Whether or not it is possible to prepare for pregnancy after vaccination is decided on a case-by-case basis. With the exception of live viral as well as live bacterial vaccines, all other vaccinations do not affect conception.
Rabies vaccine can usually be used for normal conception about a week after complete vaccination, and Hepatitis B vaccine can be used for pregnancy one month after vaccination.
There are no special contraindications to the flu vaccine, but if a pregnant woman has other primary illnesses such as asthma or heart disease, infection with the flu can aggravate the complications, so it is recommended to get the flu vaccine before the high flu season.
Some vaccines, such as the cervical cancer vaccine and the new coronary vaccine, have limited clinical trial data and there is no guarantee as to whether or not they will have an effect on pregnancy, so it is recommended that you consult your doctor before preparing for pregnancy.