Covid-19 news: lab experiments help explain why the virus is so deadly

The latest coronavirus news updated every day including coronavirus cases, the latest news, features and interviews from New Scientist and essential information about the covid-19 pandemic

Platelets could be to blame for deadly covid-19 blood clots

Tiny particles in the blood that promote clotting could be key to explaining why covid-19 can be deadly. The finding suggests that we may be able to use existing medicines to damp down platelet-triggered clotting in covid-19 patients.

People with severe covid-19 often have complications from excessive blood clotting, such as heart attacks, strokes and kidney damage. Tessa Barrett at NYU Langone Health in New York and colleagues found that platelets from 291 hospital patients with covid-19 had higher levels of two molecules involved in clotting compared with platelets from uninfected people. Levels were especially high in those who had to stay longer in hospital, found the study, published in Science Advances yesterday.

The team found that, when they grew healthy cells from blood vessel walls in a dish and exposed them to fluid from platelets that had encountered the pandemic coronavirus, they made more clotting molecules than when platelets were exposed to a coronavirus that causes the common cold. And the gaps between the cells became wider, which could be why blood vessels become more “leaky” in severe covid-19, causing fluid to build up in the lungs. “Our findings may explain in large part what makes covid-19 so much more deadly than its relatives that cause the common cold,” Barrett said in a statement.

Stroke drugs that block platelet-induced clotting are currently being trialled as a treatment for covid-19.

The UK is considering making covid-19 and flu jabs compulsory for frontline NHS staff and social care workers. The government has today launched a six-week consultation on making full vaccination against the two viruses a condition of employment, unless people are medically exempt. About nine in ten NHS staff have had two covid-19 doses so far, but that ranges from 78 to 94 per cent between hospitals. The flu vaccination rate among health service workers was 76 per cent last year.

Speculation continues on whether the UK will start offering third coronavirus vaccine doses to the wider population, with the i newspaper reporting today that a booster programme for older age groups could begin in the next two weeks. Yesterday the World Health Organization said there should be no general booster campaigns until at least the end of the year to let low-income countries give 40 per cent of their populations their first two doses. Here’s what we know so far about the pros and cons of boosting.

There is no evidence of airborne transmission of covid-19 in public toilets, according to a systematic review published in Science of Total Environment. The risk is very low, probably because people spend so little time in there and rarely interact with others, says Sotiris Vardoulakis at the Australian National University in Canberra.

UK researchers are looking for volunteers to help identify covid-19 infections from the sound of people’s speech and coughing. You need to be prepared to upload sound recordings of yourself within three days of taking a lateral flow or PCR test for covid-19