Bill Gates explains what to know about COVID-19 vaccine development

Governor Charlie Baker released his plan for reopening Massachusetts, but life won't truly return to normal life until we have an effective COVID-19 vaccine. Moderna’s RNA vaccine is showing promise in its early trials. What does that mean and how far are we from a vaccine? What are the next steps? Bill Gates, whose foundation has pledged $250 million to COVID-19 response, answers these questions an more in a recent post on his Gates Notes blog. 

How long will it take to make a COVID-19 vaccine?

National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci believes that the vaccine will take eighteen months to create. In his article, Bill Gates notes that the time frame “could be as little as 9 months or as long as two years.” This is unprecedented, as the average vaccine takes five years to develop and includes three phases of trials:

  1. Phase one: A small group of healthy volunteers receive the preliminary formula. Different dosages are tested to find the safest and most effective dose.
  2. Phase two: After the formula is decided, hundreds of people of various ages and health statuses receive the vaccine for further testing.
  3. Phase three: Thousands of people receive the vaccine to see how it works in “natural disease conditions.” This phase takes the longest, because time is needed to see if the vaccine reduces how many people get sick.

Once the vaccine passes these phases, facilities are built to manufacture it and it’s submitted to various organizations such as WHO for approval.

This established process simply takes too long for the badly-needed COVID-19 vaccine. Developers are shortening the timeline by doing some steps simultaneously instead of sequentially. The New England Journal of Medicine outlines the modified process. 

Vaccine development timeline

Source: New England Journal of Medicine

Creating a vaccine is expensive, and keeping the steps sequential helps reduce financial risk. However, many governments and organizations are in full financial support of COVID-19 vaccine development, eliminating this problem and allowing several steps of the process to be done at once. For instance, governments and the private sector are already looking for facilities to manufacture the vaccine in to save time later in the development process.

In addition, there are many different vaccine candidates in production. As of April 9, 115 candidates were in development. “I think that eight to ten of those look particularly promising,” says Gates, but adds, “Our foundation is going to keep an eye on all the others to see if we missed any that have some positive characteristics, though.”

How will the vaccine be developed?

As mentioned, many, many vaccine candidates are currently in development. When it comes to vaccines, most are either “inactivated” vaccines (made with dead pathogens) or “live” (made with living but weakened pathogens). These methods are time tested. However, they're simply too slow for a COVID-19 because it takes time to grow the materials needed to produce the vaccine. 

Fortunately, there are two new approaches currently in the works: RNA and DNA vaccines. According to Scientific American, these gene-based vaccines work because they "use information from the genome of the virus to create a blueprint of select antigens...that hold genetic instructions. The researchers then inject the DNA or RNA into human cells. The cell’s machinery uses the instructions to make virus antigens that the immune system reacts to." This means that the vaccines take a lot less material to make, since the body is doing the work itself. Or as Gates puts it, “[y]ou essentially turn your body into its own vaccine manufacturing unit.” 

Gates and his foundation, the Coalition for Epidemic Preparedness Innovations (CEPI), have been developing an RNA vaccine platform for nearly ten years to combat diseases like malaria. However, there are no RNA vaccines currently in use, of which a COVID-19 vaccine could be the first. This poses a unique challenges for developers, who must prove that the vaccine provides immunity against coronavirus — and also prove that RNA is a viable platform. According to Gates, “It’s a bit like building your computer system and your first piece of software at the same time.”

The Moderna vaccine mentioned above, the first to start human trials, is an RNA vaccine. The company recently announced that the vaccine showed positive Phase I data, which suggests it generates a similar immune response to those who contracted and recovered from COVID-19. 

How effective will the vaccine be?

An ideal vaccine has 100% efficacy, but most current vaccines don't come close to this. Gates believes that 70% efficacy will be enough to stop the pandemic. 60% could potentially work, but localized outbreaks may still occur. Anything lower than that likely won’t create enough herd immunity to stop COVID-19.

One big challenge of developing the COVID-19 vaccine is making sure it’s effective for the elderly. Vaccines generally become less effective in older people because the aging process impacts the effectiveness of the immune system. This could be mitigated by making the COVID-19 vaccine stronger, or by requiring multiple doses. 

The vaccine has to work, but it has to be safe, too. A safe vaccine might cause mild side effects, but it won’t make people sick. Gates uses the smallpox vaccine, the only one to completely eliminate a disease, as an example. Although it was highly effective, it also caused scarring at the injection site and resulted in bad side effects for many people. "The smallpox vaccine was far from perfect, but it got the job done,” Gates says, “The COVID-19 vaccine might be similar.”

Even with the accelerated vaccine timeline, developers are still conducting robust safety trials and collecting real-world evidence. 

How will the vaccine be distributed?

The COVID-19 vaccine won’t do much good if it can’t be distributed throughout the world, something that’s never been done before. Right now, experts can’t even be sure where or in what kind of facility the vaccine will be manufactured. Transporting the vaccine may also be challenging, especially if it's an RNA vaccine. Most vaccines can be stored at 4°C, which is the average refrigerator temperature. But RNA vaccines would need to be stored at -80°C, making it much more difficult to transport to warmer parts of the world.

And it simply won’t be possible to give everyone in the world immediate access to the vaccine. Generally speaking, the country in which the vaccines are manufactured gets first access. It's not certain if this will happen with the COVID-19 vaccine. There's general agreement that health workers should get the vaccine first, but no one can decide who should be next. Gates believes that lower-income areas should be some of the first places to get the vaccine. “COVID-19 will spread much quicker in poor countries because measures like physical distancing are harder to enact,” he explains, “More people have poor underlying health that makes them more vulnerable to complications, and weak health systems will make it harder for them to receive the care they need. Getting the vaccine out in low-income countries could save millions of lives.”

What should we do while we wait for the vaccine?

Although there’s currently a lot of uncertainty surrounding the COVID-19 vaccine, Gates believes that we’re on the right track. In the meantime, he advises that everyone should to continue following local and national guidelines. “Our ability to get through this outbreak will depend on everyone doing their part to keep each other safe,” he says.

For more information on COVID-19 guidelines, check the CDC’s website.

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