A woman gets a voluntary swine flu vaccination from a nurse at a subway station in Mexico City, Tuesday Jan. 31, 2012. Federal Health Secretary Salomon Chertorivski Woldenberg said Tuesday there have been 1,623 cases of all strains of flu in Mexico so far in January, 90 percent of them H1N1. Despite the spike, Chertorivski said the cases are within normal range for a flu season.