Pfizer Inc.: U.S. FDA Accepts for Priority Review Pfizer's Application for TicoVac (Tick-borne Encephalitis Vaccine) 4 transmitted to humans through the bite of an infected tick, 5 and less frequently by ingestion of unpasteurized milk or milk products from infected animals. 4 It may initially be mistaken for summer flu, 18,19 but can be a serious condition with possible long-term consequences. 4,19 More than 1 in 3 people can have long-term effects that last months or years including cognitive changes, muscle weakness or permanent paralysis, 4,19 and in rare cases (0.5-2%; up to 20% in Russia), people may die. 20,21 TBE can affect people of all ages who come into contact with ticks whenever they do outdoor activities in countries where ticks infected with TBE are prevalent.