Simplify the following text for a Grade 10 native English-speaking person.
Original: Active anaphylaxis is what is naturally observed . Two weeks or so after an animal , including humans , is exposed to certain allergens , active anaphylaxis ( which is simply called `` anaphylaxis '' ) would be elicited upon exposure to the same allergens .
Simplified: Very small amounts of allergens can still cause anaphylaxis .