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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.
Variant in Brazil more prone to reinfecting survivors
A variant of the coronavirus circulating in Brazil is likely to re-infect people who survived infections with earlier versions of the coronavirus, new data suggests.
The variant that emerged in Brazil, called P.1, carries a mutation that is already known to make a variant prevalent in South Africa more difficult to treat with antibodies and more difficult to prevent with available vaccines.
The new data suggest that in many recovered patients, immunity to older versions of the virus will not provide immunity to P.1.
The researchers tested the neutralizing ability of the antibodies in plasma samples taken from survivors of COVID-19 caused by earlier versions of the virus.
The plasma “had 6 times less neutralizing capacity” against the P.1 variant than it did against earlier versions of the virus, the researchers reported Monday before peer review on a preprint server belonging to The Lancet.
“The lower neutralizing capacity of SARS-CoV-2 antibodies and the partial immunity against new variants suggests that reinfection could occur in convalescent or even vaccinated individuals,” the authors said.
In a separate document published Wednesday on medRxiv ahead of peer review, some of the same researchers estimated that among every 100 survivors of COVID-19 due to older versions of the virus, 25 to 60 could be re-infected if exposed to it. the P.1 variant because their antibodies could not protect them.
As of Thursday, according to the US Centers for Disease Control and Prevention, there have been 13 cases of COVID-19 due to P.1 in the United States.
COVID-19 Vaccine Antibodies Pass Into Breast Milk
COVID-19 antibodies induced by Pfizer Inc / BioNTech and Moderna Inc vaccines can pass into breast milk, a small study suggests, although it is not yet clear how long the antibodies will be present.
Six nursing mothers who planned to receive both doses of the Pfizer / BioNTech or Moderna vaccines provided researchers with milk samples before and after vaccination, with the last sample taken two weeks after the second injection.
None of the women had been infected with the coronavirus.
One week after the first injection, all of the women had COVID-19 antibodies in their breast milk.
Antibody levels dropped slightly afterward and then rose dramatically after the second shot.
The two vaccines were equally effective at inducing the antibodies, although antibody levels varied from woman to woman, the research team reported Tuesday on medRxiv ahead of peer review.
“More research is needed on the longevity of the antibody response in breast milk, as well as the magnitude and duration of the effect on infant immunity to the virus,” the researchers said. – Reuters
