Public Health and Epidemiology: Open Access
Community Hybrid Immunity Effect Magnitude in 2024 Versus 2023 on the Risk of Covid-19 Reinfection in a General Medicine Office in Toledo (Spain)
Abstract
Jose Luis Turabian
Background The expression of the true impact or magnitude of preventive measures (vaccination and natural immunity) against covid-19 in daily practice on the population is not yet clear.
Objective To compare the relative risk reduction (RRR), absolute risk reduction (ARR), number needed to treat (NNT), and number needed to harm (NNH) associated with acquired immunity from vaccination and/or infection for SARS-CoV-2 reinfections since 2023 to 2024.
Methodology Comparison of secondary data among covid-19 reinfection cases in 2023 and 2024 years of previous studies. For the calculation of RRR, ARR, NNT and NNH of SARS-CoV-2 infections, cases in 2023 were considered as control group with respect to cases in 2024.
Results The risk of covid-19 reinfection was lower in the group exposed to the immunity level of 2024 versus 2023 in the variables: Men [RRR= 0.4 versus ARR= 0.4], Socio-health workers [RRR= 0.5 versus ARR= 20], and patients with Moderate severe severity [RRR= 1 versus ARR= 0.2]. The greatest magnitude of the effect of the hybrid immunity level was for Socio-health workers (NNT= 5), followed by men (NNT= 250) and patients with Moderate severe severity (NNT= 500).
Conclusion In the context of this general practice setting in Toledo, Spain, the data suggest maintaining vaccination against covid-19 especially in Socio-health workers, and possibly in the entire population or at least in men.