21. He shall also prepare and keep a duplicate of the register of births required to be kept by him under the provisions of any law for the time being in force, with such additional columns as shall, from time to time, be prescribed by the rules made under section 33, in which he shall record the date of every duplicate certificate in the form of the said Schedule B or Schedule C received by him concerning any child whose birth he has registered, and make an entry to the effect that the child has been vaccinated or is insusceptible of vaccination, as the case may be.