Recombinant expression of receptor binding domains of all eight subtypes of botulinum neurotoxin type A for generation of antitoxins with broad reactivity.

Background: Botulinum neurotoxin type A (BoNT/A) represents a major threat to global public health because of its most potent toxicity with the longest persistence. Several camelid single-domain antibodies (or VHHs) have been reported to exhibit high neutralizing activity against the receptor binding domain (H ) of the BoNT/A subtype used to generate them. However, it remains unclear if these VHHs can neutralize effectively H of other BoNT/A subtypes.