Proportions of IgG Subclasses in Antibodies Formed during Vaccination with Hepatitis B Surface Antigen

Abstract
Nineteen healthy adults were given three injections of hepatitis B vaccine (days 0, 30. and 180), and serum samples were obtained on days 0, 21. 51. and 201. A fourfold or greater increase of IgG antibodies within 201 days was detected in 18 individuals (geometrical mean increase 26‐fold). but final IgG antibody concentrations (0.3‐3μgml) were low Some vaccinees had almost reached peak concentration on day 21. in others a great increase was observed between days 21 and 51. and in a few individuals between days 51 and 201. IgG1 was the predominant subclass in the antibodies of most individuals Ninety‐five percent of all IgG antibodies were IgG1 in early samples of early responders. In late samples of all vaccinees the average proportion of IgG1 antibodies was 78% The proportion of IgG2 antibodies was slightly higher in late samples (average 12%) than in the early samples of the early responders. (average less than 6%, P<0.05). Considerable amounts of IgG3 and IgG4 antibodies were found in one vaccinee, but on the average the proportion of IgG3 or IgG4 antibodies was low (less than 6%).