1607-050X 1607-050X S1607-050X2021000100180 México 00 04 2021 00 04 2021 65 180 187 1958 2020 84 84 2020 1992 Centers for Disease Control and Prevention (CDC) 2020 1990 1994 11 1 1 4-12 2006 2014 1972 2011 369 ١٩٣٨ ١٩٣٨ 842-67 2009 2002