(The Hill) — The Centers for Disease Control and Prevention is advising doctors to conserve a certain type of tetanus shot in anticipation of shortages after one of its two manufacturers stopped production. 

Two tetanus and diphtheria (Td) vaccine products have been available for use in the United States: one made by Sanofi, and one made by MassBiologics, which is the sole Td vaccine manufacturer in the country. According to the CDC, MassBiologics has discontinued its shot.

“Sanofi is taking steps to augment their available U.S. supply,” the CDC said, but it will take time and the agency said it anticipates “that the supply of Td vaccine in the U.S. market will be constrained during 2024.” 

Grifols, which is the exclusive distributor for the MassBiologics shot, expects to have product available only through about June, the agency said. 

Temporary ordering controls are in place in the public and private sectors to help manage the gap in supply. CDC said doctors should switch to giving the broader Tdap vaccine instead whenever possible. In addition to tetanus and diphtheria, the Tdap vaccine also offers protection against pertussis, also known as whooping cough.

Tetanus shots are often given as a booster dose every 10 years, though doctors are recommended to give them earlier when treating severe or dirty wounds and burns. Tdap vaccine is an acceptable alternative, the CDC said, including when a tetanus booster is indicated for wound management. 

The use of Td vaccines has been declining in recent years, according to CDC data, though it is less expensive than the Tdap shot.

There are two licensed manufacturers of Tdap vaccines, and the CDC said there are no supply constraints.