Getting first COVID shot continues to be a challenge in L.A.

COVID-19 vaccine appointments may remain a precious commodity in Los Angeles County this week, with many slots reserved for second doses as officials continue to contend with a supply crunch.

At county-run sites — which include the Pomona Fairplex, the Forum in Inglewood, Cal State Northridge, the county Office of Education, Six Flags Magic Mountain, the Balboa Sports Complex, El Sereno Recreation Center and the Antelope Valley Health Center — “the remainder of appointments this week are dedicated to providing second doses,” the L.A. County Department of Public Health tweeted Sunday.

The bottleneck, however, is not expected to be anywhere near as severe at sites run by the city of Los Angeles, such as those at San Fernando Park, Hansen Dam, Crenshaw Christian Center, Lincoln Park, Pierce College, USC University Park and Dodger Stadium.

City officials say they will offer more than 70,000 shots this week, with about 50,000 available for first doses.

“Each Angeleno vaccinated moves us closer to reopening our businesses, getting kids back in the classroom and returning to the embrace of family and friends,” Mayor Eric Garcetti said in a statement. “Our city is determined to get shots into people’s arms as swiftly and safely as possible because we know that’s the best path to ending this pandemic once and for all.”

Two of the COVID-19 vaccines being used in the United States — one from Pfizer-BioNTech and the other from Moderna — require two doses, administered weeks apart.

As a result, health officials have for months had to balance the desire to vaccinate as many people as possible, as quickly as possible, with ensuring that there’s sufficient supply down the line for people to complete their two-shot regimen.

For much of the COVID-19 vaccine rollout, health officials in L.A. County and across the state have been singing a similar refrain: that the supply of doses coming in is not only insufficient to meet demand but also much less than providers can reliably administer.

This week, for instance, L.A. County anticipates receiving somewhere in the neighborhood of 280,000 doses.

But Dr. Paul Simon, chief science officer with the county Department of Public Health, said Friday that more than twice that number of doses could be administered each week, if there was sufficient supply.

California as a whole expects to receive roughly 1.8 million doses this week — up slightly from last week’s allotment, according to Gov. Gavin Newsom.

But weekly shipments of that size aren’t enough to keep up with the state’s recent breakneck vaccination pace.

The last eight days have seen the eight highest single-day totals of shots administered statewide, data compiled by The Times show. During just that stretch, providers doled out 3.1 million doses, an average of almost 388,000 per day.

Overall, more than 14.8 million doses of vaccine — about 81% of the supply that’s been delivered to local public health departments and medical providers — have been administered statewide, according to the California Department of Public Health.

And many officials are striking an optimistic tone that the vaccine valve may be significantly loosened in the not-too-distant future.

Earlier this month, President Biden said restrictions on who could make a COVID-19 vaccine appointment would be lifted nationwide by May 1, as supply is expected to be sufficient to meet demand.

And Newsom said Friday that state officials anticipated being able to make the shots available to everyone “within 5½ weeks … because supply will exponentially increase.”

Nearly half of all Californians — including adults 65 and older, healthcare workers, educators, people who are incarcerated or living in homeless shelters, essential workers such as those in the food industry or emergency services, public transit workers and janitors, and residents 16 and older who have certain disabilities or underlying health conditions — are already eligible to receive the vaccine.

A key factor in widely expanding access in the near term will be the availability of another vaccine, from Johnson & Johnson. Unlike the other offerings, it requires only a single shot, which would help dramatically accelerate the pace of inoculations.

Shipments of that vaccine have been stymied by production issues, however. L.A. County, for instance, only anticipates getting about 6,000 Johnson & Johnson doses this week.

Officials are confident that a wider supply stream is on the horizon, though.

“We expect to receive much larger quantities of the Johnson & Johnson vaccine beginning at the end of this month,” Simon said.

Other vaccines also remain in the pipeline. One manufactured by AstraZeneca — which is already being used in other countries — was found to be 79% effective at preventing any COVID-19 symptoms and 100% at preventing severe ones, and had no safety issues with blood clots in large-scale U.S. trials, the company said Monday.

AstraZeneca would still need to apply for emergency-use authorization in the United States, a process that would entail scrutiny by the U.S. Food and Drug Administration, including a public debate on the scientific evidence by a committee of experts.

Despite the promising progress on the vaccine front, officials stress that residents must maintain their vigilance to stave off another coronavirus surge.

That’s especially true as more states reopen their economies more widely, lifting pandemic-related restrictions — a delicate process that experts warn can easily go awry.

Dr. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, said Monday that “the continued relaxation of prevention measures while cases are still high and while concerning variants are spreading rapidly throughout the United States is a serious threat to the progress we have made as a nation.”

“Believe me, I get it,” she said during a briefing. “We all want to return to our everyday activities and spend time with our family, friends and loved ones, but we must find the fortitude to hang in there for just a little bit longer. We are at a critical point in this pandemic, a fork in the road where we as a country must decide which path we are going to take. We must act now. And I am worried that, if we don’t take the right actions now, we will have another avoidable surge — just as we are seeing in Europe right now and just as we are so aggressively scaling up vaccination.”

California, however, is continuing to see its coronavirus metrics trend in the right direction.

Over the last week, California has reported an average of 2,702 new coronavirus cases per day, a 37% decrease from two weeks ago, according to data compiled by The Times.

Statewide, 2,605 coronavirus-positive patients were hospitalized Sunday, with 674 of them in intensive care. Both those figures have returned to levels not seen since the beginning of California’s devastating fall-and-winter wave.

The number of newly reported COVID-19 deaths also continues to decline but is not yet down to pre-surge levels. An average of 174 Californians have died from the disease every day over the last week, and the state’s total death toll has now surpassed 57,000.

Times staff writers Henry Chu and Chris Megerian contributed to this report.