Final answer:
During the prenatal visit at 30 weeks gestation, the vaccine that can be safely administered to a pregnant client is the influenza vaccine. Therefore, the correct option is 1.
Step-by-step explanation:
The influenza vaccine is the one that can be safely given to a pregnant client during the prenatal checkup at 30 weeks gestation. It is advised that the mother receive this vaccination to protect the foetus from the flu, which can be quite dangerous during pregnancy.
The other vaccinations, which include varicella, measles, mumps, and rubella (MMR), and tetanus, diphtheria, and acellular pertussis (Tdap), are often not given to pregnant women. To maximize the newborn's protection against pertussis, tdap is usually administered between 27 and 36 weeks during the third trimester.
Due to the potential harm to the developing foetus, live attenuated vaccinations such as the varicella and MMR are typically not recommended during pregnancy. For tailored advice based on unique health situations, always seek the advice of healthcare specialists.
Therefore, the correct option is 1.