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A physician for Novak Djokovic attested that because the Serbian tennis star had caught and recovered from COVID-19, he was eligible to apply for a medical exemption to not get the COVID-19 vaccine. 

Catching and recovering from the virus offers some natural protection against further infection -- but natural immunity differs from person to person and wanes over time. As tens of thousands of Australians become infected daily, the question remains: should there be different rules for the recovered? 

What level of natural immunity is there?

When it first emerged, there was considerable speculation about whether COVID could be caught twice. Reinfections were initially rare -- by August 2020 just a handful of people who had caught the virus became reinfected.