1. Influenza (Flu) vaccine
Benefits:
Flu is more likely to cause severe illness (including lung infection) in pregnant women (especially those who are overweight) than in non-pregnant women. Viral influenza vaccination was associated with 50% reduction in confirmed influenza among women and their babies. There was, however, no clear difference between vaccinated and non-vaccinated women in miscarriage, premature labour, stillbirth, admission to hospital for infection for baby or mother.
Risks:
Common side effects include pain and redness, swelling, headache, fever, nausea, muscle aches, fainting.
Rare side effects includes generalized weakness or tingling sensations over the limbs and upper body. Studies have shown a risk of 1-2 of such cases per million people vaccinated.
Schedule:
It is recommended by authorities in many developed countries. This involves one dose of inactivated vaccine any time in pregnancy (consider doing so after 12 weeks). But it is not recommended if you have a history of nerve disorders and probably not a good idea during periods of active Zika transmission as the side-effects of the flu vaccine may mask the symptoms of Zika infection in the mother.
2. Pertussis vaccine
Benefits:
Protects the newborn baby between 0-6 months against whooping cough (pertussis) and tetanus. There has been a surge in whooping cough infections in newborn babies in recent years, and may result in admission to intensive care units in some of them. The immunity you get from the vaccine will pass to your baby through the placenta and provide protection for them until they are old enough to be vaccinated against whooping cough at 6 months old. Currently there isn't a single vaccine against whooping cough alone, so we use a combined vaccine (Tdap).
Risks:
Minor side effects include pain and redness, swelling, headache, tiredness, nausea and vomiting, fever, sore joints, body aches.
Rare side effects include rash, swollen glands, severe allergic reaction estimated in 1:1,000,000 and will happen within a few minutes to a few hours after vaccination, and difficulty moving arm after vaccination.
Schedule:
It is recommended by authorities in many developed countries to be given at 16-32 weeks regardless of prior status. The pertussis-only vaccine is sufficient for this purpose.
For patients going to deliver in countries where neonatal tetanus is still endemic (e.g. India), tetanus toxoid vaccinations for all pregnant women is recommended. The Tdap vaccine (which covers for tetanus, diphtheria and pertussis) replaces the need for an additional tetanus toxoid in such patients. This is not necessary in many developed countries e.g. Singapore as neonatal tetanus is no longer seen.