I know what is immunisation schedule is but the question is how do they set the schedule...?

Question

what i meant by how they set it is actually why BCG is given as the first vaccine upon birth and not the OPV or DPT, why do they have a certain combination like in the third month upon birth the baby is given the combination of the DPT and OPV but when comes to BCG only one vaccine is involved, why do they have such duration 3rd,4rd and fifth month? kindly help me out with this. Thank u in advance

Answer 1

There is no point in giving the immunization before the child's body is ready to process it. So, for some kinds of immunizations, you must wait until the child's body reaches a certain stage of maturity.
The length of time required to reach full immunization may vary.

Some immunizations work very well with only one exposure, and other require that the immunization be repeated to be sure that the child develops immunity.

Very young infants have immunity from their mother and they may have immunity longer if they are being breast fed. So, you can't immunize them if they already have immunity. But when they stop being breast fed then they will lose the immunity from the mother and have to develop their own immunity. So the immunization has to be timed to match the end of breast feeding.

The public health doctors have to take all these and other factors into consideration in deciding when to schedule the immunizations.