By Nancy Lapid
March 8 (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.
Vaccine responses appear weaker in the elderly
The COVID-19 vaccine from Pfizer Inc and German partner BioNTech SE induces weaker immune responses in older people compared to younger, middle-aged adults, new data suggest. The researchers studied 91 recipients of the vaccine under the age of 60 and 85 recipients over the age of 80. Seventeen days after the second of the two doses, almost a third (31%) of the elderly recipients did not have antibodies capable of neutralizing the virus. This was true for only 2% of the younger group, the researchers reported on Friday in medRxiv before the peer review. Even among those under the age of 60, only 16% had neutralizing antibodies after the first dose, the researchers found. “But that does not mean that the elderly should expect serious complications if they are infected,” said co-author Ortwin Adams of the University Hospital in Dusseldorf, Germany. “Recent reports from Israel, England and Scotland show that rates of hospitalization and serious disease progression are significantly lower than in unvaccinated ones, even in people over 80 and even after the first vaccination with COVID-19”, said Adams. “However, it could mean that older people need to be revaccinated earlier than young people to generate lasting protection. The results also suggest that transmissions may still be possible in some of the elderly after vaccination,” he said, adding that “measures to effectively prevent transmissions it must be continued. “(https://bit.ly/3bpAsIG)
Merck’s antiviral drug can help accelerate viral elimination
An experimental antiviral drug being developed by Merck & Co and Ridgeback Biotherapeutics may help reduce viral loads in patients with early COVID-19, according to preliminary results from a clinical trial. The researchers presented their findings on Saturday at the 2021 Retrovirus and Opportunistic Infections Conference, but did not publish a formal report. In the study of 202 patients, people who were symptomatic for no longer than 7 days and who were not hospitalized received either the oral antiviral molnupravir or a placebo. In data from less than half of trial participants, after five days of treatment, none of the 47 patients who took molnupravir had positive viral cultures, compared with 6 out of 25 patients (24%) who took the placebo. Merck said data on the drug’s safety and efficacy and the study’s additional secondary objectives will be presented at an upcoming medical meeting. (https://reut.rs/3kXjfJR)
Immune memory increases the vaccine response of COVID-19 survivors
New data provides a clue as to why some survivors of COVID-19 may need only one dose of the two-dose Pfizer / BioNTech and Moderna Inc vaccines. The researchers tracked responses to the vaccine in 11 survivors of mild COVID-19 and 33 never-infected individuals. In all, vaccines induced the immune system to produce antibodies along with so-called B cells, which remember the virus and remain ready to produce new antibodies to fight it, although the magnitude of the B cell response is less in older people. . Those not previously infected “benefited from both doses”, with an increase in additional antibodies and memory B cells after the second injection, the researchers reported on Saturday at medRxiv before the peer review. Survivors of COVID-19, however, had significant responses to the first dose without increasing antibodies or memory B cells after the second dose. Survivors ‘memory B cell levels before vaccination correlated strongly with their post-vaccination antibody levels, “indicating that these B cells were the likely source” of survivors’ increased antibody levels after just a single injection, he said. co-author John Wherry of the University of Pennsylvania. . This suggests that memory B cells will play important roles if antibody levels drop over time, he added. Because memory B cells may be the source of new antibodies with some degree of “adaptability”, they may play a role in immunity to variant viruses, he speculated. (https://bit.ly/3qtVv0M)
Open https://tmsnrt.rs/3c7R3Bl in an external browser to get a graph of Reuters about vaccines under development.
(Reporting by Nancy Lapid; Editing by Bill Berkrot)