Seasonal flu clinics at Yale are now on hold until further notice, University Health Services officials said in an e-mail to the Yale community Wednesday.

The clinics have been shut down because YUHS officials received only half of the 15,000 doses they ordered from the state Department of Health last spring, and they do not have enough doses for the entire Yale community, the YUHS e-mail said. Production delays are not uncommon, the officials added, but this year the onset of the H1N1 influenza virus, more commonly known as swine flu, has prompted manufacturers to prioritize swine flu vaccine production over seasonal flu vaccine production.

YUHS officials said the University-owned seasonal flu doses will be distributed to high-risk patients — including health-care personnel and young adults — in accordance with official recommendations from the Centers for Disease Control.

“Retooling [vaccine production] to make and distribute H1N1 vaccine is an industry and public health priority,” YUHS Associate Director Peter Steere wrote in an e-mail. “Channels for seasonal product have, if not dried up, been put on hold for the moment.”

Given the severity of last year’s flu season, Steere wrote, YUHS officials anticipated heavier than usual demand this season. (He added that YUHS officials have ordered even more dosages to supplement the original order, despite the delay.) Officials from Yale’s vaccine providers, Sanofi Aventis, expect to fulfill the rest of the vaccine orders by November at the latest, Steere wrote, though they will continue to ship vaccines as they become available.

CDC spokeswoman Amanda Aldridge said in an interview Wednesday that it is unclear when Yale will receive more vaccines. But she added that students need not fear this flu season.

“Enough flu vaccines have been ordered to accommodate anyone who would like a vaccine or who should get one,” she said.

Besides, the delivery delay is nothing new; sometimes, there are snags in production. For instance, CDC officials may incorrectly predict the dominant flu strain, causing manufacturers to produce ineffective vaccines from the outset, Steere wrote.

“Every year, it seems, there is some issue affecting the supply or efficacy of flu vaccine,” he added.