The WHO on Thursday released details about the three H1N1 (swine flu) virus samples sent to drug makers this week for use in the development of an H1N1 vaccine, AFP/Yahoo! News reports. The vaccine seed viruses – a critical ingredient in vaccine production – were developed in labs in the U.S. and Britain (AFP/Yahoo! News, 5/28). At least one vaccine maker received seed viruses from the CDC earlier this week (Kaiser Global Health Policy Report, 5/28).

During statements last week, WHO interim Assistant Director-General Keiji Fukuda said drug makers should be able to produce an H1N1 vaccine by early July. Earlier this month a team of vaccine makers estimated companies could produce about 4.9 billion doses of a H1N1 vaccine annually (AFP/Yahoo! News, 5/28). WHO Director-General Margaret Chan on Thursday said that WHO could make a recommendation on whether vaccine makers should mass produce an H1N1 vaccine, Xinhua reports (Xinhua, 5/29).

The CDC’s Interim Deputy Director for Science and Public Health Program Anne Schuchat on Thursday said during a telephone briefing that if all goes well with vaccine production and testing over the summer, an H1N1 vaccine may be available by early October – the time that seasonal flu vaccines are typically administered to patients, the AP/Atlanta Journal-Constitution reports (AP/Atlanta Journal-Constitution, 5/28). Reuters reports that clinical trials will help researchers to determine the number of vaccine doses needed to protect against H1N1, if different age groups respond to the vaccines differently and whether an adjuvant, an ingredient that boosts the immune system, would help improve vaccine response, according to Schuchat (Steenhuysen, Reuters, 5/28). 

To produce the maximum quantities of a H1N1 vaccine, a CDC official on Thursday said the U.S. may move to allow the use of currently unapproved adjuvants to improve the effectiveness of the H1N1 vaccine, Reuters reports. Michael Shaw, Associate director of the CDC’s Laboratory Science Influenza Division, said that the use of an adjuvant could potentially “stretch” the H1N1 vaccine, allowing the production of more H1N1 vaccine doses.

“There are a couple of adjuvants that are being looked at now,” Shaw said, adding, “There’s nothing that’s been approved for use in the United States, but there are several that could possibly get emergency use authorization if it appeared it was called for” (Parsons, Reuters, 5/28). The WHO on Friday reported 53 countries have confirmed 15,510 cases of H1N1 infection, including 99 deaths. A full list of country cases and deaths is available here (WHO Influenza A(H1N1) – update 41, 5/29).

Bloomberg reports that a study in the journal Eurosurveillance on Friday reported that two Greek students recently diagnosed with swine flu after traveling to Edinburgh represent “the first confirmation of swine flu in visitors from one European country to another, with no specific history of exposure to a traveler from Mexico or the U.S. and no traceable link to the source of infection” (Gale, Bloomberg, 5/29). China health officials on Thursday said that they believe a 24-year-old who tested positive for the H1N1 virus may represent the first case of local transmission of H1N1, the AP/Wall Street Journal reports (AP/Wall Street Journal, 5/29).

While reemphasizing the WHO’s decision to hold off on declaring the H1N1 virus outbreak to be a pandemic, Chan said Thursday, “The WHO will not compromise global health” in order to appease countries critical of the WHO’s pandemic alert system. “The primary function of the WHO is to respect science, to tell the story like it is,” Chan said, adding, “We are not in phase 6 yet. But we are closer to phase six today than we were last week” (Xinhua, 5/29).