Many are wondering if the race for a vaccine will bear fruit as early as January 2021.
Here is why you can be optimistic about the delivery of a COVID-19 vaccine.
Human immune system cures COVID-19. In as many as 99% of all COVID-19 cases, the patient recovers from the infection, and the virus is cleared from the body.
Some of those who have had COVID-19 may have low levels of virus in the body for up to three months after infection. But in most cases these individuals can no longer transmit the virus to other people 10 days after first becoming sick.
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.
Vaccines in clinical trials have been shown to raise anti-spike antibodies that block virus infection in cells in the lab.
At least seven companies have developed monoclonal antibodies, laboratory-manufactured antibodies that recognize the spike protein. These antibodies are entering clinical trials.
Spike glycoprotein contains multiple targets. The spike protein has many locations where antibodies can bind to and neutralize the virus. That’s good news because with so many vulnerable spots, it will be difficult for the virus to mutate to avoid a vaccine.
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.
One side effect seen in the past was antibody-dependent enhancement of infection. This occurs when antibodies don’t neutralize the virus but instead allow it to enter into cells via a receptor intended for antibodies. Researchers have found that by immunizing with the spike protein, high levels of neutralizing antibodies can be produced. This lessens the risk of enhancement.
A second potential problem posed by some vaccines is an allergic reaction that causes inflammation in the lung. However, researchers have now learned how to design vaccines to avoid this allergic response.
The U.S. government is supporting the development of several different vaccines via Operation Warp Speed. The goal is to deliver 300 million doses of a safe and effective vaccine by January 2021.
The U.S. government is committing $8 billion to seven different COVID-19 vaccines.
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.
Phase III clinical trials are underway. During a phase III trial, the final step in vaccine development, 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.
Three vaccines began phase III trials in July. Other COVID-19 vaccines will be starting phase III within weeks.
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.
Once a vaccine is proven safe in phase III trials, a stockpile of it will already exist.
Vaccine distributors are being contracted now. McKesson Corp. has already been contracted by the Centers for Disease Control and Prevention to distribute a COVID-19 vaccine to sites where the vaccine will be administered. Dr. William Petri is a professor of medicine at the University of Virginia. Distributed by The Associated Press.
