Little to no studies done on pregnant women and vaccines.

“Pharmaceutical companies, which are the main sponsors of clinical trials overall, could face serious financial repercussions if a vaccine study was correlated with a serious adverse effect/event like miscarriages or congenital malformations. The result is that most developers protect themselves against liability leaving the decision about the administration of a vaccine or drug to the treating physician. This leads pregnant women and their physicians to blindly navigate the decision-making process”