Bird Flu Surge in China Spurs H7N9 Pandemic Vaccine Preparations

A surge in bird flu cases in China increases the pandemic potential of the H7N9 strain, according to a Beijing-based supplier of influenza vaccines to the Chinese government.

Sinovac Biotech Ltd., the first company to win regulatory approval for a swine flu shot in 2009, is preparing to make immunizations against the new virus that’s infected dozens of people in China and killed 13. The Nasdaq-traded company will hold off producing the shots until it’s received an order from the state, said Chief Executive Officer Yin Weidong.

Flu labs around the world are developing vaccine seed strains to serve as a template for bulk immunization production, should it be required. While there is no evidence that H7N9 is spreading easily among people, it hasn’t been detected in humans before, so they have no natural immunity. That raises global public health concerns, researchers at the Centers for Disease Control and Prevention in Atlanta said last week.

“The risk of this becoming a pandemic is increasing,” Yin said in an interview at the company’s headquarters in the Chinese capital, where a second H7N9 infection was reported today.

Over the past two months, 61 H7N9 cases and 13 deaths have been reported by health authorities, mostly in China’s eastern provinces. About half the infections occurred this month, suggesting the pace of transmission is increasing.

The H5N1 bird flu strain, which killed at least 371 people in Asia and Africa over the past decade, hasn’t acquired the ability to spread easily among people. In 2009, a novel swine flu virus, known as H1N1, touched off the first influenza pandemic in 41 years, showing how diseases of livestock can spill over into human populations, causing a contagion.

Bigger Threat

“This is a much more serious outbreak than H5N1, which from 2003 until now only infected 43 people in China,” Yin said.

Sinovac has notified its suppliers that it may need to order additional fertilized chicken eggs to produce H7N9 vaccine, Yin said. The company doesn’t usually require the eggs in the second half of the year, when the bulk of Sinovac’s seasonal-flu vaccine has been produced, he said.

Under an agreement with China’s Food and Drug Administration, a Sinovac vaccine for pandemic flu doesn’t need to undergo clinical testing because its production methods have already been approved and the pandemic flu vaccine would represent only a change in the viral strain, he said.

Ready in July

Based on typical vaccine development and production schedules, a batch could be ready for commercial use by late July, Yin said, adding that he is urging the World Health Organization and its affiliated labs to expedite the preparation of seed strains.

Sinovac has the capacity to produce about 30 million to 40 million doses of flu vaccine annually, said Yin, who founded the company in 2001 to make immunizations for hepatitis. The price to the Chinese government is about 20 yuan ($3.23) a piece, he added.

The company’s egg-based manufacturing process can supply vaccines with or without an aluminum-based chemical additive, called an adjuvant, which heightens the immune response. It is also able to make vaccines based on either whole or split viruses, Yin said.