A shortage of influenza vaccine has persisted this season, according to the American Health Care Association.

Chiron Corp. said it would not be able to produce as much vaccine as it anticipated. As a result, providers and distributors received less vaccine than they had ordered from the company. While some communities and providers have had sufficient supplies of vaccine, others may not have received much. More than 78 million flu vaccine doses were produced and distributed in the United States as of the end of November.

The last doses of vaccine are being produced and are available this month as part of the Centers for Disease Control and Prevention flu vaccine stockpile.