Dr Bronwyn Moore (gyaecologist) answers:
The second injection is administered four weeks after the first injection if your wife has not received the full primary series of tetanus vaccine immunisations- i.e. of three doses in infancy, fourth at four or seven years and the fifth around seven to 12 years of age.
If uncertain, then she needs to receive three doses starting at the first visit- at any time in pregnancy. The second injection is given four weeks after the first and the third injection is given sox months after the second injection. The fourth and fifth injections are administered at one-year intervals, after pregnancy to complete the course.
However, if she has received the full primary vaccination, but has not received the booster within the last 10 s, she then needs to take two injections (at first visit, and second, four weeks later). If she has received the booster within the last 10 years, then she needs to take only one injection.
These days, instead of a plain tetanus toxoid, the World Health Organisation is recommending Td (i.e. tetanus toxoid with low-does of diphtheria vaccine) during pregnancy. The World Health Organisation also recommends that if the woman has received the booster injection within the previous two years, she can then take TdaP (tetanus toxoid,- a low-dose diphtheria vaccine and vaccine against acellular pertussis) soon after delivery.