Table 2.

This table shows that the 2 times exposure format in the healed groups lead to significantly higher neutralizing antibody titres than the disease alone. An asymptomatic re-exposure to the virus triggers a high antibody level in the blood. Interestingly, the intranasal PBS before IN virus exposure resulted in less antibody production possibly as result of severe disease. Students t-test p: level of significance, ns: not significant.

Group/Way of Infection IN = Intranasal IOC = Epiocular	G4	G2	G3	G1
G4 Preventive /IOC infection	X	ns	p 0.0013	p 0.0013
G2 Preventive /IN infection		X	p 0.0051	p 0.0025
G3 preventive PBS /IOC			X	ns
G1 Preventive PBS /IN				X