Updated Recommendations for the Use of Typhoid Vaccine — Advisory Committee on Immunization Practices, United States, 2015

Brendan R. Jackson, MD; Shahed Iqbal, PhD; Barbara Mahon, MD


Morbidity and Mortality Weekly Report. 2015;64(11):305-308. 

In This Article

Adverse Reactions

Evidence from trials and postmarketing studies suggest that parenteral Vi vaccines are usually tolerated well.20. In field trials, pain (risk ratio [RR] = 8.0; CI = 3.7–17.2) and swelling at the injection site (RR = 6.0; CI = 1.1–34.2) were more common among vaccinees than placebo recipients, but no significant difference was found in the incidence of fever or erythema.[13] In a manufacturer-funded postmarketing safety study conducted in 11 U.S. travel clinics, the most common reactions were injection site pain (77%), tenderness (75%), and muscle aches (39%).[22] In postmarketing surveillance of the Vi vaccine (administered alone or simultaneously with other vaccines) during 1995–2002, an estimated 0.3 serious events* per 100,000 doses distributed were reported to the U.S. Vaccine Adverse Events Reporting System (VAERS).[23] Among the 321 VAERS reports of events occurring after Vi vaccination, the most commonly reported symptoms included injection site reactions, fever, headache, rash, urticaria, abdominal pain, and nausea. It is important to note that adverse events reported to VAERS might not be caused by the vaccine.

In a meta-analysis of Ty21a vaccine placebo-controlled trials, fever was more common among vaccinees (RR = 1.8; CI = 1.0–3.1), but other adverse events occurred with equal frequency among groups receiving vaccine and placebo; risk for any mild adverse event was higher among vaccinees (RR = 1.7; CI = 1.0–2.7).[13] In a combined analysis of data from a pilot study and a field trial, fewer than 10% of vaccinees reported abdominal pain (6.4%), nausea (5.8%), headache (4.8%), fever (3.3%), diarrhea (2.9%), vomiting (1.5%), or skin rash (1.0%).[21,24,25] One nonfatal case of anaphylactic shock, which was considered to be an allergic reaction to the vaccine, was reported to the manufacturer.[21] In VAERS postmarketing surveillance of the Ty21a vaccine (administered alone or simultaneously with other vaccines) during 1991–2002, an estimated 0.6 serious events per 100,000 doses distributed were reported.[23] Among the 345 reports of events occurring after Ty21a vaccination, the most commonly reported symptoms included diarrhea, nausea, fever, abdominal pain, headache, rash, vomiting, and urticaria.[23]

*Serious adverse events were defined as reports of death, hospitalizations, prolongation of hospitalization, permanent disability, life-threatening illness, or congenital anomaly.