Yellow fever vaccination in egg-allergic patients

Abstract

Yellow Fever Vaccine is contraindicated in egg-allergic people. However, under certain circumstances, its administration may be possible and advisable. We present two clinical cases of egg allergic children who were vaccinated against yellow fever following a short staggered administration protocol of the vaccine at a specialized hospital Unit. We explain the vaccination protocol applied in the Allergy Unit of Rio-Hortega University Hospital, Spain, with the coordination of The International Vaccination Centre.

Yellow Fever Vaccination in Egg‐allergic Children

“…Vaccination of egg-allergic individuals has been described in the literature, using a variety of skin testing and desensitisation protocols. There is very little data to support the safety of yellow fever vaccine in egg-allergic children, particularly those with severe egg allergy [2][3][4] .…”

Frequency of allergic reactions in egg allergic patients after receiving the yellow fever vaccine

“…However, the global incidence might be 10-250 times greater. 1 Since its introduction, the yellow fever vaccine (YFV) has proven to be the most effective way to prevent this disease, [1][2][3][4][5][6][7][8] granting 90% protection 10 days after its administration, and a single lifetime dose is sufficient. [1][2][3][4][5]8 YF vaccination is, therefore, important and required for residents and travelers of endemic regions.…”

“…1 Since its introduction, the yellow fever vaccine (YFV) has proven to be the most effective way to prevent this disease, [1][2][3][4][5][6][7][8] granting 90% protection 10 days after its administration, and a single lifetime dose is sufficient. [1][2][3][4][5]8 YF vaccination is, therefore, important and required for residents and travelers of endemic regions. 5,9,10 The WHO contraindicates the YFV application in patients with severe egg allergy, 1 and the manufacturers contraindicate its application in all egg-allergic patients (EAP), [11][12][13][14][15] as its cultivation in embryonated-chicken-eggs may represent a higher risk of adverse reactions in these populations because it contains residual ovalbumin and other egg proteins.…”

“…10 It is indicated that EAP should be evaluated by allergy specialists to determine if the vaccine ought to be administered in a single dose or graded doses, and/or at a specialized attention center. 4,[16][17][18] These recommendations can be barriers leading to delays or even abstention of vaccination, increasing the risk of exposure in endemic regions. 19 Other vaccines are also produced in chickenembryos (e.g., Influenza) or chicken-fibroblasts (e.g., MMR, Rabies).…”

“…19 Other vaccines are also produced in chickenembryos (e.g., Influenza) or chicken-fibroblasts (e.g., MMR, Rabies). 4,16,17,[19][20][21][22][23][24] Vaccines produced in embryos have greater concentrations of residual egg proteins than those produced in fibroblasts. 4,16,20 Recent evidence has demonstrated that vaccination of EAP with Influenza (ovalbumin ≤1.0-1.6 ug/dose) 25 and MMR (ovalbumin ≤ 1.0 ng/dose) 25 is not associated with an increased frequency of allergic reactions in contrast with non-EAP.…”