A new look at typhoid vaccination. Information for the practicing physician
B. A. Woodruff, A. T. Pavia and P. A. Blake
US Department of Health and Human Services, Public Health Service, Centers for Disease Control, Atlanta, Ga 30333.
Most cases of typhoid fever in the United States occur in international
travelers, with the greatest risk associated with travel to Peru, India,
Pakistan, and Chile. Laboratory workers and household contacts of long-term
carriers are also at greater risk than the general population. Decisions to
the use typhoid vaccine involve weighing the risk of illness against the
risk of vaccine reactions. Until recently, the only typhoid vaccine
commercially available to US civilians was a heat-phenol-inactivated
parenteral product that is 51% to 77% effective in preventing typhoid fever
but frequently produces local pain and swelling, fever, headache, and
malaise. A new orally administered, live-attenuated vaccine, made from the
Ty21a strain of Salmonella typhi, has been recently licensed in the United
States. This vaccine provides equivalent protection with a much lower
incidence of adverse reactions. It is administered in a four-dose series
given over 7 days. Since neither vaccine offers total protection, the most
important elements in prevention of typhoid fever remain sound biosafety
precautions in laboratory workers and care in selecting food and beverages
by those traveling to areas where typhoid fever is endemic.
