 In 2011 , a study from the US Flu Vaccine Effectiveness Network estimated the overall effectiveness of all pandemic H1N1 vaccines at 56 % . A CDC study released 28 Jan 2013 , estimated that the Pandemic H1N1 vaccine saved roughly 300 lives and prevented about 1 million illnesses in the US . The study concluded that had the vaccination program started 2 weeks earlier , close to 60 % more cases could have been prevented . The study was based on an effectiveness in preventing cases , hospitalizations , and deaths of 62 % for all subgroups except people over 65 , for whom the effectiveness was estimated at 43 % . The effectiveness was based on European and Asian studies and expert opinion . [ 3 ] The delay in vaccine administration demonstrated the shortcomings of the world 's capacity for vaccine @-@ production , as well as problems with international distribution . Some manufacturers and wealthy countries had concerns regarding liability and regulations , as well as the logistics of transporting , storing , and administering vaccines to be donated to poorer countries . 
