Table 1. Anti-N antibody responses primed by neonatal nasal vaccination shifted from IgG1 to IgG2a and IgA isotypes when CpG were added as adjuvant.

	Serum				BALF
Prime(a)	IgG1		IgG2a		IgA
N+LT	1694±836(b)	4/4(c)	53±19	1/4	≤3	0/5
N+CpG	493±395	3/6	3751±3397	1/6	5±2	1/6
N+LT+CpG	764±396	9/9	1523±1252	5/9	10±1	6/9
LT+CpG	46±12	2/8	≤30	0/8	≤3	0/2

^(a)Neonates were immunised i.n. at age 5–7 days as indicated (prime) and received one intranasal boost with N (10 µg) at 5 weeks. Sera and BALF were collected 7 days after the boost.

^(b)Antibody titers against N were determined by ELISA using endpoint dilution assay. Data are mean±SEM (≤30 or ≤3: not detected at the first tested dilution for sera or BALF).

^(c)Number of responders/number tested.