Which of the following activities should only be performed by a pharmacist?

The activity that should only be performed by a pharmacist is deciding whether a patient needs a vaccine. This decision is based on a comprehensive evaluation of the patient's health status, medical history, potential contraindications, and the current guidelines for vaccination. Pharmacists possess the necessary training and clinical knowledge to assess these factors and make informed decisions regarding patient vaccinations.

The other activities mentioned, while important, may often involve support staff or other healthcare professionals. Documenting the vaccine can be performed by trained pharmacy technicians or administrative staff as long as they are following the proper protocols. Communicating information about the vaccination to a patient's primary care provider can also be carried out by other healthcare professionals, provided they have the requisite information and authority to do so. Gathering information about a patient's vaccination history may be conducted by technicians or other healthcare providers during patient intake processes, again as long as it aligns with regulatory standards and training. Thus, each of those tasks can involve roles beyond the pharmacist, but the decision-making regarding vaccine necessity is strictly within the pharmacist's scope of practice.