@dredmorbius @isagalaev @kravietz you are estimating that based on what exactly? several studies show robust post-infection immunity for >6 months, e.g.

The study estimated the efficacy of natural infection against reinfection at 95.2% by comparing SARS-CoV-2 incidence in those antibody-positive to those antibody-negative... Remarkably, this efficacy estimate is similar to the efficacy reported for the two mRNA COVID-19 vaccines

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(21)00141-3/fulltext