SEATTLE: Microsoft co-founder Bill Gates said on Tuesday (Wednesday in Manila) that he had tested positive for Covid-19 and was experiencing mild symptoms. On Twitter, the billionaire philanthropist wrote he would isolate himself until he was healthy again. 'I'm fortunate to be vaccinated and boosted and have access to testing and great medical care,' Gates added. The Seattle-based Bill and Melinda Gates Foundation is the most influential private foundation in the world, with an endowment of about $65 billion. Bill has been a vocal proponent of pandemic-mitigation measures, specifically access to vaccines and medication for poorer countries. The Gates Foundation said in October it would spend $120 million to boost access to generic versions of drugmaker Merck's antiviral Covid-19 pill for lower-income countries.