By Nancy Lapid
(Reuters) – The following is a summary of some of the latest scientific studies on the new coronavirus and efforts to find treatments and vaccines for COVID-19, the disease caused by the virus.
No variant has escaped all types of antibodies, so far
The human immune system produces many antibodies in response to infection or vaccination with COVID-19, and no variant of the new coronavirus can escape them all, according to a study published on Thursday in bioRxiv before the peer review. The researchers looked at how mutations in the coronavirus variants affect the ability of antibodies to reach a key region at the peak of the virus called the receptor-binding domain (RBD), which has been rapidly mutating. In particular, the researchers studied three sets of antibodies that were classified by the structural characteristics that affect their binding to the virus. Despite the diversity of antibodies, only one class dominates the antibody response that targets RBD, they found. They also looked at how many different classes of antibodies can be prevented by new variants of the coronavirus. “Several strains have mutations that reduce binding by two classes of antibodies, but so far no strains have mutations that escape all three classes,” said co-author Jesse Bloom of the Fred Hutchinson Cancer Research Center in Seattle. “We suggest that it is important to keep an eye out while the virus continues to evolve.” (https://bit.ly/3luUNzA)
Coronavirus variants can infect mice
Some of the new variants of the coronavirus can cause COVID-19 in mice, the researchers found. The implications, such as whether mice can transmit the virus to humans, will require further studies, they said. The original virus strain identified in Wuhan, China, could not produce disease in mice because the spikes on its surface could not bind well to the ACE2 receptor protein in the animals’ cells. Some of the new worrying variants – particularly the first ones identified in South Africa and Brazil – have mutations that overcome this challenge, giving them the ability to infect and make mice sick, the researchers reported on Thursday in bioRxiv before the review by pairs. “This is really great news for animal studies to better understand infection and disease, as mice are widely available … to study many pathologies and easier to work with than larger animals, such as hamsters or ferrets” , said co-author Etienne Simon-Loriere of the Institut Pasteur in Paris. Whether mice can transmit the virus to each other or to humans has yet to be determined. “We have no experience in assessing the health risk posed by this newly acquired SARS-CoV-2 capability, but this is definitely something that will need to be done,” said Simon-Loriere. “Nobody wants the virus to move to a new reservoir from which it could return to humans, as was feared on mink farms, and I hope that doesn’t happen.” (https://bit.ly/3cSCj86)
Boston homeless patients benefit from the recovery unit
Homeless people needed to be hospitalized for COVID-19 less often after the Boston Medical Center created a recovery unit for them, according to a new report. Boston experienced an increase in the number of cases during the spring of 2020, which disproportionately affected homeless people and threatened to overwhelm the hospital’s capacity. In response, the COVID-19 Recovery Unit was installed near the Boston Medical Center to provide isolation and quarantine space for homeless people who did not need hospitalization and were clinically stable, saving hospital beds for patients with severe COVID-19. When the unit was open for two months, the hospital saw a 28% reduction in admissions for COVID-19 patients who were homeless, the researchers reported in the JAMA Network Open. COVID-19’s social detachment and quarantine restrictions “were developed from the perspective of the ‘rich’ and not the ‘poor’,” said co-author Dr. Joshua Barocas of the Boston University School of Medicine. “By refocusing the conversation about homeless people, we can really see that resources are needed to keep them and all of us safer.” (https://bit.ly/3cOjEdR)
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(Reporting by Nancy Lapid; Additional reporting by Carolyn Crist in Athens, Georgia; Editing by Bill Berkrot)