Before revision:  Through Twitter 's standard search application programming interface , we retrieved over 63 million coronavirus-related public posts from more than 13 million unique users since 28 January to 1 July 2020.
After revision:  Through Twitter 's standard search application programming interface , we retrieved over 63 million coronavirus-related public posts from more than 20 million unique users since 28 January to 1 July 2020.