SANTA CLARA (KRON) – Thousands of people had their second COVID-19 vaccine appointments canceled Thursday night due to limited supplies, according to officials.

Santa Clara County sent out letters to approximately 8,700 Kaiser patients, but not to anyone else covered by other companies.

“Like all approved vaccination providers, both Kaiser Permanente and Santa Clara County are required to vaccinate those eligible, regardless of the individual’s health plan or status of health coverage,” a Kaiser spokesperson said. “Therefore, we were surprised and disappointed to learn that only people with Kaiser Permanente health coverage had their appointments canceled by Santa Clara County.”

As of the writing of this article, it is unclear why Santa Clara County only canceled patients on the Kaiser network.

Santa Clara County also announced this week that first dose appointments have had to be curbed due to limited supply, impacting a broader range of people.

While the system lacks sufficient supply to continue widespread scheduling, Santa Clara County will continue to vaccinate agricultural workers and target other disproportionally impacted communities.

“The lack of sufficient supply from the State has been frustrating for everyone, particularly those who are eligible for the vaccine, and want to be vaccinated, but have been unable to sign up,” said Dr. Marty Fenstersheib, Testing and Vaccine Officer for the County of Santa Clara. “We have had to use almost all of the vaccines we receive for second doses and have continued to provide access for our hardest-hit communities to the greatest extent possible given ongoing shortages.”

The County expects vaccine supply may increase significantly statewide in a few weeks, including through additional supplies of the one-dose Johnson & Johnson vaccine.