Babies in the UK can't start their vaccines until eight weeks old, Dowager.
The vaccine is primarily for the baby's benefit, though of course there is some benefit to the mother too.
So much misinformation on this thread, no wonder pregnant women are confused. Please speak to your practice nurse who will be administering this vaccine if you have any questions and concerns.
It is not a live vaccine.
It cannot be given before 28 weeks.
It also contains diphtheria, tetanus and polio.
It is the "same" vaccine given to preschoolers. (Not literally but has the same components).
Vaccines have changed since we were children, and the whooping cough (pertussis) vaccine used now is completely different to the vaccine used in the 70s and 80s.
It is not compulsory, but has reduced the numbers of infant deaths from pertussis to virtually nil. It has been a very effective immunisation campaign hence why it is to continue for the foreseeable future.