COVID-19 cases are rising in Los Angeles: What's behind the spike

Health officials in Los Angeles County are warning that the delta variant's spread among unvaccinated people is driving a spike in new COVID-19 infections in the county.

On Monday, the health department reported 1,059 new COVID-19 cases, a significant increase since June, when the department was consistently reporting a few hundred new infections each day. Officials are currently investigating 55 ongoing outbreaks, up 25% from the 44 outbreaks they were investigating last month.

Nearly all new cases are among people who haven't gotten a COVID-19 vaccine, according to officials.

"Over 99% of the COVID-19 cases, hospitalizations and deaths we are seeing are among unvaccinated individuals," Barbara Ferrer, Los Angeles County's director of public health, said in a statement Monday.

Young people are also contributing to the infection spike, according to Ferrer. "Of the cases reported today, nearly 87% were under 50 years old," she said.

"The COVID-19 vaccines are the most effective and important tool to reduce COVID-19 transmission and the spread of variants like the highly transmissible delta variant," she said. "Getting fully vaccinated is the way we protect you, your family and our community from COVID-19 and the delta variant."

As a state, California's vaccination rate is better than the national average. As of Monday, 63% of residents had received at least one dose, and 51% were fully vaccinated, compared with 56% of all Americans who've gotten at least one shot and 48% who are fully vaccinated, according to the Centers for Disease Control and Prevention. In Los Angeles County, 70% of residents 16 and older have gotten at least one dose of the vaccine, according to the health department. Nationally, 68% of Americans 18 and older have gotten at least one dose.

The delta variant, which was first detected in India and now has made up 51.7% of infections in the United States for the two weeks ending July 3, according to the CDC, is more transmissible than the original version of the virus and is especially dangerous for people who are unvaccinated or partially vaccinated, experts say.

In part because of fears over the variant, Los Angeles officials made waves when they reversed their guidance on masks less than a month after Gov. Gavin Newsom lifted COVID-19 restrictions in the state.

According to a statement issued by the Los Angeles County Department of Public Health on June 28, the department "strongly recommends everyone, regardless of vaccination status, wear masks indoors in public places as a precautionary measure." The department acknowledged that "fully vaccinated people appear to be well protected from infections with delta variants."