Travelers who need yellow-fever vaccination may face delays

The United States continues to have some shortages of the vaccine against yellow fever, and travelers who need the vaccination may face delays in getting it.

A yellow-fever vaccination is required for entry to many countries in Africa and some South American countries, including Brazil, if travelers are arriving from an infected area. U.S. health authorities also recommend travelers get vaccinated against the viral disease when traveling to many parts of Africa and South America, even if it isn't legally required.

At some travel-medicine clinics, the supply has been spotty.

"We have some this week; last week we were out," said Christopher Sanford, co-director of the University of Washington's Travel Clinic. "This is a major problem as some countries require proof of vaccination [for yellow fever] prior to issuing a visa."

The severity of yellow fever, transmitted to humans by infected mosquitoes, ranges from relatively mild to fatal.

There is only one manufacturer of yellow-fever vaccine in the U.S., and in recent months that company, Sanofi Pasteur, has had a shortage of the single-dose vials of vaccine. Five-dose vials of vaccine have usually been available, but medical clinics must carefully schedule vaccinations for travelers since the vaccine, once reconstituted, must be used within one hour, according to the U.S. Centers for Disease Control.

Travelers who need a yellow-fever vaccination should seek it well ahead of time. The vaccine-supply shortage is expected to even out later this spring.

Kristin Jackson: kjackson@seattletimes.com