Brazil’s Sao Paulo state delayed on Monday the release of efficacy data for the COVID-19 vaccine developed by China’s Sinovac, tightening the timeframe for regulator approval before a planned roll out on Jan. 25, reported Reuters.

Governor Joao Doria said in a radio interview on Monday the data would be released on Dec. 23, eight days later than planned, to allow for a larger sample size and more complete analysis.