TABLE 1.

Percent distributions of measles virus-specific IgG isotypes in the population studied

Study group (source, phase of measles infection)	Time after onset of rash	Total no. of samples	Mean % (range) of isolates seropositive fora:
			IgG1	IgG2	IgG3	IgG4
1a (natural, acute)	0-7 days	32	94 (87-100)	34 (27-41)	44 (37-51)	50 (40-54)
2a (postvaccinal, acute)	0-7 days	15	100 (89-100)	13 (2-24)	40 (29-51)	68 (56-78)
1b (natural, convalescence)	8-26 days	22	100 (91-100)	64 (55-73)	72 (63-81)	96 (87-100)
2b (postvaccinal, convalescence)	8-30 days	13	100 (88-100)	54 (42-66)	70 (58-82)	92 (80-100)
3 (natural, long-lasting immunity)	10-80 years	100	100 (94-100)	2 (0-8)	3 (0-9)	86 (80-92)
4 (postvaccinal, long-lasting immunity)	8-12 years	76	100 (93-100)	2 (0-9)	7 (0-13)	9 (2-16)

^a95% CI.