nIf an extract is shown – using in vitro or in vivo data – to be
cross-reactive to another extract for which adequate
efficacy data exist, then the cross-reactive extract
may be considered to be effective as well.
nPartial cross-reactivity is acceptable.
nWhen quantitative cross-reactivity data are provided,
the degree of cross-reactivity should be no less than 20%
for allergens of the same genus.
nFor allergens of different genera, the minimum level of cross-reactivity
should be higher.
nWhen cross-reactivity data among two or more extracts of the
same genus are especially convincing, then additional
members of the same genus may be determined to be
cross-reactive.
n