It appears that an individual who is unvaccinated and has recovered from COVID has much greater immunity from his natural defense system than vaccinated individuals. Looks like the CDC in America has given Novak a big leg up.
No wonder why authoritarian governments are petrified of sportsmen who are young fit and healthy like Djokovic and stars in the NFL like Aaron Rodgers who are not following mandates for vaxing and repeated booster programs
FIGURE. Incident laboratory-confirmed COVID-19-associated hospitalizations among immunologic cohorts defined by vaccination and previous diagnosis histories — California, May 30–November 13, 2021*,†
