All police officers and their families and other occupants of Government quarters, or quarters for which rent is paid by Government, shall be vaccinated and re-vaccinated for small-pox at the following intervals :- (a) When there is no epidemic - (i) Infants should, if healthy, be vaccinated in the first three months after birth; in all cases within 12 months. (ii) Children should be re-vaccinated by the time they attain the age of 7 years and again on reaching the age of 16 years. (iii) Adults should be re-vaccinated every seven years. (b) When there is an epidemic. All persons who have not been vaccinated within the last 12 months should be vaccinated. All police officers are enjoined to take the same precautions and they may be called on to do so by executive order.