In the race to create a vaccine for the novel coronavirus, some researchers are testing new approaches they hope can ultimately produce vaccines in months rather than years, Eileen Drage O'Reilly and I write.
Why it matters: The global COVID-19 outbreak is a harsh reminder of the urgent need to be able to vaccinate large swaths of the population fast — in this pandemic and the next.
What's happening: The world is pinning its hopes on a vaccine for COVID-19 to save lives, return to normal, and emerge from an economic recession.
- Experts estimate it could take at least 12–18 months for a vaccine to be widely available, with glimmers of hope for some limited availability sooner tempered by a reality that vaccines typically take multiple years to develop.
State of play: There are at least 92 vaccines under development for COVID-19 (see below).
- 22 of those are experimental DNA- or RNA-based vaccines, which provide the most hope for speedy development.
- "These technologies will be pushed to limits they’ve never been pushed to before, and we’ll see how they perform," Harvard Medical School's Dan Barouch says of DNA and RNA vaccines. "We’ll know a lot more about the status of these technologies at the end of COVID-19."
Background: For more than 200 years, vaccines have worked by introducing the body to either a version of the virus itself that doesn't cause disease, or an antigen that's typically a protein on the virus surface. Both prime the immune system and spur it into action should someone encounter the virus.
- Those approaches gave the world effective vaccines for polio, measles, hepatitis B and other diseases.
- But each time, researchers have to develop anew the biological machinery — cells and reactor conditions — needed to manufacture the vaccines.
- This simply takes too much time during a crisis, says Johns Hopkins Center for Health Security's Amesh Adalja.
What's new: DNA and RNA vaccines are a potential avenue for speeding up vaccine development.
- Instead of delivering the antigen, these vaccines introduce the DNA or RNA sequence that encodes the antigen, and it is produced by the body's cells. (RNA acts as an information-carrying intermediary between DNA and the protein it encodes.)
- When a new virus emerges, the idea is an antigen from it could be quickly sequenced and the genetic code plugged into an already-approved vaccine platform with an existing tried-and-true manufacturing process. That would eliminate the long process of developing a line of cells for producing the vaccine.
But, but, but: No RNA and DNA vaccines have been approved for humans — for any virus.
- DNA vaccines, which have been in development for two decades, sometimes struggle to cause a strong immune response to a virus.
- RNA vaccines are a newer approach, and delivering them to the right cells can be a challenge.
Several teams are working on RNA vaccines for SARS-CoV-2, the virus that causes COVID-19, including biotech company Moderna and the NIH's Vaccine Research Center. Their RNA vaccine is in Phase I trials at three sites, testing the safety of doses and its ability to induce an immune response.
- "If it works, it is a good technology to respond quickly. It has not been shown to work in terms of protection and to be mass produced, " Barouch says. "It doesn’t mean they can’t be; they just haven’t yet."
Meanwhile, Barouch and his collaborators at Johnson & Johnson are taking a different approach, using a non-infectious version of an adenovirus — a common cold virus — to shuttle DNA for an antigen into the body's cells.
The big picture: Testing vaccines quickly and not relying on cells to manufacture them would be a game changer for future pandemics.
- Moving vaccine production out of cells could be one component for decentralized, local production of medicine, vaccines and diagnostics for responding to pandemics and addressing antibiotic-resistant microbes, says Northwestern University's Mike Jewett, a biochemical engineer who is developing systems for manufacturing vaccines and drugs without cells.
The bottom line: This pandemic is a testbed for the next generation of vaccine technologies.