First evidence of gregarious denning in opossums (Didelphimorphia, Didelphidae), with notes on their social behaviour.

The Didelphidae are considered solitary opossums with few social interactions, usually limited to mating-related or mother-pouch young interactions. Anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. Here, we report novel observations that indicate opossums are more social than previously thought.

Can multiple doses of BCG vaccine protect against asthma?

Objective: To compare BCG vaccination involving a single intradermal dose and that involving multiple doses, one given with the multiple puncture technique, in terms of the protective effect against the subsequent onset of asthma.

Methods: A retrospective cohort study involving 2,311 individuals having received the BCG vaccine. The patients were classified according to the number of doses of BCG vaccine administered (one; two; or three or more).