Doris Bucher at New York Medical College , in Valhalla , New York . Bucher told CNN Thursday that she had just packaged four viruses that she considers vaccine candidates and sent the samples to the CDC 's headquarters in Atlanta , Georgia , via courier . Earlier this week , a Korean scientist , Dr. Seo Sang-heui , also claimed to have produced a virus that might be used in a swine flu vaccine . But Skinner said the methods Sang-heui used were not suitable and that his virus was not considered a viable candidate . Bucher 's samples will likely get more attention . For the past five years her lab in Valhalla has produced elements of the seasonal vaccine that 's given to tens of millions of Americans each year . She says the process she 's using with the H1N1 virus is virtually identical to the process her lab uses when working on that seasonal vaccine . The virus used in vaccines is not the actual virus that infects people , but rather a hybrid that 's been genetically modified to make it safer , and to give it the ability to multiply more quickly --
-LRB- CNN -RRB- -- The Centers for Disease Control and Prevention received a candidate vaccine virus for swine flu from one institution Friday , spokesman Thomas Skinner said in an e-mail . The CDC estimates more than 100,000 people have had swine flu in the United States . The CDC and the U.S. Food and Drug Administration have also created a candidate vaccine virus for swine flu , also known as 2009 H1N1 , using reverse genetics , he said . `` Suitable viruses will hopefully be sent to manufacturers by end of next week , '' Skinner wrote . Once that happens , vaccine makers will tweak the virus and have `` pilot lots '' of vaccine ready to be tested by mid - to late June . Several thousand cases have been reported nationally , but the CDC estimates more than 100,000 people have had swine flu in the United States , said Dr. Anne Schuchat , interim deputy director for science and public health program at the CDC , in a news conference Friday . Most of these people probably have not been officially tested . The first sample virus came from a lab run by virologist