Review of current typhoid fever vaccines, cross-protection against paratyphoid fever, and the European guidelines

ABSTRACT

Introduction: Typhoid and paratyphoid fever remain a global health problem, which – in non-endemic countries – are mainly seen in travelers, particularly in VFRs (visiting friends and relatives), with occasional local outbreaks occurring. A rise in anti-microbial resistance emphasizes the role of preventive measures, especially vaccinations against typhoid and paratyphoid fever for travelers visiting endemic countries.

Areas covered: This state-of-the-art review recapitulates the epidemiology and mechanisms of disease of typhoid and paratyphoid fever, depicts the perspective of non-endemic countries and travelers (VFRs), and collectively presents current European recommendations for typhoid fever vaccination. We provide a brief overview of available (and developmental) vaccines in Europe, present current data on cross-protection to S. Paratyphi, and aim to provide a background for typhoid vaccine decision-making in travelers.

Expert commentary: European recommendations are not harmonized. Experts must assess vaccination of travelers based on current country-specific recommendations. Travel health practitioners should be aware of the issues surrounding vaccination of travelers and be motivated to increase awareness of typhoid and paratyphoid fever risks.

KEYWORDS:

• Paratyphoid fever
• Ty21a
• typhoid fever
• vaccine recommendations
• Vi capsular polysaccharide
• visiting friends and relatives

Acknowledgments

Medical writing support provided by Lyndsey Kostadinov and Catherine Evans from Medicalwriters.com, Zurich, Switzerland.

Declaration of interest

The institution to which A Kantele belongs to has received an investigator-initiated grant to study cross-reactivity or oral and parenteral typhoid vaccines in 2010/2011, of which all data is published. The institution has also received consulting fees/honorarium from Crucell for consulting on immunology of typhoid vaccines in 2010/2011. The author, A Kantele, has received financial support for participation in travel medicine meetings prior to 2014 from GSK (NECTM, Hamburg), Crucell (CISTM, Boston), Janssen (NECTM,Dublin) and received funding from PaxVax in 2015 to participate in CISTM, Toronto. A Kantele has also received honorarium for participation in advisory boards from Novartis (2011), Crucell (2012), Valneva (2016), and for providing lectures for Crucell, PaxVax and Valneva. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

PaxVax Switzerland funded medical writing support of the manuscript.