Coronavirus briefs
New recorded infections in India have tumbled from nearly 100,000 a day in September to under 10,000. In England a study found that infections have fallen by two-thirds since early January. California reported fewer than 5,000 new daily cases for the first time since November. The world’s first “human challenge” study of covid-19 got the go-ahead in Britain. Volunteers aged 18-30 will be exposed to the coronavirus to establish how much of it is needed to cause infection. The hours needed to shut and disinfect New York’s subway system at night have been reduced from four to two, a sign, said an official, that the city “is starting to return to normalcy”. North Korea reportedly tried to hack Pfizer’s computers to find details of its vaccine. Strange for a country that officially claims…