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By Nancy Lapid
(Reuters) – The following is a summary of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19.
1.5 million children have lost their parents to COVID-19 so far
In the first 14 months of the pandemic, an estimated 1.5 million children worldwide suffered the death of a parent, custodial grandparent or other caring parent , because of COVID-19, according to a study published in The Lancet https: //bit.ly/3wW1wqg on Tuesday. Estimates of the number of orphans are taken from mortality data from 21 countries that account for 77% of COVID-19 deaths globally and from the United Nations Population Division. “For every two COVID-19 deaths worldwide, one child is left behind in the face of the death of a parent or caregiver,” Dr Susan Hillis of the Centers’ COVID-19 response team for Disease Control and Prevention of the United States, which led the study, said in a statement. The number of COVID-19 orphans will increase as the pandemic progresses, she added. There is an urgent need to put these children first and “support them for many years into the future,” Hillis said. Study co-author Lucie Cluver, University of Oxford, said: “And we have to react quickly because every 12 seconds a child loses their guardian to COVID-19.”
Potential brain gateway found for coronavirus
Researchers have found a potential route of entry for the coronavirus into the human brain that may help explain the effects of COVID-19 on the brain and nervous system that plagued many patients. To date, there is no evidence that the virus directly infects neurons – brain cells that receive and send messages to and from the body. In a new study, experimenting with a mass of artificially cultured cells created to resemble the brain, researchers found that neurons appeared “impermeable” to coronavirus, said Joseph Gleeson of the University of California, San Diego. But cells called pericytes, which wrap around blood vessels and carry the surface protein that the virus uses to enter, turned out to be a different story. When the researchers added pericytes to their artificial brains and then added the virus, “we found an incredibly robust infection,” not only pericytes but also neurons, Gleeson said. They report in Nature Medicine https://go.nature.com/3eHmumt that the pericytes served as “factories” for the virus, from which it could multiply. The main targets were astrocytes, which play a crucial role in regulating electrical impulses in the brain, supplying nutrients to neurons, and maintaining the “blood-brain barrier” that protects the brain from foreign substances. The results, Gleeson said, suggest that “the pericytes could serve as an entry point for SARS-CoV-2”, which could either lead to local increases in the virus or to inflammation of the blood vessels which can cause an stroke.
Vaccine boosters not yet needed, researchers say
Two doses of an mRNA vaccine from Pfizer / BioNTech or Moderna are effective in neutralizing the highly contagious Delta variant of the coronavirus which is or will soon be dominant in most places, suggesting that immediate booster doses are unlikely to be needed. the researchers said. They did not measure the ability of vaccines to protect against infection in the real world. In their lab experiments using blood samples from vaccinated volunteers, however, the Delta mutations caused only small reductions in the proportion of antibodies that could neutralize the virus, they said. Mutations in the less prevalent beta and gamma variants reduced the neutralizing ability of antibodies more significantly, but not to the point where vaccinees would appear unprotected, the researchers reported Sunday in an article published on medRxiv https: // bit.ly/3iB4HhV before peer review. Vaccine boosters may be needed in the future to help overcome some variants, Yale University co-author Akiko Iwasaki said in a tweet on Tuesday. His team also found that overall, levels of neutralizing antibodies after vaccination were higher in COVID-19 survivors than in uninfected vaccine recipients. “This is not surprising,” Iwasaki told Reuters, “because the infection itself induces immune responses, which were enhanced by the two doses of the vaccine.”
Click for a Reuters graphic https://tmsnrt.rs/3c7R3Bl on vaccines in development.
(Reporting by Nancy Lapid; Editing by Bill Berkrot)
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