Influenza vaccines
Influenza vaccines include trivalent and quadrivalent inactivated
vaccines (IIV), recombinant subunit vaccine (RIV) and live attenuated
vaccine (LAIV) and mostly are grown in embryonated chicken eggs and,
consequently, might contain small amounts of egg proteins, most notably
ovalbumin, the amounts of which vary by vaccine manufacturer and lot. In
the past, egg allergy was considered a contraindication to the
administration of Influenza vaccines while, nowaday, it no longer
contraindicates it and these patients can safely be vaccinated.
In fact, there is strong evidence that children with egg allergy,
including those reporting anaphylaxis, could be safely immunized with
IIVs containing less than 1.2 μg/ml of egg protein, either in two graded
doses or in one single dose31, while a concentration
of ovalbumin < 0.24 μg/dose in LAIVs was assessed as safe for
children with egg allergy including anaphylaxis32,33.
In the absence of a prior history of anaphylaxis after egg consumption
influenza vaccines can be administered without precautions while, when
history of anaphylaxis is reported, in some guidelines it is recommended
administering the vaccine without specific
precautions34 while others recommend a prolonged
observation period to 60 minutes and the presence of an equipped
setting32,33.
A vaccine obtained from human diploid cells is also available as a safe
alternative for egg allergic individuals26.