LOS ANGELES (CNS) — With the newly provided blessing of the federal government, Los Angeles County health officials began offering third doses of Pfizer and Moderna COVID-19 vaccines Saturday for people with severely compromised immune systems. 

Among those qualifying for the booster shots are organ transplant recipients, people undergoing cancer treatment, HIV patients and people on select "immunosuppressive medications." The Los Angeles County Public Health Department urged people to consult their doctors to confirm their eligibility for the third shot, which should be administered at least 28 days following the second dose.

The third doses are being offered at vaccination sites in the county offering the Pfizer and Moderna shots. People looking for the shots will be able to simply "self-attest" that they have a qualifying medical condition.

"Studies have shown immunocompromised people are more likely to have post vaccination infection and become severely ill from COVID-19," county Public Health Director Barbara Ferrer said. "An additional vaccine dose for some people with weakened immune systems could help prevent serious illness and death.

"If you have a qualifying condition, we encourage you to speak to your health care provider about getting a third dose," she said. "We also encourage those who are close contacts of immunocompromised people to get vaccinated as soon as possible in order to protect their family members and friends who are at higher risk."

The booster shots received final approval this week from the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention.

Meanwhile, the county saw a rise in the number of people hospitalized due to COVID-19 after two consecutive days of minor decreases. There were 1,650 patients in the county with COVID-19 as of Saturday, up from 1,627 the day before. Of those patients, 400 were in intensive care, an increase over the 381 reported Friday, according to state figures.

County figures show that the vast majority of people hospitalized with COVID are not vaccinated. During the month of July, vaccinated residents represented just 13% of people hospitalized with the virus.

Los Angeles County reported another 19 COVID-19 deaths on Friday, along with 3,810 more infections. The new fatalities brought the county's overall death toll from the virus to 24,872, while the cumulative number of cases from throughout the pandemic increased to 1,342,839.

The county continue to report good news in terms of the percent of people testing positive for the virus. As of Friday, the rolling daily average rate was 4.1%, down from more than 6% just two weeks ago.

Ferrer has said the county should expect to see elevated daily numbers of new infections, given newly imposed testing requirements at many businesses and schools. But she said the testing positivity rate will hopefully remain low.

Ferrer continued to press the effectiveness of vaccines, noting that while some fully vaccinated people can still become infected with COVID, they are far less likely to become seriously ill.

Of the 5.1 million vaccinated people in the county as of Aug. 10, 21,532 have tested positive for COVID-19, for a rate of 0.42%. A total of 549 fully vaccinated people have been hospitalized, for a rate of 0.01%, and 55 have died, for a rate of 0.0011%. 

As of Aug. 8, 72% of the county's eligible residents age 12 and over have received at least one dose of vaccine, and 63% are fully vaccinated. Among the county's overall population of roughly 10.3 million people — including more than 1 million people ineligible for shots because they're under age 12 — 62% have received at least one dose and 54% are fully vaccinated.

Ferrer said statistics show that unvaccinated people are 3.6 times more likely to become infected with COVID than vaccinated people.