Immunization Route/Method | IgG2a/IgG1 |
|---|
4 weeks | 9 weeks (no boost) | 9 weeks (1 boost) | 12 weeks (no boost) | 12 weeks (2 boosts) |
|---|
IM | 1.2 | − | − | 2.7 | 3.2 |
ID | 0.2 | − | − | 0.9 | 1.3 |
GG | 0.01a | 0.003a | 0.002 | − | − |
- BALB/c mice were immunized by IM or ID injection with 100 µg pCMV-S2.S or by GG delivery with 1.6 µg. At 4 and 6 weeks some mice were boosted in an identical manner to prime. HBsAg-specific antibodies of IgG1 or IgG2a isotypes were determined by end-point dilution ELISA assay in plasma taken at various time points after immunization. Titers were defined as the highest plasma dilution resulting in an absorbance value two times that of nonimmune plasma, with a cut-off value of 0.05. The IgG2a-to-IgG1 ratios were determined, with a value >1 indicating a predominantly Th-1 like response.
- aThere was no detectable IgG2a with these groups, thus a value of 1 was assigned for IgG2a to determine IgG2a/IgG1.
