Why Is A Shingles Injection Not Recommended Prior To Knee Surgery?

my husband is scheduled for knee relpacement surgery in 2 weeks. The pharmacist recommends holding off getting the shingles shot until after surgery. My children are bringing there new baby for us to see the first week in August and want us to get the whooping cough shot. Is this safe to do befroe surgery or should we wait until after. If after how long after surgery should we wait.