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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, the disease caused by the virus.
Immune system T cell responses to variants remain powerful
While the disturbing coronavirus variants identified in Brazil, South Africa and California have mutations that could help them resist antibody treatments and vaccines, the immune system’s T cell responses to the variants are unaffected in recovered patients and in people who have received Moderna Inc or Pfizer. Inc / BioMTech SE vaccines, new data shows. “We think this is really good news,” said Alessandro Sette of the La Jolla Institute for Immunology, whose team reported the results Monday on bioRxiv ahead of the peer review. T cells induced by vaccines can recognize chunks of the virus spike protein, while T cells induced by a previous infection recognize multiple parts of the virus, including the spike and other proteins, Sette said. “These parts are largely unmodified / mutated into the variants,” he explained. “This means that T cell responses recognize both ‘ancestral’ sequence and variants.” While circulating memory T cells probably don’t prevent infection, they could reduce the severity of COVID-19, he added. T-cell responses are known to be linked 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 the risk of COVID-19
Asthma on its own is not a more serious risk factor for hospitalization or COVID-19, and people with asthma triggered by allergies may actually be at low risk, new research shows presented at the American Academy of Allergy, Asthma and Immunology Virtual Annual Meeting. Researchers at Stanford University studied 5,596 patients who tested positive for COVID-19 from March to September 2020. Of these, 11% were hospitalized, including 100 patients with asthma. After taking into account the other medical conditions of patients that have been linked to more severe COVID-19 disease, including high blood pressure, heart disease, diabetes and obesity, “the asthma was no longer a risk factor for hospitalization, ”said Dr. Lauren Eggert. Among hospitalized patients, asthma was not significantly associated with the severity of the disease, she said. The researchers also found that patients with allergic asthma were almost half as likely as patients with other types of asthma to require hospitalization. One possible explanation, Eggert said, is that in allergic asthma, the immune system “down-regulates”, or reduces production, of ACE2 proteins on cell surfaces that are a major entry point for the coronavirus. (https://bit.ly/3reYR9j)
Antibodies against variants may offer cross-protection
Antibodies to a newer, more infectious variant of the coronavirus could prevent infection with earlier variants, lab studies suggest. In test-tube experiments, researchers studied the neutralizing effects of antibodies obtained from people infected with COVID-19 during 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 contagious and more difficult to treat variant has 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 virus in the first wave, but not as effectively, according to an article published on medRxiv on Saturday ahead of the peer review. At a press conference on Wednesday, co-author Alex Sigal of the Africa Health Research Institute said the findings offer hope that vaccines based on the variant could protect against this variant and others circulating in 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 adjusted their vaccines accordingly. (https://bit.ly/3rhXJSq; https://reut.rs/2MHJaZ8)
UK finds vaccines protect older people
Pfizer and AstraZeneca vaccines are over 80% effective in preventing COVID-19 hospitalizations in people over 80 after a dose, Public Health England said on Monday, citing a study published on medRxiv ahead of the review by pairs. The British 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 illnesses. Pfizer vaccine recipients in this age group who developed symptomatic infections had a 44% lower risk of hospitalization and a 51% lower risk of death compared to unvaccinated patients. Since the two-dose AstraZeneca vaccine was only recently introduced, researchers only had data after a single dose. The effect against symptomatic disease was around 60% to 75%, and there was also a protective effect against hospitalization, the researchers said. They noted that AstraZeneca data was collected when a more infectious variant was predominant in the UK. Britain’s use of the AstraZeneca vaccine on the elderly contrasts with many European countries, which cited a lack of clinical trial data to justify their decision not to use it on the elderly. (https://bit.ly/3rktaLW; https://reut.rs/3kKIEX4)
Open https://tmsnrt.rs/3c7R3Bl in an external browser for a Reuters graphic on vaccines in development.
(Reporting by Nancy Lapid, Megan Brooks, Kate Kelland and Alexander Winning; Editing by Bill Berkrot)
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