The Science Behind Developing the H1N1 Vaccine

April 21, 2010

By Tony Fauci, NIH

When a new strain of H1N1 influenza virus was recognized last April, the National Institute of Allergy and Infectious Diseases (NIAID)—part of the National Institutes of Health (NIH)—responded swiftly to the scientific challenges it presented. Indeed, for the past several years, NIAID has worked closely with our sister agencies in HHS and other partners in government, academia, and industry to enhance our nation’s preparedness for pandemic as well as seasonal influenza.

Once the 2009 H1N1 influenza virus was identified, scientists at NIH, CDC, and FDA laboratories, as well as scientists at medical centers funded by NIH grants, quickly received samples of the virus to begin characterizing the novel virus thoroughly in cell culture and laboratory animals, analyzing its structure, and conducting genomic sequencing.  Those efforts involved close coordination with industry and academic partners, including the NIAID-supported Centers of Excellence in Influenza Research and Surveillance (CEIRS) and the Regional Centers of Excellence for Biodefense and Emerging Infectious Diseases (RCEs). 

A candidate virus strain was rapidly identified that would provide the foundation for a vaccine to protect people against the virus. As industry partners began producing pilot lots of 2009 H1N1 vaccines, NIH was readying its longstanding vaccine clinical trials infrastructure—the Vaccine and Treatment Evaluation Units, located at medical centers across the country—to conduct a series of clinical trials to evaluate the vaccines. Close collaboration among NIH, FDA, and the HHS Office of the Biomedical Advanced Research and Development Authority enabled these studies to launch quickly while ensuring the highest ethical and scientific standards. The trials, which enrolled thousands of volunteers, assessed the safety of the vaccines and their ability to induce an immune response that would be predictive of protection.  Data from these studies helped public health leaders develop recommendations for immunization schedules, including the optimal dosage and number of doses for people ranging in age from young children to the elderly, and for specific populations, such as pregnant women. 

NIH-supported research continues to provide critical information concerning the mechanisms by which influenza viruses cause disease, as well as factors that influence the degree of virulence and transmissibility of influenza viruses. Ongoing research will provide further insights that will help us develop new strategies for diagnosing, treating and preventing seasonal and pandemic influenza in the future.