By Nancy Lapid
March 8 (Reuters) – The following is a summary 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.
Vaccine responses are weaker in the elderly
The COVID-19 vaccine from Pfizer Inc and the German partner BioNTech SE causes weaker immune responses in the elderly compared to younger and middle-aged adults. Researchers studied 91 vaccine recipients under the age of 60 and 85 recipients older than 80 years. Seventeen days after the second of two doses, almost one third (31%) of the elderly recipients had no antibodies that could neutralize the virus. This was true for only 2% of the younger group, the researchers reported on medRxiv on Friday before peer review. Even among those under the age of 60, only 16% neutralized antibodies after the first dose, the researchers found. “But that does not mean that the elderly should expect serious complications if they become infected,” said co-author Ortwin Adams of Düsseldorf University Hospital in Germany. “Recent reports from Israel, England and Scotland show that hospitalization and severe disease progression are significantly lower than those not vaccinated, even in people over 80 and even after the first vaccination against COVID-19,” Adams said. . “However, it may mean that the elderly need to be vaccinated sooner than young people to achieve long-term protection. The results also suggest that transmissions may still be possible in some elderly people after vaccination,” he said, adding that ‘measures’ to effectively broadcast occur, must be continued. “(https://bit.ly/3bpAsIG)
Merck antiviral drugs may help speed up viral clearance
An experimental antiviral drug developed by Merck & Co and Ridgeback Biotherapeutics may help reduce viral load in patients with early COVID-19, according to preliminary results from a clinical trial. Researchers presented their findings at the 2021 conference on retroviruses and opportunistic infections on Saturday, but did not publish a formal report. In the 202-patient study, people who were not symptomatic for more than 7 days and who were not hospitalized received the oral antiviral molnupravir or a placebo. In data from less than half of the trial participants, none of 47 patients who had molnupravir had positive viral cultures after five days of treatment, compared with 6 of 25 patients (24%) who took the placebo . Merck said the data on the safety and efficacy of the drug and the additional secondary objectives of the study will be presented at an upcoming medical meeting. (https://reut.rs/3kXjfJR)
Immune memory enhances vaccine response of COVID-19 survivors
New data gives an idea why some COVID-19 survivors require only one dose of the two doses of Pfizer / BioNTech and Moderna Inc vaccines. Researchers have detected the reaction of the vaccine in 11 survivors of mild COVID-19 and 33 individuals who were never infected. In all, the vaccines caused the immune system to produce antibodies along with so-called B cells that remember the virus and are ready to produce new antibodies to fight it, although the extent of the B cell response was lower in older people. Those not previously infected had ‘benefited from both doses’, with additional antibodies and the increase in memory B cells after the second survey, researchers reported on medRxiv on Saturday before peer review. However, COVID-19 survivors had significant responses to the first dose, with no increase in antibodies or memory B cells after the second dose. Survivors ‘memory B cells before vaccination correlated strongly with their antibody levels after vaccination, suggesting that these B cells were the likely source of survivors’ antibody levels after just one shot, says co-author John Wherry of University of Pennsylvania. This suggests that memory B cells will play important roles as antibody levels decline over time, he added. Because memory B cells can be the source of new antibodies with some “adaptability,” they may play a role in immunity to various viruses, he speculated. (https://bit.ly/3qtVv0M)
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(Reporting by Nancy Lapid; Edited by Bill Berkrot)