COVID SCIENCE-Highly effective vaccine, new warning signs, disrupted heart rhythm

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.

Pfizer vaccine appears highly effective An experimental COVID-19 vaccine from Pfizer Inc and BioNTech SA appears to be more than 90% effective, based on data analyzed midway through a gold-standard clinical trial, the companies announced on Monday. The trial has enrolled 43,538 participants so far, including many from racially and ethnically diverse backgrounds. Pfizer said researchers had analyzed 94 confirmed cases of COVID-19 in trial participants and found the vast majority of the infections were in volunteers in the placebo group. The trial is expected to continue until 164 confirmed cases of COVID-19 are available for analysis. BioNTech's co-founder and chief executive said he was optimistic that the protective effect of the experimental COVID-19 vaccine would last for at least a year. (https://reut.rs/3p80uoJ; https://reut.rs/36pRJxM; https://bit.ly/36i8lr8)

New study adds to COVID-19 symptom list Fever, coughing, and shortness of breath are known symptoms of COVID-19, but other warning signs can include weakness, poor blood sugar control and gastrointestinal complaints, according to a new study published on Saturday in the American Journal of Emergency Medicine. Researchers analyzed nearly 12,000 visits by adult patients to emergency departments at five New York City hospitals. They found COVID-19 in 57.5% of patients who went to the hospital because of weakness, falls, or altered mental status, in 55.5% of those who came in because their blood sugar was out of control, and in 51.4% of patients whose chief complaint was a gastrointestinal problem. Patients over the age of 65 tended to have more atypical complaints such as diarrhea, fatigue and weakness. Patients with dehydration, altered mental status, falls and high blood sugar were at higher risk for death in the study. The new findings can help hospitals provide better care and are "also important for family members and people that work with the elderly to better identify possible warning signs of COVID-19 infection," coauthor Dr. Christopher Clifford of the Icahn School of Medicine at Mount Sinai told Reuters. (https://bit.ly/3pcqjnp)

COVID-19 can fuse heart cells, disrupt rhythm COVID-19 can disrupt the heart's electric system, according to a report undergoing peer review at a Nature Research journal. The heart pumps blood by sending electrical signals through its "conducting cells" to tell "muscle cells" to contract. Normally, each conducting cell activates the one next to it in a domino effect to ensure smooth contractions. An autopsy of a COVID-19 patient found the virus had infected her heart in an unusual patchy pattern, "with small islands of infected cells here and there," Dr. Jay Schneider of the Mayo Clinic in Rochester, Minnesota told Reuters. Upon further study in the laboratory, his team realized the spike protein on the surface of the new coronavirus can create holes between neighboring cells, causing them to fuse together. So instead of orderly electrical signal transmission and a steady heart rhythm, the signals flow like "a tsunami tidal wave" through the fused cells.