Chinese health authorities have given approval to a domestic company to mass produce a vaccine for the H1N1 strain of flu. Unlike other vaccines, this one does not require multiple doses.
The Chinese bio-technology company Sinovac says its H1N1 vaccine only requires one shot to be effective. This defies previous expectations that vaccines against the so-called swine flu would need two doses to work.
Wang Nan, vice-general manager at Sinovac, says the company began research on the vaccine in early June.
Wang says 21 days after giving subjects the first injections, experimenters tested their blood and discovered that one dose provided the expected level of protection.
Wang says Sinovac will focus on China's market first, but is also interested in selling the vaccine internationally. Sinovac can produce 30 million doses of the vaccine a year.
The Chinese government plans to vaccinate 65 million people against H1N1 this year. The World Health Organization says countries in the northern hemisphere already have ordered more than one billion doses of swine flu vaccine.
Vivian Tan, the spokeswoman for the WHO in China, says the main benefit of a one-dose vaccine is that it is possible to vaccinate twice as many people. But she says the approval of the Sinovac vaccine does not mean supplies will be sufficient.
"Generally in the initial months there will not be enough vaccine produced for the world, that's for sure, because the global production capacity of vaccines just cannot meet the need as we stand today," Tan said. "That's why it's really important for countries to prioritize the groups that should receive the vaccine first."
Tan says the WHO suggests health care workers should be among the first vaccinated, because they are on the front-line of fighting the virus. Other priority groups include people with underlying chronic conditions like diabetes, asthma or cardiovascular problems. Pregnant women also seem to be more vulnerable to H1N1.
China's State Food and Drug Administration says trials of Sinovac's vaccine shows it is "very safe." The regulatory agency is expected to decide by mid-September whether to approve applications from nine other companies developing H1N1 vaccines.
China is a global manufacturing center for pharmaceuticals, but there have been cases when companies substituted cheaper or even lethal ingredients. Tan says as long as proper procedures are followed to ensure the safety and efficacy of Sinovac's vaccine there should be no reason to worry.
"That said, I think it's very important to continue to monitor the situation once mass vaccination starts because so far the vaccine has only been tested in small groups and clinical trials," she said.
Tan says there are over 3,000 cases of H1N1 in China but no fatalities, so she thinks health authorities are handling the situation well.
This strain of flu has appeared in almost every country since being identified earlier this year. The WHO estimates 2,185 people have died of the virus.