The Advisory Committee on Immunization Practices voted unanimously to accept proposed updates to the recommendations for typhoid vaccines.
There are no changes to the guidelines in terms of the populations recommended to receive the vaccine. The updated statement reflects changes in vaccine availability, new data on the epidemiology of typhoid and new data on vaccine safety and efficacy. The typhoid vaccine statement had not been updated since 1994.
Brendan Jackson, MD, MPH, medical epidemiologist in the CDC’s Enteric Diseases Epidemiology Branch, said the statement will now reflect that there are two vaccine options: Ty21a (Vivotif, Crucell), an oral, four-dose, live-attenuated vaccine; and the Vi capsular polysaccharide vaccine (ViCPS), an injectable, one dose, subunit vaccine. Ty21a is indicated for patients aged 6 years and older and ViCPS is indicated for patients aged 2 years and older.
Typhoid vaccine remains recommended for travelers to areas where there is a recognized risk for exposure to Salmonella Typhi, which normally is acquired by contaminated food or water, Jackson said. Humans are the only reservoir for Salmonella Typhi, he said. The vaccine also is recommended for household contacts of a chronic carrier of Salmonella Typhi and for laboratory workers who frequently work with Salmonella Typhi cultures or specimens.
“Globally, there are approximately 20 million cases of typhoid fever per year and 200,000 deaths,” Jackson said during his presentation. “Multidrug resistance is common for Typhi, and emerging resistance threats highlight the increased importance of vaccination.”
In the United States, there are approximately 400 cases of typhoid fever annually, and 90% of the cases are associated with travel, primarily to South Asia, Jackson said.