Experiments with animals and human cell cultures found specialised antibodies in the blood of recovered COVID-19 patients that may “provide powerful protection” against the coronavirus that causes the disease.
If these results from Californian researchers are replicated in human clinical trials, these antibodies could be used as a treatment in the early, milder stages of the disease – but also as a short-acting vaccine.
All going well, the researchers say the antibodies – which were found to be “super potent” even in tiny amounts – could be deployed in clinical settings as early as January.
According to a statement from Scripps Research, a non-profit American medical research facility based in San Diego, “injections of such antibodies could be given to patients in the early stage of COVID-19 to reduce the level of virus and protect against severe disease”.
The antibodies also may be used “to provide temporary, vaccine-like protection against SARS-CoV-2 infection for healthcare workers, elderly people and others who respond poorly to traditional vaccines or are suspected of a recent exposure to the coronavirus”.
These bold claims are believed to work “in principle”.
How was the discovery made?
According to a statement from Scripps Research
- Blood samples were taken from patients who had recovered from COVID-19, across the continuum of mild to severe cases
- The researchers developed test cells that express ACE2, the receptor that SARS-CoV-2 hooks into, like a key into a lock. In this way the virus gains entry to infect our cells. See here
- In a set of initial experiments, the team tested whether antibody-containing blood from the patients could bind to the virus and strongly block it from infecting the test cells
- The scientists were able to isolate more than 1000 distinct antibody-producing B cells, each of which produced a distinct anti-SARS-CoV-2 antibody
- The team obtained the antibody gene sequences from these B cells so they could produce the antibodies in the laboratory
- By screening these antibodies individually, the team identified several that – even in tiny quantities – could block the virus in test cells, and one that could also protect hamsters against heavy viral exposure.
The researchers said this work – “including the development of the cell and animal infection models, and studies to discover where the antibodies of interest bind the virus” – was completed in less than seven weeks.
“The discovery of these very potent antibodies represents an extremely rapid response to a totally new pathogen,” said study co-senior author Dr Dennis Burton, the James and Jessie Minor Chair in Immunology in the Department of Immunology & Microbiology at Scripps Research.
It’s been done before
These “highly potent” antibodies can be mass-produced, using biotech methods, as a treatment that blocks severe disease and as a vaccine-like preventive that circulates in the blood for several weeks to protect against infection.
This approach already has been demonstrated successfully against Ebola virus and the pneumonia-causing respiratory syncytial virus, commonly known as RSV.
The researchers said that in the course of their attempts to isolate anti-SARS-CoV-2 antibodies from the COVID-19 patients, the researchers found one that can also neutralise SARS-CoV, the related coronavirus that caused the 2002-2004 outbreak of severe acute respiratory syndrome (SARS) in Asia.
The full study can be found here.
Other COVID-19 news
Reuters is reporting that scientists in Italy have found traces of the new coronavirus in wastewater collected from Milan and Turin in December 2019. This suggests that COVID-19 was already circulating in northern Italy before China reported the first cases.
CNN is reporting that indigenous people in Brazil are dying at almost twice the rate of the general population: 12.6 per cent compared to the disturbingly high national rate of 6.4 per cent. The report said that Paulinho Paiakan, an Amazon chief known for his environmental protests in Brazil, had died after being treated in hospital for coronavirus.
The New York Times reported on a new study that found antibodies may last only two to three months, especially in people who never showed symptoms while they were infected. The scientists said this didn’t necessarily mean that acquired immunity disappeared.