- Experts believe there will soon be a number of vaccines available to prevent Covid-19
- Although the development process is moving quickly, there are many checks and balances to ensure the final product is safe
- There are, however, concerns about how long a vaccine will remain effective
Americans are ready to rip off their face masks and just have a nice dinner in a restaurant, but the best shot at returning to normalcy – vaccines to prevent Covid-19 – will be in clinical trials for months or longer.
The good news is that there are more than 100 vaccines of varying types and in various stages of development. As of this month, eight of these vaccine candidates were already in early human trials. One research team hopes to have a vaccine available in September. Another is hoping their vaccine will be available by the start of 2021.
Because there are so many vaccine candidates of varying types, Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, told the Journal of the American Medical Association he's "cautiously optimistic" that there will be at least one that works against the novel coronavirus.
"The majority of people make an immune response which clears the virus. If the body is capable of producing an immune response, that's a pretty good proof of concept to say that you can get an immune response from a vaccine," Fauci said.
'We'll have a lot of vaccines'
But, he added, there's no guarantee. And Fauci said he's somewhat concerned about how long a vaccine might keep working. Natural immunity to coronaviruses that cause common colds often lasts less than a year, he noted.
Still, Fauci and other experts believe there will ultimately be several vaccines available to combat the novel coronavirus.
"I'm optimistic that we'll have a lot of vaccines," Dr Paul Offit told the Journal of the American Medical Association. He's director of the Vaccine Education Center at Children's Hospital of Philadelphia.
Vaccines will likely need to be given in two doses, he said. And, whether or not booster shots will be needed to ensure continued immunity against the virus remains to be seen.
The hurried pace of the research may leave some concerned about the safety of these vaccines.
Dr Kathryn Edwards, scientific director of the Vanderbilt Vaccine Research Program in Nashville and a fellow with the Infectious Diseases Society of America, said, "We're working very hard to generate a safe and effective vaccine. Every single vaccine that I recommend is one I would give my children and grandchildren. We may be going fast, but that doesn't mean we aren't being meticulous."
Vaccine testing a rigorous process
Edwards said there are systems in place, along with numerous checks and balances to ensure safety.
Vaccines generally go through lab and animal research, and then three phases of human trials, according to the US Centers for Disease Control and Prevention. Phase 1 trials are typically very small and look mostly for safety. Phase 2 trials are a bit larger and continue to evaluate safety and its effectiveness. Phase 3 trials are much larger, with a placebo group and at least one group receiving the vaccine to better measure how effective a vaccine is.
Here are some of the vaccines currently in human trials:
- Moderna. This two-dose vaccine is currently in a phase 2 trial with 600 participants, and is scheduled to move to a phase 3 trial with 30 000 participants in July. It's a type of vaccine called a messenger RNA vaccine. Essentially, it delivers a message to the body on how to make the antibody that can prevent the infection, according to Edwards. If the clinical trials go well, the company hopes to make the vaccine available by the end of 2020 or the start of 2021.
- University of Oxford/AstraZeneca. This vaccine – a modified virus that can trigger the production of antibodies – is currently in a phase 2 trial with 500 participants. A phase 3 trial with about 30 000 is planned to begin in early summer. Edwards said this vaccine is likely going to be given in a single dose.
- Pfizer/BioNTech. This partnership is currently testing four vaccines in phase 1 or 2 trials in Germany. Their vaccines are messenger RNA vaccines. Each trial will include about 200 people.
- Inovio. This company had already been working on a vaccine for MERS (another infection caused by a coronavirus), which allowed them to quickly switch to working on a vaccine for SARS-CoV-2 (the virus that causes Covid-19). Their vaccine is a DNA vaccine (a type of vaccine that contains the DNA coding specifically for making the antibodies against a particular virus), and phase 2 and 3 trials are expected to begin this summer in China and South Korea. Inovio believes it can have a million doses by the end of 2020.
There are also a number of other vaccines in upcoming or ongoing phase 1 trials, including vaccine candidates from Johnson & Johnson, Sanofi, Sinovac, CanSino Biologics and a collaboration between the Beijing Institute of Biological Products, the Wuhan Institute of Biological Products and the China National Pharmaceutical Group (Sinopharm).
So, if one or more of these vaccines works well and is safe, how can companies or governments quickly ramp up production?
Fauci explained that the government isn't waiting.
Millions of vaccine doses will be made before testing is complete
"We're going to start manufacturing doses of vaccine way before we even know that they work, so that by the beginning of 2021, we will have a couple of million doses," Fauci said. That way, if testing shows a vaccine works, an initial supply will already be available.
Offit noted that producing tens of millions of doses before it's known if a vaccine works isn't unprecedented – it was done with the polio vaccine.
He also urged caution. "There's a lot at stake here. If we rush it, if we put something out there into people's arms before we know what we need to know – or as much as we can reasonably know, then I think we could do harm," he said.
Still, Offit thinks if everyone pays attention to the science, there is "every reason to think that vaccines will be the heroes of this story".
What remains to be seen, however, is whether Americans will embrace a new vaccine.
The most recent poll, published on 2 June and conducted by the Washington Post-ABC News, found that roughly seven in 10 Americans would get a Covid-19 vaccine if immunisations were free and available to everyone.
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