What you need to know about the coronavirus right now
Delhi locks down
India's capital region of Delhi ordered a six-day lockdown on Monday as daily Covid-19 cases nationwide hit a new record and the health system crumbled under the weight of new infections.
India's hospitals are struggling with a shortage of beds, oxygen and key medicines as infections pass the 15 million mark, second only to the United States.
"Delhi's health system is unable to take more patients in big numbers," Chief Minister Arvind Kejriwal told a virtual press briefing on Monday.
Thai infections ease after days of record highs
Thailand reported 1,390 new cases on Monday, slowing slightly after a run of record daily highs, amid a new wave of infections that has seen a third of the country's cases recorded this month alone.
The new infections were down by a fifth from Sunday's record 1,767, which the coronavirus taskforce said was due to measures to control the spread and requests for people to avoid travel and gatherings.
"Measures we have introduced for next two weeks will reduce cases, travel and risky activities," Apisamai Srirangsan, a spokeswoman for the taskforce, told a briefing.
Australia-New Zealand 'travel bubble' begins
Hundreds of passengers from Australia began arriving in New Zealand airports on Monday after authorities reopened borders, a pandemic milestone that allows quarantine-free travel between the countries for the first time in over a year.
Though most Australian states have allowed quarantine-free visits from New Zealand residents since late last year, New Zealand had enforced isolation for arrivals from its neighbour, citing concerns about sporadic virus outbreaks there.
Television footage showed emotional scenes at the airports with families reuniting and scores of passengers thronging Australia’s international departure terminals.
South African variant may 'break through' Pfizer vaccine
The coronavirus variant discovered in South Africa can break through the protection provided by Pfizer and BioNTech's Covid-19 vaccine to some extent, a real-world data study in Israel found. However, the variant's prevalence in Israel is very low and the vaccine remains highly effective.
The study has not been peer reviewed. It compared almost 400 people who had tested positive for Covid-19, after they received one or two doses of the vaccine, against the same number of unvaccinated patients with the disease.
It matched age and gender, among other characteristics.
New trial studies if people can catch virus again
British scientists on Monday launched a trial which will deliberately expose participants who have already had Covid-19 to the coronavirus again to examine immune responses and see if people get reinfected.
In February, Britain became the first country in the world to give the go-ahead for so-called "challenge trials" in humans, in which volunteers are deliberately exposed to Covid-19 to advance research into the disease caused by the coronavirus.
The study launched on Monday differs from the one announced in February as it seeks to reinfect people who have previously had Covid-19 in an effort to deepen understanding about immunity, rather than infecting people for the first time.