The record of 11,978 cases diagnosed on Tuesday marks the most new infections reported in a single day since the start of the pandemic.

The previous record was set on September 2 with 11,345 new infections logged during the Delta variant's wave.

Omicron, first detected in South Africa, is apparently more contagious but causes less cases of severe illness and death -- especially among vaccinated people.

In Israel as elsewhere, the variant is spreading so fast -- straining testing, schools, hospitals and airlines -- that some experts are urging a focus instead on hospital admissions.

Those, as well as deaths from coronavirus, aren't climbing as quickly -- the result, experts say, of protections offered by vaccinations.

The rapid climb in infections has pushed Israeli leaders far from the clear protocol of vaccinations, testing, quarantining and contact tracing that characterised the government's response early in the pandemic. The country's speedy vaccination early on made Israel a world leader.

Now, Israel is believed to be the first country to offer a fourth vaccination to people 60 and older, as well as those with compromised immune systems.

Prime Minister Naftali Bennett on Tuesday said early results from a study at Sheba Medical Centre showed a nearly five-fold increase in antibodies among people with a fourth jab.

Israel is rapidly changing rules and practices to adapt, including scaling back quarantines to keep the economy from shutting down.

Australian Associated Press