People aged 25 or older who are considered at high risk for complications from influenza A (H1N1) will be offered H1N1 vaccine free of charge from Monday, the Centers for Disease Control (CDC) announced Sunday. People in the age groups with underlying health conditions that include diabetes, asthma, chronic cardiopulmonary disease, kidney disease, liver disease, cardiopulmonary disease and severe obesity should get vaccinated as soon as possible, CDC Deputy-Director Chou Jih-haw said. Severe obesity is defined as a body mass index (BMI) of greater than 35 kg/m2, according to Chou. He noted that individuals with hypertension have not been listed in the high risk group so they will be given the vaccine only until Dec. 12, when the vaccine will become available to the general public. More than 2.51 million people have been inoculated against H1N1 since the CDC began offering the vaccine nearly one month ago, of whom, 1.17 million are students at junior and senior high schools. However, only 5,000 university students have received a shot, Chou said. The CDC plans to get 7.5 million people vaccinated by the end of this year -- about 25 percent of the population -- in order to generate a herd immunity effect, according to Chou. 