USA coronavirus update: California tops 15,000 deaths; infection rate falls

California's death count from the coronavirus has surpassed 15,000 even as the state sees widespread improvement in infection levels.

A tally by Johns Hopkins University put California's death toll at 15,027 on Sunday, the fourth-highest in the country. New York has suffered by far the most deaths -- 33,087 -- followed by New Jersey, which has about half as many. Texas is third.

California has had the most confirmed virus cases in the country with about 775,000, but key indicators have fallen dramatically since a spike that started after Memorial Day weekend prompted statewide shutdowns of businesses.

The state's infection rate has fallen to 3 per cent in the last week, the lowest level since the first days of the pandemic.

Hospitalisations have dropped below 2,700, the lowest since early April, and the number of patients in the intensive care unit has dropped below 850.

With figures falling, California last month instituted a new four-tier system for counties to reopen more businesses and activities.

Most counties remain in the most restrictive level but some could move to a lower level when the state updates the ratings on Tuesday.