Table 1.
Heterologous immunity: changes in viral titer as a consequence of prior infection
| Immunizing virus | Challenge virus | change in titer versus control |
|---|---|---|
| A. Systemic (i.p) infection | ||
| Altered viral titers in the spleen or liver | ||
| LCMV | PV | ↓93% |
| LCMV | MCMV | ↓60% |
| LCMV | VV | ↓97% |
| PV | LCMV | ↓60% |
| PV | MCMV | ↓75% |
| PV | VV | ↓98% |
| MCMV | LCMV | ↓84% |
| MCMV | PV | ↓69% |
| MCMV | VV | ↓97% |
| VV | LCMV | ↓50% |
| VV | PV | ↓21% |
| VV | MCMV | −0% |
| B. Mucosal (i.n) infection altered viral titers in the lung | ||
| LCMV | VV | ↓87% |
| MCMV | VV | ↓68% |
| INFLUENZA | VV | ↓75% |
| INFLUENZA | LCMV | ↑400% |
| INFLUENZA | MCMV | ↑500% |
LCMV, lymphocytic choriomeningitis virus; PV, Pichinde virus; MCMV, murine cytomegalovirus; VV, vaccinia virus.
The numbers above represent the percentage reduction of PFU titer in (A) the spleen or liver or (B) lung.