( CNN ) -- In a race to beat the flu season , medical institutes across the United States will begin human trials for a new H1N1 flu vaccine starting in early August , the National Institutes of Health announced Wednesday . Concern about the H1N1 virus grew after it spread quickly around the globe earlier this year . In the hope of getting the vaccine to those who will need it most by October , the clinical trials will enroll as many as 1,000 adults and children at 10 centers nationwide , said officials at the National Institute of Allergy and Infectious Diseases , a division of the NIH , which will lead the effort . The trials will measure the safety and effectiveness of the vaccine . The research is a first step toward U.S. health officials ' goal of developing a safe and effective vaccine against H1N1 , also known as swine flu , which has been declared a global pandemic by the World Health Organization . The time frame for developing a vaccine is a tight one . `` It 's going to be close , '' said Dr. Anthony Fauci , director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health . `` I believe it can be [ ready by October ] if things run smoothly . We hope they will , but you never can tell when you 're dealing with biological phenomena like making vaccines and administering them . '' The announcement of the U.S. trials followed the announcement earlier this week , by an Australian company , CSL Ltd. , of the first human trials of a swine flu vaccine . Concern about the H1N1 virus grew after it spread quickly around the globe earlier this year . `` This virus has the potential to cause significant illness with hospitalizations and deaths during the U.S. flu season this fall and winter , '' said Dr. Karen Kotloff , professor of pediatrics and lead investigator and researcher at Maryland 's Center for Vaccine Development . `` Vaccines have always been a vital tool for controlling influenza . The results of these studies will help to guide the optimal use of the H1N1 vaccines in the U.S. and elsewhere in the world . '' After careful screening , volunteers will be inoculated and then asked to keep a diary on how they feel . After eight days their blood will be checked and after 21 days they will receive another dose , followed again by diary logs and blood tests . Patients will be monitored two months for safety issues , followed by a four-month and six-month checkup . `` The purpose of these trials is always to make sure they are safe , '' Kotloff said . `` But even after six weeks , if things look good , we 're pretty sure the vaccine will work . '' She noted the response to the vaccine may vary in different age groups . `` This is because young people have not seen a flu virus like this one before , '' she noted . `` Older adults might have some immunity to the new H1N1 virus as a result of being exposed to similar flu viruses in the past . As a result , older adults might need fewer doses or a lower strength of the vaccine than younger individuals . '' The vaccine at this point has been tested only in animals , where it has shown to be effective . Further trials will examine questions such as how the vaccine works in combination with the seasonal flu vaccine and whether including an adjutant , a substance that boosts the immune response to vaccines , can make it work better at lower doses . Other trial sites along with the University of Maryland Medical Center are Baylor College of Medicine , Cincinnati Children 's Hospital Medical Center , Emory University , Saint Louis University , Seattle Group Health Cooperative , the University of Iowa , and Vanderbilt University . They will be joined by Children 's Mercy Hospital and Duke University Medical Center . CNN 's Valerie Willingham and Matt Cherry contributed to this report .
Human trials for H1N1 flu will start August , says University of Michigan . Concern about vaccine grew after it spread around the world earlier this year . Patients will be monitored two months for safety issues , followed by checkups . Vaccine so far tested only in animals , where it has proven to be effective .