By Sharon Bernstein
SACRAMENTO, Calif. (Reuters) - A California community that has been a bellwether of the coronavirus pandemic's rampage across the United States warned on Thursday that the number of cases of more contagious COVID-19 variants is increasing to worrisome levels.
"The region's progress in curbing the pandemic remains precarious," the health department in Santa Clara County, home to California's Silicon Valley, said.
"County residents are therefore urged to avoid travel, quarantine if travelling, and consistently use face coverings."
The situation in Santa Clara, which was home to an early surge of coronavirus in California last year and the nation's first death from COVID-19, offers a window into the pandemic's progress across the wider United States.
Several states, including Florida and Michigan, are struggling to contain a resurgence of the virus linked to new highly contagious variants.
The 7-day daily average of cases across the United States has been increasing continuously since March 19, Reuters analysis shows. Over the past 13 days, the average daily number of new cases of COVID-19 has increased by about 17%, from 5,5591 on March 19 to 6,4814 on March 31. Total cases stand at 30,562,884, including 552,932 deaths.
"We're already seeing surges in other parts of the country, likely driven by variants," Santa Clara Health Officer Sara Cody said in a statement. "Combined with the data we are seeing locally, these are important warning signs that we must continue to minimize the spread."
The rise in cases comes despite unprecedented efforts to vaccinate people worldwide and across the United States, where nearly 30% of the population had received at least one vaccine dose by Thursday, according to data from the U.S. Centers for Disease Control and Prevention (CDC).
Many U.S. states are moving to ease pandemic public health restrictions, and people who have been vaccinated are starting to venture out from a year of staying mostly at home.
But with the vast majority of the population still unvaccinated, experts warn that could be a recipe for a deadly fourth wave of the disease.
In California, the most populous U.S. state with 40 million residents, about 5.6 million people, or 17.3% percent of the population, had received one vaccine dose, the CDC said.
As cases have leveled off in recent weeks, state officials have reopened activities like restaurant dining and are making plans to send children back to school.
However, California Governor Gavin Newsom warned that with at least seven variants of the virus in circulation, the state is not close to achieving so-called herd immunity, which would require the vast majority of people to be inoculated.
"Now is not the time to spike the ball," said Newsom, who received his own vaccination on Thursday in Los Angeles. "Now is not the time to announce, "mission accomplished."
In neighbouring Canada, officials in the province of Ontario declared a limited lockdown beginning on Saturday, while French president Emmanuel Macron on Wednesday ordered his country into its third national lockdown.