Characterization of SARS-CoV-2 vaccine waning in Mexico

1. We use survival analysis to analyze the decay in the protection induced by eight vaccines using data from 44, 006 patients from the IMSS public health system in Mexico, including only previously vaccinated, confirmed SARS-CoV-2 positive with a PCR test. We analyze three groupings: all data, complete vs. incomplete dose and less than 60 years or older. We found that a Weibull distribution fits very well the complete dose data. Only three vaccines still had 30% of their initial strength after 32 weeks. In two-dose vaccines, we found that the average protection time of a complete dose increases 2 to 3 times compared to that of an incomplete dose.