Serological testing is not required to confirm a history of chickenpox before receiving Shingrix, regardless of age or medical condition.

For persons who are unsure if they have had chickenpox before, they can discuss with their doctor on the need for a serology (blood) test. If they are found to be non-immune to varicella, the chickenpox vaccine should be given instead of Shingrix. Although Shingrix is also safe for those who have never had chickenpox before, it does not protect against chickenpox infection.