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 T cell responses to variants remain potent
Although worrying variants of the coronavirus identified in Brazil, South Africa and California have mutations that can help them resist treatment with antibodies and vaccines, the immune system’s T-cell responses to the variants are not affected in recovered patients and in people who received Moderna Inc or Pfizer Vaccines Inc / BioMTech SE, new data show. “We think it’s really good news,” said Alessandro Sette, of the La Jolla Institute for Immunology, whose team reported the findings on Monday at bioRxiv, before the peer review. Vaccine-induced T cells can recognize pieces of the virus’s peak protein, whereas T cells induced by previous infection recognize various parts of the virus, including the peak and other proteins, Sette said. “These parts are largely not altered / 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 are unlikely to prevent infection, they can reduce the severity of COVID-19, he added. T cell responses are known to be linked to the softer COVID-19, he noted, and may contribute to 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 risks of COVID-19
Asthma itself is not a more serious risk factor for hospitalization or COVID-19, and people whose asthma is triggered by allergies may actually be at a lower risk, according to new research presented at the company’s annual virtual meeting. American Academy of Allergy, Asthma and Immunology. 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 other medical conditions of patients who were associated with more serious COVID-19 diseases, including high blood pressure, heart disease, diabetes and obesity, “asthma was no longer a risk factor for hospitalization,” said Dr. Lauren Eggert. Among patients who were hospitalized, 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, said Eggert, is that in allergic asthma, the immune system “deregulates” or reduces the production of ACE2 proteins on the surface of cells, which are an important gateway to the coronavirus. (https://bit.ly/3reYR9j)
Antibodies to variants may offer cross-protection
Antibodies to a newer, more infectious coronavirus variant may prevent infection with earlier 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 prevalent, and in survivors of the second wave, when a new, more infectious and more difficult to treat variant predominated. First wave antibodies neutralized the first wave virus, but not the second wave virus. As expected, second-wave antibodies neutralized second-wave viruses. They also neutralized the first wave virus, although not as potently, according to an article published on Saturday in medRxiv before the peer review. At a news conference on Wednesday, co-author Alex Sigal of the Health Research Institute of Africa said the findings offer hope that vaccines based on the variant can 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, government adviser to COVID-19, predicted that by the end of 2021 most vaccine manufacturers will have adapted your 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 80 after a dose, Public Health England said on Monday, citing a study released in medRxiv before the review by pairs. The UK study also found that, in people over 70, two doses of the Pfizer vaccine are approximately 85% to 90% effective in preventing symptomatic diseases. Pfizer vaccine recipients in this age group who acquired 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 had been introduced recently, the researchers only had data after one dose. The effect against symptomatic diseases was approximately 60% to 75%, and there was also a protective effect against hospitalization, the researchers said. They noted that AstraZeneca data was collected while a more infectious variant was prevalent in the United Kingdom. Britain’s use of the AstraZeneca vaccine in the elderly contrasts with many European countries, which cited the lack of clinical trial data for their decision not to use it in the elderly. (https://bit.ly/3rktaLW; https://reut.rs/3kKIEX4)
Open https://tmsnrt.rs/3c7R3Bl in an external browser to see a Reuters graph on vaccines under development.
(Reporting by Nancy Lapid, Megan Brooks, Kate Kelland and Alexander Winning; Editing by Bill Berkrot)