MHRA warns of yellow fever vaccine risk
The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a warning following two recent reports of fatal adverse reactions to the yellow fever vaccine (Stamaril).
In one case, the vaccine was given to a person who had undergone a thymectomy following a thymoma. This is a listed contraindication in the summary of product characteristics. The second case was a person aged 67 years old with no other known risk factors. Both of these people died shortly after vaccination, due to suspected yellow fever vaccine-associated viscerotropic disease (YEL-AVD), a recognised adverse reaction that resembles severe yellow fever infection.
The MHRA reminds healthcare professionals that, as with any live attenuated vaccine, yellow fever vaccine must not be given to immunosuppressed patients. This is because live vaccine strains can replicate and cause a severe and sometimes fatal infection.
In addition, yellow fever vaccine is contraindicated in people with a history of thymus dysfunction (including myasthenia gravis and thymoma) or in those who have had a thymectomy. In people over the age of 60 years, the vaccine should only be given if there is a significant and unavoidable risk of yellow fever infection. If there is any doubt over whether a person is immunosuppressed (due to immunosuppressive therapy or underlying illness), immunisation with the yellow fever vaccine should be deferred until specialist advice has been sought. Those administering the vaccine should be familiar with the YF Vaccine Centre code of practice, and protocols and checklists should be strengthened to avoid inappropriate administration.
Full prescribing information, contraindications and warnings are available in the summary of product characteristics, which any healthcare professional administering the vaccine should be fully familiar with. Potential risks and benefits should be discussed with the person requesting vaccination. Further information can be found in Chapter 35 of the Green Book and on the National Travel Health Network and Centre (NaTHNaC) website.
The Commission on Human Medicines is currently reviewing the benefits and risks of yellow fever vaccine in light of these cases and recommendations will be made in due course. In the meantime, any adverse reactions should be reported to the Yellow Card Scheme.