Interference between the viruses of tick-borne encephalitis complex in the Ixodes ricinus ticks.

The interference of two closely related viruses of the tick-borne encephalitis complex (TBE) in Ixodes ricinus ticks has been observed. 42.9 to 65.0% of dually infested ticks developed virus neutralization antibodies in mice without signs of illness, which contrasts with the control ticks infected with 198 strain only. Other explanations of this interference could include alteration of viral receptors on host cells or induction of antiviral activity in the infected ticks and/or other vectors such as mosquitoes.