Vaccine makers and drug regulators are making plans in case a variant of the CCP virus turns vaccine development into a “cat-and-mouse game.
Just weeks after major vaccine makers received their first regulatory approvals, the new coronavirus variant has forced scientists to retest their vaccine for common-virus pneumonia (COVID-19, or 2019 coronavirus disease) and prepare to adjust the vaccine regimen if the existing vaccine proves to be less effective than expected.
In the meantime, regulators are considering how to expedite new approvals and whether a revised vaccine regimen could be approved without the need for long-term trials, using the seasonal flu vaccine as a reference.
Scientists hope that multiple existing vaccines will still prove effective against the new highly infectious variants found in the United Kingdom and South Africa. Initial laboratory tests at the University of Texas found that the BioNTech/Pfizer vaccine remains effective against one of the most worrisome of the multiple new variants in the UK and South Africa.
However, Andrew Pollard, head of the Oxford Vaccine Group, warned that the vaccine has not been tested against all of the new variants and that more variants are likely to emerge in the future. “In the future we may well find ourselves in a situation where they can evade the immune response.”
Andrey Zarur, CEO of Greenlight Biosciences, a biotech company developing an mRNA vaccine, said it makes sense to design the new vaccine to “prepare for further mutations.
“This way, the new vaccine has a better chance of continuing to protect against new variants,” Zarur said.
BioNTech/Pfizer and Moderna, the first manufacturers to bring an experimental new coronavirus vaccine to market, have an advantage in dealing with mutations. mRNA technology allows the companies to insert a genetic code that has been adjusted to deal with any variation in the new coronavirus, and BioNTech says it can develop a new vaccine within six weeks.
Paul Duprex, director of the University of Pittsburgh’s Center for Vaccine Research, says the “beauty” of mRNA is that it uses “the human body as a factory” to make the proteins needed to trigger an immune response.
For other vaccine manufacturers, who rely on a different technology, the production process would be more time-consuming. Designing a new protocol for the adenovirus-based Oxford/AstraZeneca vaccine would take only a few days, but getting it into production would take much longer, Dr. Pollard said.
What takes time, he says, “is the production process-designing a new seed, putting it into a production facility, and then producing millions of new vaccine formulations.”
Geoffrey Porges, an analyst at SVB Leerink, an investment bank that focuses on the healthcare industry, estimates that the entire process of designing an mRNA vaccine to vaccination takes three to six months. He said it takes six to eight months for adenovirus vector vaccines from companies such as Oxford/AstraZeneca and Johnson & Johnson, and up to nine months for recombinant protein vaccines developed by companies such as Novavax and Sanofi/GlaxoSmithKline (Sanofi/GSK).
Sanofi told the Financial Times that “if we need to respond to a new strain, the development steps to cover the new strain will take longer compared to the mRNA technology route.” Sanofi is already behind, having developed a vaccine that has failed to generate a strong immune response in older populations.
Vaccines that rely on the use of inactivated or attenuated viruses – such as those produced by China’s Sinopharm and Sinovac – will also take longer to adapt to new variants. Neither Sinopharm nor Kexing responded to a request for comment.
The timing also depends on what regulators require for approval of the adapted vaccines. The European Medicines Agency has said they are already discussing what the requirements should be if changes need to be made. The U.S. Food and Drug Administration (FDA) said it will continue to watch for mutations in the virus that would reduce the effectiveness of the vaccine.
Both regulators told the Financial Times that flu vaccines are adjusted annually to keep up with the most prevalent strains, which could provide a model for a fast-track approval process.
“We do this every year with the flu vaccine.” Angela Rasmussen, a virologist at Georgetown University (Georgetown), said, “We don’t need to do large clinical trials to make sure they work, but flu vaccines have also been around for much longer than the new crown vaccine .”
In normal trials, the effectiveness of the vaccine is judged by whether participants who receive the vaccine are less likely to become infected than those who receive a placebo. To skip that step, scientists may need reliable immune system markers to assess whether a person has the ability to fight the disease. One example is how many antibodies are needed to neutralize the virus, Rasmussen said.
Peter Hotez, a vaccine expert at Baylor College of Medicine, said the FDA should provide more guidance on what studies are needed for an adjusted vaccine to be approved so that research and development companies don’t have to “duplicate efforts unnecessarily.
In the long run, he said, the problem could be solved by a universal coronavirus vaccine designed to provide at least some protection against the entire coronavirus family, including the SARS coronavirus and the Middle East Respiratory Syndrome (Mers) coronavirus.
Recently, the U.S. National Institutes of health (US National Institutes of Health) invited researchers to apply for funding to develop a vaccine for coronaviruses that could develop into a pandemic. But this will be a huge challenge, as many scientists have been trying to create a universal flu vaccine for decades. Some breakthroughs have been made in the past five years, but two clinical trials last year both ended in failure.
Until then, if the new coronavirus does undergo a mutation that could reduce the vaccine’s effectiveness, companies working on mRNA will have an advantage in a vaccine market that could be worth more than $10 billion a year.
“I don’t think at all that the big companies want a bad virus.” SVB Leerink’s Boggs said, “but it does fundamentally change the commercial value of the opportunity.”
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