WASHINGTON (AFP) - The US Department of Veterans Affairs (VA) said Monday (July 26) its more than 100,000 health care personnel would have to get Covid-19 shots, becoming the first federal agency to institute a mandate as California and New York City announced new vaccine requirements affecting workers.

President Joe Biden's administration had previously been reluctant to support such measures, but is now confronted with a Delta variant-driven surge that is sweeping mainly through America's tens of millions of unvaccinated.

"Whenever a Veteran or VA employee sets foot in a VA facility, they deserve to know that we have done everything in our power to protect them from Covid-19," said VA Secretary Denis McDonough in a news release.

"With this mandate, we can once again make - and keep - that fundamental promise." The statement added that four unvaccinated VA employees had died in recent weeks, all of whom were unvaccinated.

Personnel such as physicians, dentists, podiatrists, optometrists, registered nurses and others now have eight weeks to be fully vaccinated.

Earlier this month, VA officials said more than 70 per cent of the agency's 300,000 employees were fully vaccinated. The new order applies to 115,000 people, according to the Military Times.

The move came as part of a broader shift, with New York City announcing municipal workers will need to get vaccinated or submit to weekly tests, and California ordering a similar measure for its government employees but also extending the rule to private sector health workers.

New York's order will affect more than 300,000 city personnel, including police, firefighters and teachers, and will go into effect September 13, Mayor Bill de Blasio said Monday.

California's directive will apply to almost 240,000 state workers and hundreds of thousands more private sector health workers, with full compliance required by August 21, according to a news release by Governor Gavin Newsom's office.

San Francisco Mayor London Breed meanwhile said anyone hired by the city or county would need a vaccine before they can begin their job, extending the scope of a mandate on existing city workers announced last week.

Delta surge

The United States is in the midst of a surge driven by Delta, the most contagious coronavirus variant identified to date, which now accounts for more than 89 per cent of US cases, according to estimates.

Some 52,000 people are being infected every day, according to the Covid Act Now tracker.

Hotspots include the states of Arkansas, Florida - which accounts for almost a quarter of all new cases - Louisiana and Missouri.

They have all lagged behind the national vaccination rate, but White House coronavirus coordinator Jeff Zients told reporters last week that these states were recently registering higher immunisation rates in light of the summer surge.

Just over 49 per cent of the total US population has been fully vaccinated, well below the 85 to 90 per cent experts now estimate is required for population immunity.

"We're at about 67 per cent (with prior infections counted) So we need a lot more vaccinations," Ashish Jha, Dean of Brown University School of Public Health, tweeted about immunity on Sunday.

Controversy is meanwhile building over mandates.

On Monday, 57 medical groups representing millions of doctors, nurses, pharmacists and other health workers called for mandatory vaccinations for all health staff.

A recent WebMD report of 2,500 hospitals showed that about one in four health care workers have not been vaccinated - primarily nursing aides, emergency medical technicians and nurses.

While Democratic-led jurisdictions are implementing vaccine requirements, several Republican-led states have instead passed laws banning such measures, particularly in schools.

But with the vast majority of Covid hospitalisations and deaths occurring among the unvaccinated, and the ranks of the unvaccinated skewing politically conservative, there are now signs Republican lawmakers are coming around.

"These vaccines are saving lives," Florida Governor Ron DeSantis said at a news conference last week.

And on Thursday number two House Republican Steve Scalise joined the chamber's GOP Doctors Caucus, a group of 18 lawmakers who are licensed medical experts, to tell Americans to "get the vaccine."