A main thrust of these initiatives is to spur research and development (R&D) on new vaccines to prevent infections that kill millions of people every year. The PATH Malaria Vaccine Initiative is launching Phase 3 trials for a promising malaria vaccine developed by GlaxoSmithKline (GSK), and the Aeras Global TB Vaccine Foundation has several candidates in early clinical trials. Rotavirus vaccines recently received a strong push from the World Health Organization's decision to add this preventive to national immunization programs for infants and children.Vaccine development is strong at home as well, as new preventives for human papillomavirus, rotavirus, and shingles have hit the market. The US Food and Drug Administration approved three vaccines last year, and several important applications are in the queue. Meanwhile, the agency has its hands full reviewing filings for the new pandemic H1N1 vaccine, now being tested and produced as fast as possible. The US expects to spend some $8 billion for nearly 200 million doses of the flu vaccine from GSK, Novartis, Sanofi Pasteur, Astra-Zeneca's MedImmune, and Australia-based CSL Limited. European and other nations have placed comparable orders.
The FDA and the industry face several challenges in meeting the demand for H1N1 vaccines, as discussed at a July meeting of FDA's Vaccines and Related Biological Products Advisory Committee. The agency is allowing licensed manufacturers to file manufacturing supplements for a strain change, similar to what companies do each year for new seasonal flu vaccines. Because the H1N1 vaccine is a slightly different single-strain vaccine, companies have to conduct clinical trials to ensure safety, determine the necessary dose strength for effectiveness, and decide whether one or two doses are needed. Another question is whether the swine flu vaccine should be administered separately or with a seasonal flu shot.
The National Institutes of Health is conducting additional clinical trials to test dosing options for various age groups and the need to mix the new vaccine with an adjuvant to achieve the desired immune response. If an adjuvant is needed, the FDA plans to use its emergency authority to expedite access to what would then be a new vaccine. The agency took this route earlier in the year to permit treatment of infants with antivirals not yet labeled for that age group, but has not used this approach for a new vaccine.
Even if all the testing comes out well, it's not clear how quickly the industry will produce the millions of needed doses. Companies experienced difficulties cultivating antigen from the available H1N1 strains, but yields began to rise last month, generating hopes for initial supplies in September. MedImmune reported great success in producing bulk quantities of its FluMist vaccine, which is made from a live virus, but doesn't have enough nasal spray devices to deliver the inhaled product.
MedImmune's excess supply, though, may lead to overseas sales, as vaccine makers capitalize on the opportunity created by the flu pandemic to expand production and distribution. Sanofi gained FDA approval for its new Swiftwater, PA, vaccine manufacturing facility earlier this year, while foreign manufacturers, such as Sinovac Biotech in China, have geared up to conduct clinical trials and expand production of a influenza vaccine at home. Struggling Connecticut-based Protein Sciences Corporation has received federal funding to develop new flu vaccine development methods, leading to testing for its experimental PanBlok vaccine. Inovio Biomedical of San Diego has gained attention from positive animal studies on its DNA-based flu vaccine, although it will take several years to bring such a product to market.
The demand for a pandemic flu vaccine also has spurred development of novel antigens and testing standards. Earlier this year, FDA scientists unveiled a new antigenic fingerprinting approach for testing the potential protective activity of vaccines under development. Vaccine makers are moving forward with the development of a cell-based manufacturing technology for influenza vaccine, the long-desired approach for accelerating seasonal flu vaccine production.