Which is TRUE regarding polio?

Most of the Polio infections (95%) are asymptomatic. Paralysis occurs in only 0.01% cases of all poliovirus infections. The risk factors found to precipitate an attack of paralytic polio in individuals already infected with polio include, fatigue, trauma, IM injections, operative procedures like tonsillectomy undeaken especially during epidemics of polio and administration of immunizing agents. Pulse polio immunization is given to all children less than 5 years of age and not 3 years of age. Ref: O.P. Ghai 6Th Ed Page 210-212.