Jan 4 (Reuters) - Here's what you need to know about the...

Jan 4 (Reuters) - Here's what you need to know about the coronavirus right now:

Delhi chief minister tests positive for COVID-19 India reported 37,379 new COVID-19 cases in the past 24 hours, the health ministry said on Tuesday, the most since early September as the Omicron coronavirus variant overtakes Delta in places such as the capital, New Delhi.

One of the newly infected people was Delhi Chief Minister Arvind Kejriwal, who spoke at an election rally on Monday without wearing a mask. Similar rallies have been held across states voting in the next few months in assembly elections. Kejriwal said in a Twitter post he had isolated at home and urged those who came in touch with him in recent days to do similar and be tested for COVID-19.

Australia COVID-19 cases surge Australia's COVID-19 cases touched a new high on Tuesday amid an Omicron surge in its two most populous states as hospitalisations in New South Wales state, home to Sydney, surpassed record numbers seen during the Delta outbreak.

Australia is also battling a shortage of rapid antigen tests, delays with PCR results and the closure of a number of testing sites, with pathology laboratories swamped by a backlog of tests. Prime Minister Scott Morrison ruled out the government covering the cost of people testing themselves for COVID-19. "The problem at the moment is that the lack of (rapid antigen tests) is completely hampering personal responsibility and it is a frustration that is a glaring hole in the current management of COVID," Chris Moy, vice president of the Australian Medical Association, told ABC Radio.

Coronavirus leaves survivors with self-attacking antibodies Months after recovering from SARS-CoV-2 infection, survivors have elevated levels of antibodies that can mistakenly attack their own organs and tissues, even if they had not been severely ill, according to new findings. Among 177 healthcare workers who had recovered from confirmed coronavirus infections contracted before the availability of vaccines, all had persistent autoantibodies, including ones that can cause chronic inflammation and injury of the joints, skin and nervous system.

Susan Cheng of the Cedars-Sinai Smidt Heart Institute in Los Angeles and her team are investigating whether autoantibody elevations are linked with persistent symptoms in people with long COVID and planning to study autoantibody levels after infections with newer variants of the virus.

U.S. schools delay openings as Omicron rages Thousands of U.S. schools delayed this week's scheduled return to classrooms following the holiday break or switched to remote learning as the Omicron variant of the coronavirus pushed COVID-19 cases to record levels.

In other school districts, officials pressed on with plans to reopen, including in hard-hit New York City, where one out of every three COVID-19 tests over the last week was positive for the virus, according to city data released on Monday. Nationwide, an average of 18% of tests coming back positive, according to the Mayo Clinic.

Israel to start reopening to foreigners Israel said on Monday it will admit foreigners with presumed COVID-19 immunity from countries deemed medium-risk next week, partially reversing a ban imposed in late November in response to the fast-spreading Omicron variant. The Health Ministry said that, as of Jan. 9, foreign travellers from 199 "orange" countries will be admitted if they can prove they are vaccinated or have recovered from COVID-19.

The announcement came even as Prime Minister Naftali Bennett predicted that new cases could increase tenfold within days. The rapid pace of infection has led to many Israelis waiting hours in lines for COVID-19 tests, although Omicron has not brought corresponding rises in mortality.