Can Typhoid Vaccine Cause Temporary Fever?
Yes, the parenteral (injectable) typhoid vaccine commonly causes temporary fever, occurring in 14% to 29% of vaccinees, while the oral typhoid vaccine rarely causes fever and has adverse event rates comparable to placebo.
Fever Risk by Vaccine Type
Parenteral (Injectable) Inactivated Typhoid Vaccine
- Fever occurs in 14% to 29% of recipients receiving the parenteral inactivated typhoid vaccine 1
- The fever is typically accompanied by other systemic reactions including headache (9%-30% of vaccinees) and severe local pain and/or swelling (6%-40% of vaccinees) 1
- These reactions are significant enough that 13% to 24% of vaccinees missed work or school because of adverse reactions 1
- The fever and systemic symptoms typically last 1-2 days 1
Oral Live-Attenuated Ty21a Vaccine
- Side effects are rare with the oral Ty21a vaccine, and adverse reactions occurred with equal frequency among groups receiving vaccine and placebo in safety trials 1
- Adverse event rates are less than 1 per 100,000 doses administered 1
- When side effects do occur, they consist of abdominal discomfort, nausea, vomiting, and rash or urticaria—not fever 1
Vi Polysaccharide Vaccine
- The Vi polysaccharide vaccine probably does not increase the incidence of fever compared to placebo 2
- This vaccine primarily causes local reactions (swelling and pain at injection site) rather than systemic symptoms like fever 2
Clinical Implications
The fever from parenteral typhoid vaccine is self-limited and temporary, resolving within 1-2 days without intervention 1. However, clinicians should counsel patients about this common side effect, particularly those who may need to work or attend school shortly after vaccination.
For patients concerned about fever or systemic reactions, the oral Ty21a vaccine provides equivalent protection (approximately 67% efficacy) with a much lower incidence of adverse reactions compared to the parenteral vaccine 3, 2.
Important Caveat
One case report documented a fatal hyperthermia event in a patient who received typhoid vaccine while taking pseudoephedrine and then exercised shortly after vaccination 4. While this represents an extremely rare occurrence, patients should be advised to avoid strenuous exercise and thermogenic substances (like pseudoephedrine) immediately following typhoid vaccination, particularly with the parenteral formulation that commonly causes fever 4.