LOS ANGELES (CNS) — Providing further evidence of increased spread of COVID-19, Los Angeles County's daily number of new infections soared past the 1,100 mark Friday, doubling the number from just a week ago and the highest figure reported in a single day since March. 

The county Department of Public Health reported 1,107 new COVID cases on Friday, compared to 549 reported last Friday. The daily number of new infections has been rising steadily for at least two weeks, with officials blaming the rapid spread of the highly infectious "Delta" variant of the COVID virus.

The "Delta" variant is considered responsible for mass infections in India and outbreaks in the United Kingdom and beyond. Federal officials have said the variant is also believed to be responsible for a majority of new infections being reported in the United States — the vast majority of them among unvaccinated residents.

The number of people hospitalized in Los Angeles County due to the virus is also rising steadily, reaching 336 on Friday, according to state figures. That's up from 320 on Thursday. There were 83 people in intensive care as of Friday, up from 79 the previous day.

Friday's total of 1,107 new cases lifted the cumulative number of infections in the county throughout the pandemic to 1,255,434. The daily number is the highest reported by the county since early March.

"There are slightly under 4 million residents in L.A. County that are not yet vaccinated against COVID-19, and the risk of increased spread remains high among communities with lower vaccination rates," county Public Health Director Barbara Ferrer said in a statement. "This is particularly true if there are gatherings with unvaccinated friends and family in indoor settings. The need for masking and infection control among those not yet vaccinated remains important. This Delta variant of the COVID-19 virus spreads more easily than others. With vaccinations and good prevention measures, almost all of this transmission can be prevented."

Speaking to reporters Thursday, Ferrer said COVID-19 "has become a vaccine-preventable disease, so the first line of defense for everybody 12 and over is to build your confidence in this vaccine, get good information and come in as soon as possible to get vaccinated."

Echoing federal officials, Ferrer again stressed that vaccinated residents have strong protection against COVID-19 — including the "Delta" variant. Of nearly 4.7 million fully vaccinated residents in Los Angeles County, there have been only 2,822 people who have subsequently tested positive for the virus, for an infection rate of 0.06%. Of those "breakthrough" cases, only 195 had to be hospitalized and 21 have died, she said.

As of Friday, the rolling seven-day average rate of people testing positive for the virus was 2.4%, down slightly from 2.5% reported Thursday but above the 1.5% rate from a week ago and the 0.3% from mid-June.

The county reported five new COVID deaths on Friday, raising the pandemic death toll in the county to 24,530.

Rising case numbers continue to impact the county's Black residents at a much higher rate than other ethnic groups, correlating with dramatically lagging vaccination rates in the Black community. Ferrer said that from the end of May to the end of June, the rate of new infections among Black residents grew from 38 per 100,000 residents to 65 per 100,000.

All other ethnic groups saw increases during that time, but at a far lower rate. At the end of June, the rate of hospitalizations among Black residents was 9.3 per 100,000 residents, compared to 2.7 for white residents and 5.4 for Latino residents. 

While COVID vaccinations have been shown to provide strong protection against the variant, Ferrer said it is a major threat to the county's roughly 4 million unvaccinated residents, including the 1.3 million children still ineligible to get the vaccine.

Combining the large number of unvaccinated residents with the lifting of COVID health restrictions on gatherings and indoor capacity, Ferrer said there are far more opportunities for those residents to become infected.

She said people who are unvaccinated should be adhering to infection- control measures, such as mask-wearing indoors and proper hygiene. But she said getting vaccinated is clearly the most effective way to prevent infection.

Among county residents age 16 and older, 69% have received at least one dose of vaccine, and 60% are fully vaccinated. The rate among Black residents, however, is only 45% with at least one dose, compared to 54% for Latino residents, 65% for white residents and 76% for Asians. Vaccination rates continue to be especially low among younger Black residents, with only 28% of those aged 18-29 vaccinated.

In hopes of encouraging more people to get vaccinated, the county is continuing to offer incentives. From Friday to next Thursday, anyone who gets vaccinated at sites operated by the county, the city of Los Angeles or St. John's Well Child and Family Center will be entered for a chance to win one of seven concert ticket prizes, including box seats at the Hollywood Bowl and tickets to Staples Center concerts including Celine Dion, Grupo Firma, Luke Bryan, Kane Brown and Dan+Shay.