By September, the first H1N1 (swine) flu vaccines will be approved and ready for use, WHO director of the Initiative for Vaccine Research Marie-Paule Kieny said Thursday, Reuters reports. Kieny also expressed optimism that “vaccine production yields were improving, following a disappointing start that triggered some worries about supplies,” the news service writes.

By early next month, Kieny said scientists will have the results of the first H1N1 vaccine clinical trials, which aim to determine “how many doses of the new vaccine will be required to provide sufficient protection against the virus,” the Los Angeles Times’ blog “Booster Shots” reports. “Preliminary studies have suggested that the antigen being used does not provoke as strong a response as that in the seasonal flu vaccine, and that it may be necessary to use two doses — which would halve the total number of people who could be immunized” (Maugh, 8/6).

Reuters reports that “[o]nce initial clinical trial results are in, regulators will be able to approve the vaccines from next month and the first countries are expected to start mass vaccination programmes, Kieny added” (Lynn/Hirschler, 8/6).

Obama Will Discuss H1N1 With Mexican President, Canadian Prime Minister

In related news, President Obama is scheduled to meet with Mexican President Felipe Calderon and Canadian Prime Minister Stephen Harper in Guadalajara, Mexico, Sunday and Monday to discuss ways to deal with the anticipated resurgence of H1N1 this fall, Reuters reports in a separate story. The leaders are expected to issue a joint statement about their collaborative efforts to limit the severity of H1N1, White House Deputy National Security Adviser John Brennan said.

“I think everybody recognizes that H1N1 is going to be a challenge for all of us and there are people who are going to get sick in the fall and die. People have been dying over the past number of months from H1N1,” Brennan said (Holland, 8/6).