As fall approaches rapidly, many are wondering if the race for a vaccine will bear fruit as early as January 2021.
I am a physician-scientist and infectious diseases specialist at the University of Virginia, where I care for patients and conduct research into COVID-19. I am occasionally asked how I can be sure that researchers will develop a successful vaccine to prevent COVID-19. After all, we still don’t have one for HIV, the virus that causes AIDS.
Here is where the current research stands, where I think we will be in five months and why you can be optimistic about the delivery of a COVID-19 vaccine.
It should therefore be much easier to make a vaccine for the new coronavirus than for infections such as HIV where the immune system fails to cure it naturally. SARS-CoV-2 doesn’t mutate the way that HIV does, making it a much easier target for the immune system to subdue or for a vaccine to control.
2. Antibodies targeting spike protein prevent infection
A vaccine will protect, in part, by inducing the production of antibodies against the spike protein on the surface of SARS-CoV-2, the virus that causes COVID-19.
The virus needs the spike protein to attach to and enter human cells to reproduce. Researchers have shown that antibodies, like those made by the human immune system, bind to the spike protein, neutralize it and prevent the coronavirus from infecting cells in laboratory culture.
At least seven companies have developed monoclonal antibodies, laboratory-manufactured antibodies that recognize the spike protein. These antibodies are entering clinical trials to test their ability to prevent infection in those who are exposed, for example, through a household contact.
Monoclonal antibodies may also be effective for treatment. During an infection, a dose of these monoclonal antibodies could neutralize virus, giving the immune system a chance to catch up and manufacture its own antibodies to combat the pathogen.
Multiple parts of the spike would need to mutate to evade neutralizing anti-spike antibodies. Too many mutations to the spike protein would change its structure and render it incapable of binding to ACE2, which is key to infecting human cells.
4. We know how to make a safe vaccine
Safety of a new COVID-19 vaccine is improved by researchers’ understanding of potential vaccine side effects and how to avoid them.
By supporting multiple COVID-19 vaccines, the government is hedging its bets. Only one of these vaccines needs to prove safe and effective in clinical trials for a COVID-19 vaccine to be made available to Americans in 2021.
6. Vaccines passing through phase I and II trials
Phase I and phase II trials test if a vaccine is safe and induces an immune response. Already the results to date from three different vaccine trials are promising, triggering the production of anti-spike neutralizing antibodies levels that are two- to four-fold higher than those seen in people who have recovered from COVID-19.
During a phase III trial, the final step in vaccine development process, the vaccine is tested on tens of thousands of individuals to determine if it works to prevent infection with SARS-CoV-2, and that it is safe.
Operation Warp Speed is paying for the production of millions of doses of vaccines and supporting vaccine manufacturing at an industrial scale even before researchers have demonstrated vaccine efficacy and safety.
The advantage of this strategy is that once a vaccine is proven safe in phase III trials, a stockpile of it will already exist and it can be distributed immediately without compromising full assessment of safety and efficacy.
I believe that it is realistic that we will know sometime in late 2020 whether some COVID-19 vaccines are safe, exactly how effective they are and which ones should be used to vaccinate the U.S. population in 2021.