As autumn arrives quickly, many are wondering whether the race for a vaccine will bear fruit as early as January 2021.
I am a physician-scientist and specialist in infectious diseases at the University of Virginia, where I care for and examine patients for COVID-19.
I am sometimes asked how I can be sure that researchers will develop a successful vaccine to prevent COVID-19. After all, we do not yet have one for HIV, the virus that causes AIDS.
Here’s where the current research stands, where I think we’ll be in five months and why you can be optimistic about delivering a COVID-19 vaccine.
Human Human System Cured COVID-19
In as many as 99 percent of all COVID-19 cases, the patient recovers from the infection, and the virus is eliminated from the body.
Some of those who have had COVID-19 may have low levels of virus in their 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 they first became ill.
It should therefore be much easier to get a vaccine for the new coronavirus than for infections such as HIV, where the immune system naturally does not cure it. SARS-CoV-2 does not mutate the way HIV does, making it a much easier target for the immune system to suppress than for a vaccine to control.
2. Antibodies that target spike protein prevent infection
A vaccine will, in part, protect 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 hook up and enter human cells to reproduce. Researchers have shown that antibodies, such as those produced by the human immune system, bind to the spike protein, neutralize it and prevent it from infecting coronavirus cells in laboratory culture.
Vaccines in clinical trials have been shown to increase anti-spike antibodies that block virus infection in cells in the lab.
At least seven companies have developed monoclonal antibodies, laboratory-produced antibodies that recognize the spike protein. These antibodies undergo clinical trials to test their ability to prevent infection in those who are exposed, for example through a domestic 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 pick up and produce its own antibodies to fight the pathogen.
3. Spike glycoprotein contains multiple targets
The spike protein has many locations where antibodies can bind to the virus and neutralize it. This is good news, because with so many vulnerable spots it will be difficult for the virus to mutate to prevent a vaccine.
Multiple parts of the spike would need to mutate to elicit neutralizing anti-spike antibodies. Too many mutations for the spike protein would alter the structure and make it impossible to bind to ACE2, which is the key to infecting human cells.
4. We know how to make a safe vaccine
Safety of a new COVID-19 vaccine is enhanced by researchers’ understanding of possible side effects of vaccines and how they can be prevented.
One side effect that has been seen in the past was anti-anti-infection improvement. This happens when antibodies do not neutralize the virus, but instead allow it to enter cells through a receptor intended for antibodies.
Researchers have found that by immunizing with the spike protein high levels of neutralizing antibodies can be produced. This reduces the risk of improvement.
A second potential problem posed by some vaccines is an allergic reaction that causes inflammation in the lungs, as seen in individuals vaccinated with a respiratory syncytial virus in the 1960s.
This is dangerous because inflammation in the lungs of the lungs makes it difficult to breathe. However, researchers have now learned how to design vaccines to prevent this allergic reaction.
5. Several different faxes in development
The US government is supporting the development of several different fax machines through Operation Warp Speed.
The goal of Operation Warp Speed is to deliver 300 million doses of a safe and effective vaccine by January 2021.
The U.S. government is making a major investment, allocating US $ 8 billion to seven different COVID-19 faxes.
By supporting multiple COVID-19 faxes, the government is hedging its bets. Only one of these vaccines should prove safe and effective in clinical trials for a COVID-19 vaccine that will be made available to Americans in 2021.
6. Faxes passing through Phase I and II trials
Phase I and Phase II tests test whether a vaccine is safe and induces an immune response. Though the results so far of three different vaccine studies are promising, triggering the production of anti-spike-neutralizing antibody levels that are two to four times higher than those seen in people who have recovered from COVID 19.
Moderna, Oxford, and Chinese company CanSino have all demonstrated the safety of their vaccines in Phase I and Phase II studies.
Phase III clinical trials are underway
During a Phase III trial, the final step in the 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.
The vaccine produced by Moderna and NIH and the Oxford-AstraZeneca vaccine began phase III trials in July. Other COVID-19 faxes will begin Phase III within weeks.
8. Acceleration of production and deployment of vaccines
Operation Warp Speed pays for the production of millions of doses of vaccines and supports fax production on an industrial scale even before researchers have proven that vaccines are effective and safe.
The advantage of this strategy is that once a vaccine has been proven safe in phase III studies, a stock of it will already exist and it can be distributed immediately without compromising the full assessment of safety and effectiveness.
This is a more cautious approach than that of Russia, which vaccinates the public with a vaccine before it has been shown to be safe and effective in Phase III.
9. Fax distributors are now contracted
McKesson Corp., the largest vaccine distributor in the US, has already been contracted by the CDC to distribute a COVID-19 vaccine to sites – including clinics and hospitals – where the vaccine will be administered.
I believe it is realistic that sometime in late 2020 we will know if some COVID-19 vaccines are safe, just how effective they are and what should be used to vaccinate the American population in 2021.
William Petri, Professor of Medicine, University of Virginia.
This article was republished from The Conversation under a Creative Commons license. Read the original article.
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