Pfizer Stock – Vaccines appear effective vs New York virus variant; super-spreader events drive variants
(Reuters) – The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.
New York variant does not escape vaccines
Antibodies induced by the Pfizer/BioNTech and Moderna vaccines and the antibody therapy from Regeneron Pharmaceuticals all are able to neutralize a coronavirus variant on the rise in New York, lab experiments show. The New York variant contains mutations – E484K, S477N and D235G – that experts feared might reduce antibody efficacy. The new results “show that this potential problem is not going to be a problem,” said Nathaniel Landau of New York University, who coauthored a report posted Wednesday on bioRxiv ahead of peer review. The mutations all cause changes to the spike protein the virus uses to infect cells and are located in the part of the spike protein where antibodies bind. The researchers exposed replicas of the New York variant to blood from recipients of either the vaccines or the Regeneron antibody combination used to treat infected patients. Antibodies induced by the vaccines were “very effective at binding to the altered spike protein,” Landau said. The Regeneron therapy also was “still a potent blocker” of the virus. “The vaccines are very effective at stopping this highly contagious variant strain of SARS COV2 which is why it is more important than ever to get vaccinated,” Landau said. (bit.ly/3ssmR9u)
Super-spreader events give life to virus variants
Super-spreader events, in which an infected person transmits the virus to many other people, are critical to the survival and predominance of new variants, researchers have found. If coronavirus transmission only occurs one person at a time, a new variant is unlikely to gain a foothold and will usually die out in the population by chance, said Daniel Reeves of Fred Hutchinson Cancer Research Center in Seattle. “Even very strong variants can die out if they are ‘unlucky’ and don’t happen by chance to be transmitted in a super-spread event,” he added. His team’s new mathematical models, posted on Wednesday on medRxiv ahead of peer review, show that early super-spreader events infecting more than five people are critical to a variant’s survival, while super-spreader events infecting more than 20 people are critical to its eventual predominance. Even a very infectious new variant usually needs a super-spreader event to help it overtake a current variant, Reeves explained. The findings provide yet another reason to focus on preventing large super-spreader events by prohibiting large indoor gatherings, focusing on adequate ventilation indoors, and mandating highest quality masks (K95 or N95) when group exposures are unavoidable, the researchers concluded. (bit.ly/39fZ4C7)
Coronavirus can infect mouth tissues, spreading infection
The new coronavirus can infect salivary glands, which can then play a role in transmitting the virus to the lungs or digestive tract via saliva, according to a report published on Thursday in Nature Medicine. Researchers first studied mouth cells from healthy volunteers, looking for two proteins the coronavirus uses as entryways. Cells in the salivary glands and the gums expressed both proteins, making them vulnerable to infection. Next, researchers discovered genetic material from the virus in mouth tissues from COVID-19 patients, indicating infection. They also found evidence that the virus was replicating in some of these cells. Among 27 volunteers with mild COVID-19, those with virus in their saliva were more likely to report loss of taste and smell, suggesting that infected salivary glands might help explain some oral symptoms of COVID-19, the researchers said. “The study’s findings suggest that the mouth, via infected oral cells, plays a bigger role in SARS-CoV-2 infection than previously thought,” study coauthor Kevin Byrd of the University of North Carolina at Chapel Hill said in a statement. “When infected saliva is swallowed or tiny particles of it are inhaled, we think it can potentially transmit SARS-CoV-2″ further into the body.” (go.nature.com/3spbFdQ)
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Reporting by Nancy Lapid; Editing by Bill Berkrot