Japan suspended use of about 1.63 million doses of Moderna vaccine Thursday after contamination was found in unused vials, raising concern of a supply shortage as the country tries to accelerate vaccinations amid a COVID-19 surge.

The health ministry said contamination was reported from multiple vaccination sites. Some doses might have been administered, but no adverse health effects have been reported so far, officials said.

Japan was set to expand its coronavirus state of emergency for a second week in a row Wednesday, adding several more prefectures as a surge in infections fueled by the delta variant strains the country's health care system.

The government last week extended the state of emergency until Sept. 12 and expanded the areas covered to 13 prefectures from six including Tokyo. Sixteen other prefectures are currently under quasi-emergency status.

France's health watchdog on Tuesday recommended a third dose of the Covid-19 vaccine for people aged over 65 or considered at risk of developing serious forms of the disease.

The advice from the HAS watchdog was for people who had already received two vaccine doses, who will now be offered an mRNA vaccine such as the ones produced by Pfizer or Moderna, which France has ample supply of. 

What does full approval of Pfizer's COVID-19 vaccine mean?

It means Pfizer's shot for people 16 and older has now undergone the same rigorous testing and regulatory review as dozens of other long-established vaccines.

China reported no new domestic coronavirus cases Monday, and Beijing appears poised to bring to heel the pandemic's most serious resurgence in months -- driven by the highly contagious Delta variant -- with mass testing and targeted lockdowns.

The latest outbreak, which began in mid-July when cleaners at a Nanjing airport tested positive, is the most severe since Covid-19 first surfaced in the central city of Wuhan.

Israel said Monday it would offer Covid-19 vaccinations to students on school grounds as it announced the school year would open on time next week, despite surging coronavirus cases.

"Pupils... will be vaccinated on school grounds during school hours, subject to parental approval," a government statement said, confirming classes would begin on September 1.

Legal battles over masks in schools are being fought across the country, including in Arkansas, California, Florida, Kentucky, Michigan, Oklahoma, Nevada and Texas.

Rather than clarifying policy, these legal challenges have led to more confusion.

Israel has made third booster shots against COVID-19 available to people age 40 and older in an effort to fight a surge of the delta variant.

Prime Minister Naftali Bennett, who is 49, got his jab on Friday. He pledged to share "all the data, all the information, all the insights" of the effort. Israel has been a leader in the fight against the deadly coronavirus and last month became the first country to offer booster shots. The U.S. has approved, but not yet made available, boosters for older Americans as well.

Drug firm AstraZeneca on Friday announced positive results from a trial of a treatment for Covid-19 symptoms.

The drug, made from a combination of two antibodies, was initially developed as a treatment for those who had already been exposed to the disease.

U.S. health officials may soon recommend COVID-19 booster shots for fully vaccinated Americans. A look at what we know about boosters and how they could help fight the coronavirus:

WHY MIGHT WE NEED BOOSTERS?