COVID-19 survivors may have long lasting immunity: Study
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Final data from Pfizer vaccine trial shows 95% efficacy
Final results from Pfizer Inc’s pivotal COVID-19 vaccine trial show it had a 95% success rate – even higher than an earlier analysis – and two months of follow-up data without serious side effects, the company said on Wednesday. In the study involving about 43,000 volunteers, 162 of the 170 who contracted COVID-19 had received a placebo, not the vaccine. Of the 10 participants who had severe COVID-19, only one had received the vaccine. The final analysis of the trial’s data comes a week after interim results showed the vaccine was more than 90% effective. Moderna Inc on Monday released preliminary data for its vaccine, showing 94.5% effectiveness. Pfizer said the efficacy its two-dose vaccine, developed with German partner BioNTech SE, was consistent across different age and ethnic groups. Efficacy in adults over age 65 was over 94%. Pfizer said it expects to make up to 50 million vaccine doses this year – enough to inoculate 25 million people – and up to 1.3 billion doses in 2021.
Respiratory muscle damage linked to severe COVID-19
Critically ill COVID-19 patients develop virus-induced damage of respiratory muscles, scientists at Amsterdam UMC in The Netherlands reported on Monday in JAMA Internal Medicine. They performed autopsy studies of the diaphragm, the main respiratory muscle, in 26 COVID-19 patients who died in the intensive care unit (ICU) and 8 ICU patients who died without COVID-19. In everyone, the diaphragm muscle cell membranes contained a protein called ACE2, which the new coronavirus uses as an entryway into cells. The researchers found genetic evidence of the virus in diaphragm muscle cells in some of those who died from COVID-19, and microscopy analyzes showed much more connective tissue scarring (fibrosis) in COVID-19 patients’ diaphragms, indicating damage, study coauthor Coen Ottenheijm told Reuters. He said the diaphragm damage may help explain why it is often difficult for COVID-19 patients to breathe on their own again after they have been on mechanical ventilators in the ICU. It may also explain the persistent shortness of breath in patients recovering from COVID-19.