Here is a list of biotech companies whose shares may rise or fall depending on the course of the swine flu pandemic.
GILEAD SCIENCES INC - Receives royalties on sales of the Tamiflu pill, which Roche Holding AG sells under license from Gilead. According to analysts at Barclays Capital, current projections for the second half of the year suggest combined seasonal and pandemic Tamiflu sales of $1 billion.
BIOTA HOLDINGS LTD - The Australian biotech company receives royalties on sales of the inhaled antiviral drug Relenza, which is marketed by GlaxoSmithKline Plc. Biota's royalties more than doubled to $37.5 million in the year to June. The company is developing a new flu drug, laninamivir, with Daiichi Sankyo. Late stage studies in Asia showed a single dose of inhaled laninamivir alleviated flu as effectively as five days of twice-daily Tamiflu.
* NOVAVAX INC - Will apply to U.S. Food and Drug Administration in the fourth quarter to start human clinical trials of its H1N1 vaccine. An earlier trial of the virus-like particle (VLP) vaccine showed it protected ferrets from swine flu. The vaccines can be grown in caterpillar cells and can be produced much quicker than traditional vaccines made using chicken eggs.
* BIOCRYST PHARMACEUTICALS INC - Has intravenous antiviral called peramivir in late stage development. A late-stage trial sponsored by partner Shionogi & Co Ltd of Japan showed peramivir was no less effective than Tamiflu.
* VICAL INC - Developing a gene-based vaccine using its Vaxfectin adjuvant, which boosts the immune system. Early trials showed it produced a robust immune responses in animals. The company is developing vaccines against the H5N1 avian flu strain and the new H1N1 virus.
* INOVIO BIOMEDICAL CORP - Developing DNA-based H1N1 flu vaccines that protect pigs and mice. It will jointly develop universal influenza vaccines -- vaccines that target several strains of the virus -- with the National Institutes of Health's research unit.
* MEDICAGO INC - The Canadian biotech makes protein-based vaccines through the genetic engineering of plants such as tobacco. It is working to form agreements in different geographies. Most recently, it said it expects to sign a licensing agreement with a Middle East company that will pave the way for the say for the development of its swine flu vaccine in the region.
* GENEREX BIOTECHNOLOGY CORP - Making synthetic peptide vaccines. These differ from egg-based vaccines in that they do not use a live virus. Instead, peptides are arranged so as to mimic the virus, priming the immune system. The vaccines are designed to be produced more quickly than traditional vaccines. Generex will apply to U.S. regulators in the fourth-quarter to start human trials.
* CRUCELL NV - The Dutch biotech plans to begin clinical trials of its experimental antibody-based flu drug mAB CR6261 next year. The company's PER.C6 technology uses human cells rather than chicken eggs to produce an antibody to prevent a infection with a variety of flu viruses.
* CSL Ltd - Australia's CSL has completed its first batch of 2 million shots in 15 microgram doses and is producing up to 1.5 million doses per week until it fills orders, which include an order for 21 million doses from the Australian government and $180 million in orders from the United States.
* GREEN CROSS - Green Cross, the only South Korean drug company that can mass produce an H1N1 flu vaccine, has signed a $7.4 million supply deal with the government, which secured 1.1 million doses of the vaccine for delivery by the end of November.
SINOVAC BIOTECH LTD - The China-based company is the first worldwide to complete clinical trials of an H1N1 flu vaccine. It said the vaccine, which is given in a single dose, rather than the two doses typical for a vaccine, is ready for delivery. Sinovac expects to produce 30 million doses.
HUALAN BIOLOGICAL - A Chinese panel of experts has given the green light to the Shanghai-listed company's vaccine. It is expected to be approved there this month.
(Reporting by Toni Clarke; Editing by Maggie Fox, Gary Hill)