MRSA	Methicillin-resistant Staphylococcus aureus
IAV	Influenza A virus
BALF	Bronchoalveolar lavage fluid
SIgA	Secretory IgA
TD	T cell-dependent
TI	T cell-independent
BAFF	B-cell activating factor
APRIL	A proliferation-inducing ligand
PR8	Influenza virus strain A/Puerto Rico/8/34 (H1N1)
TCID50	50% tissue culture infective dose
CFU	Colony forming units
SPF	Specific pathogen free
ABX	Antibiotic cocktails
H&E	Hematoxylin-eosin