The response of COVID SCIENCE-T cells to virus variants remains strong; Asthma does not increase the serious risk of COVID-19


By Nancy Lapid

March 3 (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.

Immune system T-cell responses to variants remain potent

While the worrisome variants of the coronavirus identified in Brazil, South Africa, and California have mutations that could help them resist antibody treatments and vaccines, immune system T-cell responses to the variants are unaffected in recovered patients and in people who have received Moderna Inc or Pfizer. Inc / BioMTech SE, show new data. “We think this is really good news,” said Alessandro Sette of the La Jolla Institute of Immunology, whose team reported the findings Monday in bioRxiv ahead of peer review. Vaccine-induced T cells can recognize parts of the virus spike protein, while T cells induced by previous infection recognize multiple parts of the virus, including the spike and other proteins, Sette said. “These pieces are largely unchanged / mutated in the variants,” he explained. “This means that T cell responses recognize the ‘ancestral’ sequence and variants equally well.” While circulating memory T cells likely won’t prevent infection, they could reduce the severity of COVID-19, he added. T-cell responses are known to be related to milder COVID-19, he noted, and may help limit the severity of COVID-19 induced by variants that partially or largely escape neutralizing antibodies. (https://bit.ly/384IAMo)

Asthma Does Not Increase COVID-19 Risks

Asthma itself is not a more severe risk factor for hospitalization or COVID-19, and people whose asthma is triggered by allergies may actually be at lower risk, according to new research presented at the virtual annual meeting of the American Academy. of Allergy, Asthma and Immunology. Researchers from Stanford University studied 5,596 patients who tested positive for COVID-19 between March and September 2020. Of these, 11% were hospitalized, including 100 patients with asthma. After taking into account the other medical conditions of the patients that have been linked to the more serious COVID-19 disease, including high blood pressure, heart disease, diabetes and obesity, “asthma was no longer a factor in risk of hospitalization, “said Dr. Lauren Eggert. Among the patients who were hospitalized, asthma was not significantly associated with the severity of the disease, he said. The researchers also found that patients with allergic asthma were nearly half as likely as patients with other types of asthma to need hospitalization. One possible explanation, Eggert said, is that in allergic asthma, the immune system “down-regulates” or reduces the production of ACE2 proteins on cell surfaces that are an important port of entry for the coronavirus. (https://bit.ly/3reYR9j)

Antibodies against variants may offer cross protection

Antibodies against a newer and more infectious variant of the coronavirus could prevent infection by older variants, laboratory studies suggest. In test-tube experiments, researchers studied the neutralizing effects of antibodies obtained from people infected with COVID-19 in the first wave of the pandemic in South Africa, when the initial version of the virus was predominant, and in survivors of the second wave, when a new, more infectious and more difficult to treat variant predominated. The first wave antibodies neutralized the first wave virus but not the second wave virus. As expected, the second wave antibodies neutralized the second wave viruses. They also neutralized the first wave virus, though not as powerfully, according to a medRxiv article posted Saturday ahead of peer review. At a press conference Wednesday, co-author Alex Sigal of the Africa Health Research Institute said the findings offer hope that vaccines based on the variant may protect against this and other variants circulating around the world. Pfizer, AstraZeneca Plc, Johnson & Johnson and Moderna are already developing vaccines based on the variant identified in South Africa. Salim Abdool Karim, a senior government adviser on COVID-19, predicted that by the end of 2021 most vaccine manufacturers will have adapted their vaccines accordingly. (https://bit.ly/3rhXJSq; https://reut.rs/2MHJaZ8)

UK finds vaccines protect the elderly

The Pfizer and AstraZeneca vaccines are more than 80% effective in preventing COVID-19 hospitalizations in people over the age of 80 after a dose, Public Health England said Monday, citing a study published in medRxiv before peer review. The UK study also found that in people over the age of 70, two doses of the Pfizer vaccine are about 85% to 90% effective in preventing symptomatic disease. Pfizer vaccine recipients in that age group who acquired symptomatic infections had a 44% lower risk of hospitalization and a 51% lower risk of death compared to unvaccinated patients. Because the two-dose AstraZeneca vaccine was recently introduced, the researchers only had data after one dose. The effect against symptomatic disease was about 60% to 75%, and there was also a protective effect against hospitalization, the researchers said. They noted that the AstraZeneca data was collected while a more infectious variant was predominant in the UK. The British use of the AstraZeneca vaccine in older people stands in contrast to many European countries, which have cited a lack of clinical trial data for their decision not to use it in older people. (https://bit.ly/3rktaLW; https://reut.rs/3kKIEX4)

Open https://tmsnrt.rs/3c7R3Bl in an external browser to see a Reuters graphic on vaccines in development.

(Reporting by Nancy Lapid, Megan Brooks, Kate Kelland, and Alexander Winning; Edited by Bill Berkrot)

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