a process that usually takes years, sometimes more than a decade.
The coronavirus itself has turned out to be clumsy prey, a stable pathogen unlikely to mutate significantly and dodge a vaccine.
"It's an easier target, which is terrific news," said Michael Farzan, a virologist at Scripps Research in Jupiter, Florida.
An effective vaccine will be crucial to ending the pandemic, which has sickened at least 4.7 million worldwide and killed at least 324,000. Widespread immunity would reopen the door to lives without social distancing and face masks.
"What people don't realize is that normally vaccine development takes many years, sometimes decades," said Dr Dan Barouch, a virologist at Beth Israel Deaconess Medical Center who led the monkey trials. "And so trying to compress the whole vaccine process into 12 to 18 months is really unheard-of. If that happens, it will be the fastest vaccine development program ever in history."
More than 100 research teams around the world are taking aim at the virus from multiple angles. Moderna’s vaccine is based on a relatively new mRNA technology that delivers bits of the virus’s genes into human cells. The goal is for cells to begin making a viral protein that the immune system recognises as foreign. The body builds defences against that protein, priming itself to attack if the actual coronavirus invades.
Industrial quantities
Some vaccine-makers, including Inovio, are developing vaccines based on DNA variations of this approach. But the technology used by both companies has never produced a vaccine approved for clinical use, let alone one that can be made in industrial quantities. Moderna was criticised for making rosy predictions, based on a handful of patients, without providing any scientific data.
Other research teams have turned to more traditional strategies. Some scientists are using harmless viruses to deliver coronavirus genes into cells, forcing them to produce proteins that may teach the immune system to watch out for the coronavirus. CanSino Biologics, a company in China, has begun human testing of a coronavirus vaccine that relies on this approach, as has the University of Oxford team.
Other traditional approaches rely on fragments of a coronavirus protein to make a vaccine, while some use killed, or inactivated, versions of the whole coronavirus. In China, such vaccines have already entered human trials.
Ensuring that vaccines are safe and effective demands large trials that require careful planning and execution. If successful vaccines emerge from those trials, someone's going to have to make an awful lot of them. Almost everyone on the planet is vulnerable to the new coronavirus. Each person may need two doses of a new vaccine to receive protective immunity. That's 16 billion doses. "When companies promise of delivering a vaccine in a year or less, I am not sure what stage they are talking about," said Akiko Iwasaki, an immunobiologist at Yale University. "I doubt they are talking about global distributions in billions of doses."
Manufacturing vaccines is profoundly more complex than manufacturing, say, shoes or bicycles. Vaccines typically require large vats in which their ingredients are grown, and these have to be maintained in sterile conditions. Also, no factories have ever churned out millions of doses of approved vaccines made with the cutting-edge technology being tested by companies like Inovio and Moderna.
Pandemic demand
Facilities have sprung up in recent years to make viral-vector vaccines, including a Johnson & Johnson plant in the Netherlands. But meeting pandemic demand would be an enormous challenge. Manufacturers have the most experience mass-producing inactivated vaccines, made with killed viruses, so this type may be the easiest to produce in large quantities.
But there cannot be just one vaccine. If that were to happen, the company that made it would have no chance of meeting the world's demand. "The hope is that they will all, at some level, be effective, and certainly that's important because we need more than just one," said Emilio Emini, a director of the vaccine program at the Bill and Melinda Gates Foundation, which is providing financial support to many competing vaccine efforts. – New York Times Service
