Vaccines to prevent rabies in people are in short supply in the United States and should be used only if needed, federal health officials advised on Thursday.
So people should only get the vaccine if there is a chance they have been exposed to rabies, and not ahead of possible exposures, the U.S. Centers for Disease Control and Prevention said.
Rabies is a fatal virus that can infect all mammals. Once people or animals begin to show symptoms there is no cure, and it is highly infectious.
People can become ill weeks and even months after being bitten or otherwise exposed to the virus, usually transmitted in saliva. The only way to protect against developing the disease is to vaccinate.
Renovations at vaccine maker sanofi pasteur's plant in France mean the company cannot make new vaccine there until 2009, the CDC said.
"Prior to these renovations, sanofi pasteur established an inventory based on historical levels of sales and projected market demand," the CDC said in a statement, released to a meeting of its Advisory Committee on Immunization Practices.
"The facility is scheduled to be approved and operational by mid-to-late 2009. Until the facility is operational, sanofi pasteur has only a limited of Imovax Rabies vaccine."
Sanofi pasteur is a unit of Sanofi Aventis, the world's third-largest pharmaceutical company.
Novartis, the other supplier of rabies vaccine for the United States, cannot make enough rabies vaccine to meet projected needs, the CDC said.
"Since early 2008, Novartis has been supplying its rabies vaccine, RabAvert, for post-exposure use only. Consequently, sanofi pasteur has been supplying nearly all of the market for rabies vaccine. The increase in demand for Imovax is outpacing the company's historical levels of supply," the CDC said.
The CDC said all dogs, cats and ferrets should be vaccinated against rabies, and perhaps valuable livestock and horses. "Animals that have frequent contact with humans should be vaccinated," the CDC said.
Rabies kills 55,000 people a year globally, according to the World Health Organization.
Only one person — a Wisconsin girl who was put into an intentional coma in 2004 — has ever been known to have survived rabies infection.