In the Mexican context, after 17 months of online classes due to the COVID-19 pandemic lockdown, educational and health authorities established measures to guide the return to in-person classes under a health protocol, considering primary and secondary schools across the country to prevent the spread of SARS-CoV-2. We aimed to analyze how the return to classes was conducted in adherence to the guidelines established by the authorities at a telesecundaria (remote learning secondary school). We sought to recognize the practices, customs, and traditions of how the sanitary measures were internalized within the telesecundaria community, considering students, teachers, and parents. The objective was to understand whether the implementation of sanitary measures was due to hygiene and prevention habits learned during the lockdown, if the measures were implemented as an institutional practice demanded by an authority figure, or if the customary ways of interaction were resumed within the school community, bypassing the use of sanitary measures. For the analysis, we relied on the Theory of Social Representations and the adaptation of the 3Cs model of vaccine hesitancy. The work was based on a non-probabilistic longitudinal case study. For data collection, we used mixed methods and techniques such as surveys, interviews, and observation, applied between May and October 2022, covering two academic years. We found that after the immunization of students with vaccines, the use of sanitary measures in the educational institution decreased.