San Francisco: The following is a roundup of some of the latest scientific studies on the novel coronavirus and efforts to find treatments and vaccines for COVID-19, the illness caused by the virus.
COVID-19 antibodies last at least three months
People infected with COVID-19 develop antibodies targeting the new coronavirus that last for at least three months, according to two reports published in Science Immunology.
The two studies, together involving nearly 750 patients, both point to immunoglobulin G (IgG) antibodies, which start showing up well after an infection begins, as the longest-lasting. Researchers found IgG antibodies with two targets – a spike protein on the virus that helps it infect cells, and a part of the spike called the receptor binding domain (RBD) – lasted more than 100 days. While the protective effect of COVID-19 antibodies is not completely clear, Jen Gommerman of the University of Toronto, coauthor of the study, said her team also found levels of so-called neutralizing antibodies, which inactivate the virus, “appeared to be very stable.”
The other study, from Harvard Medical School, reported similar findings. This means that a properly designed vaccine “should elicit a durable antibody response that has the potential to neutralize the virus,” Gommerman said. Her group also found that antibodies in saliva correlated with antibodies in blood, but at this point the saliva tests are not sensitive enough to replace blood tests.
COVID-19 symptoms linger for months for many
Three months after becoming ill, many COVID-19 patients still have symptoms, two studies confirm, and the more severe the initial infections, the higher the odds of persistent problems. In Spain, doctors checked back with 108 patients, including 44 who had been severely ill. At 12 weeks after diagnosis, 76% still reported after-effects, with 40% reporting three or more coronavirus-related health issues, doctors said in a paper posted on Thursday on medRxiv ahead of peer review. The most common complaints were shortness of breath, physical weakness, cough, chest pain, palpitations, and psychological and cognitive disorders. In a similar study of 233 U.S. COVID-19 patients – eight of whom had been severely ill – one in four still had symptoms 90 days after first feeling ill. Rates were higher for patients who had been sicker: 59.4% at 30 days and 40.6% at 90 days. “But even for very mild and initially asymptomatic cases, 14.3% have complications persist for 30 days or longer,” the authors reported on Sunday on medRxiv. In the U.S. study, the most common persistent symptoms were impaired smell and taste, difficulty concentrating, shortness of breath, memory loss, confusion, headache, heart palpitations, chest pain, pain with deep breaths, dizziness, and rapid heartbeat.–Agencies
