SAN JOSE (CBS SF) — Two different Bay Area counties will be making changes on Thursday to how residents 16 and over will sign up for a COVID-19 vaccine starting Thursday morning, though each county is taking a different approach.

Starting at midnight on April 8, Santa Clara County is making hundreds of thousands of South Bay residents eligible to sign up to get vaccinated by allowing those age 16 and up to schedule vaccine appointments.

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However, county officials said people age 16 to 50 will still have to book their appointments for after the eligibility window opens for that age group starting on April 15.

As of Wednesday evening, the Santa Clara County Health Departments COVID-19 website still showed that only those age 50 and older are eligible for the vaccination in accordance with current state eligibility criteria.

Meanwhile, Alameda County on Thursday will actually start administering COVID vaccines to people 16 and older in specific areas of Oakland, Hayward, San Leandro and San Lorenzo that have been hardest hit by the pandemic.

The 12 zip codes that are expanding the ages for vaccine eligibility are 94601, 94603, 94605, 94606, 94607, 94621, 94541, 94544, 94545, 94577, 94578 and 94580.

More information on signing up for a COVID vaccine in Alameda County is available on the county health department website.

Santa Clara County on Thursday was still trying to ensure the most vulnerable get their vaccines.

To that end, the county held a special vaccination event at Levi’s Stadium in Santa Clara for people with special needs and their family members.

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Public health officials said people with intellectual disabilities are more than two times as likely to contract COVID-19 and more than six times more likely to die from it.

Parents of children with special needs told KPIX that it was especially important for them to have an event designed specifically for them.

They said it sped them through the process and they could be confident that there would be people on hand who could deal with any problems that might arise.

“It was important that I get it in time, so I can get her at that time; without me having to go or my husband going to stand in line, get an appointment, come back home and then going,” said South Bay mother Usha Kikkeri. “This event really helped us.”

Actually getting an appointment as more and more Bay Area residents become eligible for the COVID vaccine could be another matter.

According to the Mercury News, California will receive about 90 percent fewer Johnson & Johnson vaccines next week. The state’s total vaccine allotment for next week is about two million doses, approximately 367,000 fewer doses than this week.

State health officials noted that nationwide, states are reporting a drop in vaccine allocations.

The drop can be mainly attributed to reduced allocations of the Johnson & Johnson vaccine.

While there were nearly 575,000 vaccine doses provided this week, next week than number drops to under 67,000 before dropping further still to only about 22,400 J&J shots the week of April 18.

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Devin Fehely contributed to this story.