Travel health update
This update focuses on recent changes to the Green Book which will have an impact on travel risk assessment and advice
GREEN BOOK CHANGES
A number of changes have been made to Green Book chapters over the past months and one significant development is that, if the chapter relates exclusively to a travel vaccine, it is now available on the TravelHealthPro website at https://travelhealthpro.org.uk/factsheet/109/the-green-book-travel-chapters. Other chapters are available from the Green Book Immunisation against infectious diseases collection at https://www.gov.uk/government/collections/immunisation-against-infectious-disease-the-green-book.
Chapter 20 on Japanese encephalitis, updated in February 2024, includes a new algorithm showing the decision making process for Japanese encephalitis vaccination in line with the current UK recommendations. This is a helpful tool and is found on page 5. JE is rare in British travellers but there have been cases in unvaccinated travellers that resulted in severe neurological illnesses and long-term sequelae.1
Chapter 35 on Yellow fever (YF) was updated in February and again in March 2024, to include an update on egg allergy and comprehensive advice. Egg allergy is a ‘relative contraindication’ to YF vaccine. You should include any history of egg allergy in the traveller’s risk assessment. There could be a number of options, so read the advice on page 8. Guidance from the Society of Cardiothoracic Surgery has been added to clarify contraindications to YF vaccine following thymectomy and cardiac surgery. In people who had cardiac surgery prior to 2000, YF vaccine is contraindicated as thymic fat used to be routinely removed. Again ensure you refer to the relevant information on page 8 for more details. Figure 35.1 on Reinforcing immunisation, on page 5, includes more details, and a footnote states that reinforcing immunisation is recommended for children once they reach 2 years or older, depending on the next planned travel to a risk area. Seroprotection rates wane 3 months to 5 years following primary vaccination in some children who are vaccinated under 2 years of age.
Chapter 18 on Hepatitis B was updated in May. In relation to travel, my interpretation is that most adult and childhood risk groups (this excludes infants who had three doses of the 6-in-1 vaccine in the childhood immunisation programme) should be given a 0, 1, 2 month schedule of hep B vaccine. The latest update now advises giving a further dose at 12 months, whereas in the last edition it 'considered giving the 12 month dose only for those in certain risk categories’.
I have updated my travel vaccine chart to reflect these changes – see item 3 at https://www.janechiodini.co.uk/tools/
VACCINES AWAITING GREEN BOOK UPDATES
Verorab® is now licensed as a pre-exposure rabies vaccine in the UK, with a schedule of two doses 0.5ml (IM) on days 0 and 7. The vaccine is also now licensed for intradermal (ID) use (0.1ml). Commenting on current rabies vaccine shortages, TravelHealthPro said that the new licence was not included in the Green Book, and that the IM route was preferred, although the ID administration route is approved by the WHO. Verorab is included in the updated Rabies Factsheet (June 2024) on TravelHealthPro for an IM route on a 3 dose schedule on days 0, 7 and 21 or 28 only. https://travelhealthpro.org.uk/factsheet/20/rabies. TravelHealthPro also comments that a two-dose schedule would be considered as partially immunised in the UK. See https:/travelhealthpro.org.uk/news/741/rabies-vaccine-shortage-advice-for-health-professionals.
Qdenga® dengue vaccine guidance was posted on TravelHealthPro in March 2024 – see https://travelhealthpro.org.uk/news/763/qdenga-dengue-vaccine-guidance. Green Book guidance is awaited at the time of writing, but currently the JCVI states that Qdenga® vaccination cannot be advised for seronegative individuals in the UK. This means that if you have a traveller who has never had dengue before, they should not be offered vaccine. It is really important to read this news item to understand more. Dengue is spreading significantly around the world so it’s also important to provide stringent mosquito bite avoidance advice to your travellers.
1. Turtle L, et al. J Travel Medicine 2019;26(7);taz064. https://academic.oup.com/jtm/article/26/7/taz064/5554873