Effect of vibration associated with cryotherapy on vaccine-related pain and anxiety levels in adults: study protocol for a randomized clinical trial

Abstract
Vaccination is one of the most effective strategies for prevention and eradication of immunopreventable diseases, but community acceptance of vaccination can be influenced by different factors, such as pain and anxiety. The use of high-frequency vibration associated with cryotherapy has been used to manage pain and anxiety during the vaccination process in children, but studies with adults are still scarce. This study aims to evaluate the effect of high-frequency vibration associated with cryotherapy on the levels of self-reported pain and anxiety related to administration of the Influenza vaccine intramuscularly in adults. A two-arm, parallel, randomized clinical trial conducted in a Brazilian Primary Health Care Unit is proposed. A sample of 350 adults will be randomly assigned to participate in the control group, receiving the vaccine intramuscularly according to the standard protocol of the service, or in the intervention group, receiving the vaccine by the same route and using a portable device of high frequency vibration associated with cryotherapy for 30 s before and during administration. The primary endpoints will be self-reported levels of pain, assessed before and after vaccine administration. Secondary endpoints will be levels of anxiety, satisfaction with vaccine administration, and discomfort caused by high frequency vibration and temperature of the frozen bag in contact with the skin. Self-reported levels of pain and anxiety will be compared before and after vaccination as well as between the control and intervention groups. By evaluating the effect of high-frequency vibration associated with cryotherapy on pain and anxiety levels, we expect to find evidence that will support nursing practice, in order to promote greater comfort and safety in the vaccination process and, consequently, greater compliance by the population, by minimizing its undesirable effects. Human Research Ethics Committee Opinion Number: 5.138.564. Approved on December 2, 2021. Brazilian Registry of Clinical Trials (REBEC): Registration number RBR-5zgy25w. Registered on December 09, 2021.