Shared decision-making when multiple vaccines are recommended for a traveller

Author(s):  Dr Sherilyn Houle

A recent report on 1,651 pre-travel consultations performed at a clinic in the United Kingdom found that the median number of vaccine courses recommended per new consultation was 3 (range 0-10) and 93% of travellers were recommended at least one vaccine.¹ Of these, only 53.9% accepted all recommended vaccines for various reasons. In this case, it must be noted that hepatitis A, typhoid, cholera, and diphtheria/tetanus/polio vaccines are often available at no charge from primary care providers in the UK, and of those providing a reason for refusal in clinic, 46% indicated that they planned to seek a no charge vaccine from primary care. Factors significantly correlated with vaccine refusal were age ≤45 years or travelling for religion, and there was a positive linear correlation between the number of vaccines recommended overall and the number of vaccines declined.

Many factors can contribute to a patient’s decision to refuse a recommended vaccine including cost, concerns about the safety of receiving multiple vaccines concurrently, or a perception of being at low risk of the disease being prevented. Clinicians may be asked their opinion on which vaccines should be prioritized, which is challenging since values and preferences can vary across patients and may not always align with clinical risk/benefit considerations.

In a paper published in the Journal of Travel Medicine, Robert Steffen and colleagues conducted a literature search on the epidemiology of vaccine-preventable diseases among travellers including the incidence of symptomatic infection and the severity of illness based on hospitalization, sequelae, and the case fatality rate.² The result is a crosstab table that combines incidence and impact data to assist clinicians with determining overall risk for a given vaccine-preventable disease. Of the top 5 diseases based on incidence (COVID-19, influenza, dengue, animal bite with risk of rabies, and yellow fever [specifically in the 2016 Ilha Grande, Brazil, outbreak or in West Africa]), only yellow fever was also considered to have very high impact related to severity, with dengue considered intermediate and the remainder considered low.

While our aim as clinicians should be to encourage vaccination and co-administration of multiple vaccines during a clinic visit to best protect our travelling patient, this incidence versus impact table can provide an epidemiologic perspective to help inform shared decision-making with travellers who are unwilling to receive all recommended vaccines for various reasons.

References

[1].  Less is more: Uptake of recommended vaccines in a UK travel clinic.  Harrison T, Clark J, Darton TC ‐ J Infect 2024;88(3):106109 [link]
[2].  Travel vaccines-priorities determined by incidence and impact.  Steffen R, Chen LH, Leggat PA ‐ J Travel Med. 2023 Nov 18;30(7):taad085 [link]