Communities worldwide are emerging from lockdowns due to the SARS-CoV-2 pandemic virus, and it remains to be seen whether enough people will continue to wear masks, practice social-distancing, and take hygiene measures that are strong enough to stave off increases in infections. So far, the statistics in the United States are indicating that cases of the illness caused by the virus, COVID-19, will continue to increase.
Worldwide, over 400,000 people have died from COVID-19. Researchers have been searching for ways to reduce the death rate and find treatments for the infection. There is hope in dexamethasone, but it is only useful in severe cases and it does not work for every patient. A vaccine is also still a long way off.
A team of researchers is getting us closer to another treatment option - potent antibodies that have been found in the blood of people who recovered from COVID-19. These antibodies were found to protect cells growing in culture from the virus. The findings, which are paving the way to clinical trials that test these antibodies as preventive medications and treatments for active cases, have been reported in Science.
“The discovery of these very potent antibodies represents an extremely rapid response to a totally new pathogen,” said the study co-senior author Dennis Burton, Ph.D., the James and Jessie Minor Chair in Immunology in the Department of Immunology & Microbiology at Scripps Research.
It's possible that these antibodies could one day be administered to patients in the early phase of a COVID-19 infection so that severe disease is less likely, and virus levels are lowered. The antibodies could potentially be used as a kind of temporary vaccine, a prophylactic that could be given to those that may have been exposed, or who are at high risk, for example.
If antibodies that effectively neutralize the virus can be identified, it is likely that they could also be mass-produced and distributed for use once they're tested. This approach has helped in outbreaks of Ebola and respiratory syncytial virus.
“It has been a tremendous collaborative effort, and we’re now focused on making large quantities of these promising antibodies for clinical trials,” noted the study co-lead author Thomas Rogers, M.D., Ph.D., an adjunct assistant professor in the Department of Immunology & Microbiology at Scripps Research, and assistant professor of Medicine at UC San Diego. The research was quickly performed by teams at Scripps Research; IAVI, a nonprofit scientific research organization; and the University of California San Diego School of Medicine.
In this work, the researchers isolated antibodies from people that recovered from COVID-19 infections that ranged from mild to severe. They also created a test to determine whether cells that express a receptor that promotes viral infection, ACE2, were protected from infection by these antibodies. Over 1,000 antibody-producing cells were collected, and they were analyzed individually. Several blocked the virus in the cell culture model, and one was effective in a hamster model of heavy virus exposure.
“We leveraged our institution's decades of expertise in antibody isolation and quickly pivoted our focus to SARS-CoV-2 to identify these highly potent antibodies,” said study co-author Elise Landais, Ph.D., an IAVI principal scientist.
The researchers suggested that if safety tests go well, clinics may be able to try these antibodies in patients as soon as January.
“We intend to make them available to those who need them most, including people in low- and middle-income countries,” Landais added.
The research also happened to reveal an antibody that can protect against SARS, which caused a viral outbreak in 2002. “That discovery gives us hope that we will eventually find broadly neutralizing antibodies that provide at least partial protection against all or most SARS coronaviruses, which should be useful if another one jumps to humans,” Burton said.
Another study has suggested that antibodies against the SARS-CoV-2 virus tend to be short-lived - though that does not mean immunity is. More research will also be needed to understand how immunity against this virus will work in different people.