The nurse is caring for a pregnant client during the first prenatal visit. Prior to obtaining prenatal lab work the client asks the nurse, "Why do I need a rubella screening? I was already vaccinated.”. What explanation by the nurse is most accurate?

Screening determines if the client is a candidate for rubella immunization during pregnancy.

Screening will determine the risk of teratogenic effects to the fetus from prior vaccination.

Screening will determine if the client is a carrier of the rubella virus from previous exposure.

Screening determines adequate immunity to protect the client and fetus from the virus.