. 2011 Jan 5;85(6):2851–2858. doi: 10.1128/JVI.01939-10

TABLE 5.

Semiquantitative scoring for histopathology in lungs of ferrets 4 days after infection with pH1N1

Group	Immunization		Avg^a
	Immunization		Score (1 to 3)		% Positive slides			Score (1 to 3)
	First	Second	Extent of alveolitis/alveolar damage	Severity of alveolitis	Alveolar edema	Alveolar hemorrhage	Type II pneumocyte hyperplasia	Severity of bronchitis/bronchiolitis	Degree of perivascular/peribronchial cuffing	Severity of tracheitis
1	sVacMF59	pVac	1.92	1.13	17	0	100	2.21	2.13	1.17
2	sVacMF59	pVacMF59	1.58	0.96	4	0	100	1.13	1.58	1.17
3	sVac	sVac	2.85	1.55	65	35	95	2.00	2.05	0.17
4	sVac	pVac	2.29	1.33	50	8	100	2.04	2.08	0.50
5	sVac	pVacMF59	1.92	1.25	17	0	100	2.00	1.79	0.80
6	PBS	pVacMF59	2.50	1.29	13	0	100	1.96	2.04	1.30
7	PBS	PBS	2.75	1.79	88	17	100	1.67	1.63	0.50

Scores and values were determined as follows. Extent of alveolitis and alveolar damage: 0, 0%; 1, 25%; 2, 25 to 50%; and 3, >50%. Severity of alveolitis: 0, no inflammatory cells; 1, few inflammatory cells; 2, moderate numbers of inflammatory cells; 3, many inflammatory cells. Alveolar edema: 0, no; 1, yes. Alveolar hemorrhage: 0, no; 1, yes. Type II pneumocyte hyperplasia: 0, no; 1, yes. Severity of bronchiolitis, bronchitis, and tracheitis: 0, no inflammatory cells; 1, few inflammatory cells; 2, moderate numbers of inflammatory cells; 3, many inflammatory cells. Extent of peribronchial, peribronchiolar, and perivascular infiltrates: 0, none; 1, one to two cells thick; 2, three to ten cells thick; 3, more than 10 cells thick.