FACTBOX-Latest on the worldwide spread of the coronavirus

* Arsenal have cancelled their pre-season tour to the United States after a small number of positive COVID-19 cases at the club, the team said. ASIA-PACIFIC * Australia's two largest states reported sharp increases in new COVID-19 cases on Wednesday, a blow to hopes that lockdown restrictions would be lifted with more than half the country's population under stay-at-home orders. * South Korea reported a daily record of 1,784 coronavirus cases for Tuesday, breaking a mark set last week, as the authorities struggled to get on top of a surge in outbreaks linked to the Delta variant.

Britain's COVID-19 cases rose by nearly 41% over the past week, while the chief of the Tokyo 2020 organizing committee did not rule out canceling the Olympics if infections are spiked, as more athletes tested positive and sponsor ditched plans to attend Friday's opening ceremony. DEATHS AND INFECTIONS

* Eikon users, see COVID-19: MacroVitals https://apac1.apps.cp.thomsonreuters.com/cms/?navid=1592404098 for a case tracker and summary of news EUROPE

* London's High Court ruled that Britain acted lawfully over its so-called traffic lights system for travelers entering Britain in a case brought by Manchester Airports Group, backed by several airlines. * Arsenal have canceled their pre-season tour to the United States after a small number of positive COVID-19 cases at the club, the team said.

ASIA-PACIFIC * Australia's two largest states reported sharp increases in new COVID-19 cases on Wednesday, a blow to hopes that lockdown restrictions would be lifted with more than half the country's population under stay-at-home orders.

* South Korea reported a daily record of 1,784 coronavirus cases for Tuesday, breaking a mark set last week, as the authorities struggled to get on top of a surge in outbreaks linked to the Delta variant. * The pandemic-postponed Tokyo 2020 Olympics began on Wednesday with Japanese women's softball pitcher Yukiko Ueno getting Games competition underway in what the head of the World Health Organization said was needed as "a celebration of hope".

* Myanmar politician Nyan Win, a senior adviser to ousted leader Aung San Suu Kyi, died in hospital on Tuesday after becoming infected with COVID-19 in jail, his party said, as the Southeast Asian country struggles with an exponential rise in infections. * China reported 22 new COVID-19 cases in the mainland on July 20 versus 65 a day earlier, the country's health authority said.

* India reported its highest death toll in a month on Wednesday - at nearly 4,000 - after its richest state reconciled its death count with 3,509 previously unreported fatalities, the health ministry said. AMERICAS

* The Delta variant is the cause of more than 80% of new U.S. cases, but the authorized vaccines remain more than 90% effective in preventing hospitalizations and deaths, said top U.S. infectious disease expert Anthony Fauci in a Senate hearing. * The U.S. State Department has lowered its COVID 19-related travel advisory for India to "Level 3 – Reconsider Travel," the department said in a statement.

* A fully vaccinated White House official tested positive off-site, White House press secretary Jen Psaki said. Psaki also said she is in regular contact with the conservative news network Fox News about its coverage of the vaccine. MIDDLE EAST AND AFRICA

* Iran imposed a one-week lockdown in the capital and a nearby province as daily caseloads hit a record high, state television reported. MEDICAL DEVELOPMENTS

* Europe's drug regulator said it had started a real-time review of the vaccine developed by French drugmaker Sanofi and Britain's GlaxoSmithKline, the fifth shot currently under such a review. * Scientists are working on a benchmark for COVID-19 vaccine efficacy that would allow drugmakers to conduct smaller, speedier human trials to get them to market and address a huge global vaccine shortage.

ECONOMIC IMPACT * Asian shares stumbled on Wednesday, while the dollar was firm as investors worried that a fast-spreading coronavirus variant could impede a global economic recovery.

* U.S. homebuilding increased more than expected in June, but permits for future home construction fell to an eight-month low, likely reflecting hesitancy caused by expensive building materials as well as shortages of labor and land.