[High-quality Follow-up Measles and Rubella vaccination Campaign in Mexico, 2021Campanha de vacinação de seguimento de alta qualidade contra sarampo e rubéola no México, 2021].

Objective: To describe Mexico's experience of a high-quality follow-up vaccination campaign against measles and rubella in children aged 1 to 4 years, and actions taken to recover the coverage of other biologics during the COVID-19 health emergency. Method: Use of a microplanning tool in the design and implementation of a follow-up campaign to protect 8 604 781 girls and boys aged 1 to 4 years and to complete other vaccination schedules, followed by the implementation of rapid vaccination monitoring. Results: A total of 8 026 184 doses of MR vaccine were administered to children aged 1 to 4 years, with a coverage rate of 93.3%. In addition, 3 058 201 doses of MMR vaccine and 2 361 021 doses of hexavalent vaccine were administered. Rapid vaccination monitoring was carried out 78 times in selected municipalities in the country, where 30% (18 692) of 62 308 children aged 1-4 years contacted were found to be unvaccinated. The reasons for not vaccinating were "not knowing it was necessary" (28.5%), "not having time" (21.2%), "other reasons" (mainly fear of getting sick from COVID-19 in health centers) (12.9%), "believing they had received two doses of MMR vaccine" (9.1%), or "not knowing where to get vaccinated" (8.7%); 19.6% did not respond. Conclusions: The high-quality vaccination campaign was successful, favoring the sustainability of measles, rubella, and polio elimination, as well as the control of other vaccine-preventable diseases, and demonstrating the relevance of microplanning.