A guide to getting the COVID-19 vaccine for Californians 50 and over. It all begins Thursday

The threshold for COVID-19 vaccine eligibility continues to expand this week. On Thursday, all Californians age 50 and over will qualify. In some parts of the state, that batch of residents has already been greenlighted.

But eligibility doesn’t guarantee immediate access. State and local officials have been optimistic that vaccine allocation will increase significantly over the next several weeks but have warned that supply will continue to be constrained as competition for shots grows by the millions.

Here’s what you should know.

Who qualifies for a vaccine in California?

Roughly half the residents of the state currently qualify. On Thursday, that number will grow exponentially when all residents 50 and older reach eligibility. And two weeks later, on April 15, the state’s vaccine rollout will become a free-for-all, when residents 16 and over will qualify.

Right now, eligibility under state guidance includes healthcare workers, adults 65 and older, individuals with high-risk disabilities and underlying health conditions, educators and child-care workers, food service workers, those who work in incarceration facilities or homeless shelters, public transit workers, emergency service workers and vaccine clinic volunteers, among others.

Some local health jurisdictions have already expanded eligibility beyond the state guidance. The counties of Contra Costa, Butte and Stanislaus, for example, announced they would lower the age threshold to 16; the city of Long Beach and counties of San Luis Obispo and Solano have lowered it to 50. In some counties, certain health conditions beyond what the state has specified merit eligibility; San Francisco, for example, is vaccinating anyone who is HIV-positive, and San Diego is vaccinating anyone with asthma or Type 1 diabetes.

How can I get an appointment?

Newly eligible residents may have to wait a bit longer before they can lock down an appointment. The state’s My Turn scheduling site is allowing residents in L.A. County and elsewhere who are eligible on Thursday to start signing up for appointments on Wednesday, though time slots have been scarce.

State or local hotlines could be of assistance. The state’s COVID-19 hotline — at (833) 422-4255 — is open from 8 a.m. to 8 p.m. Monday through Friday and from 8 a.m. to 5 p.m. Saturday and Sunday. In Los Angeles County, those with disabilities or without computer access are encouraged to call (833) 540-0473 between 8 a.m. and 8:30 p.m. Monday through Sunday.

Here is a list of other methods to try to get an appointment.

What is the current supply outlook?

The state’s vaccine allocation has steadily grown to about 1.8 million doses per week, and with the additional distribution of more Johnson & Johnson vaccine, that estimate will increase.

Supply is expected to increase significantly up to May 1 — the date President Biden said every adult in the U.S. would be eligible for a shot. On Monday, Biden said that a record 33 million doses would be distributed across the country this week.

In L.A. County, officials said Friday they expect to receive about 338,100 doses — the highest weekly allotment to date. Still, that won’t be enough to immediately accommodate all newly eligible people.

“Even with an increased supply of vaccine, we certainly can’t handle close to a million people over that first week, given all the other groups that are also currently being vaccinated,” L.A. County Chief Science Officer Dr. Paul Simon said Friday. “But I would expect, over the following several weeks, the demand will diminish a bit, and things will open up, particularly as this vaccine supply continues to increase. And so I urge people to just be patient.”

The state has administered about 17.6 million doses to date. Roughly 29.3% of residents have received at least one dose, and 14.3% have been fully vaccinated, according to a Times analysis.

Why is eligibility expanding before supply can meet demand?

As coronavirus variants spread throughout California and as other states face a new surge, officials and health experts have stressed the need to quickly vaccinate the masses.

L.A. County Health Services Director Dr. Christina Ghaly said last week that projected transmission in the county has increased slightly. It’s too soon to say what has led to that change, and it remains unclear whether vaccinated individuals can be asymptomatic carriers of the virus.

Officials and health experts remain hopeful that vaccine supply will increase. But meanwhile, reports continue to emerge of leftover doses due to vaccine hesitancy or barriers to access. Expanded eligibility means that a greater pool of people are capable of getting the shot when it’s available, and when allocations do increase, supply will be on par with demand.

Times staff writer Luke Money contributed to this report.