Even as the rate of new 2009-H1N1 infections steadied in the Northern Hemisphere, the World Heath Organization on June 11 declared a pandemic. Now heath authorities are bracing for the influenza's re-emergence in the United States this fall. David Obey (D-Wis.), chair of the House Appropriations Committee, has called for $2.05 billion in supplemental funding to increase surveillance of outbreaks and to purchase medications. Efforts are under way to develop a vaccine for 2009-H1N1. “We're taking those initial steps that are important and necessary should a vaccine [for 2009-H1N1] need to be made,” said Richard E. Besser, MD, director of emergency response and past acting director of the U.S. Centers for Disease Control and Prevention. “There are a lot of decisions that need to be made” by this fall, when people start receiving their flu shots. Current gaps in knowledge about 2009-H1N1 are expected to be filled in the coming months as the flu season unfolds in the Southern Hemisphere. During this time, he said, epidemiologists will be seeking answers to several questions: How does the virus compete with other viruses that are circulating in the community? Does it develop resistance? The earliest a 2009-H1N1 vaccine will be available is in September, according to Klaus Stöhr, DVM, vice president and global head of Novartis Vaccines and Diagnostics Ltd. and former head of the WHO's Global Influenza Program. Dr. Stöhr spoke at the international conference on Influenza Vaccines for the World held in Cannes, France. The number of inoculations necessary will depend on how potent the vaccine needs to be, explained William Schaffner, MD, chair of the department of preventive medicine at Vanderbilt University, Nashville, Tenn. In all likelihood, the 2009-H1N1 vaccine will require two shots to ensure immunity. Couple that with the logistics of providing the seasonal influenza vaccine and “the potential for confusion is vast,” he said in an interview. A lot could happen between now and the fall. “We could see the current strain fizzle out and never come back again. We could see the current strain come back as it currently is, or we could see it mutate and come back in a more severe form. What we need to do during this period is make sure that we're prepared as a government, as a public health agency, [and] that our laboratories are ready should this come back as a much more severe infection,” Dr. Besser said at a CDC press briefing. In the meantime, long-term care facilities should follow infection control procedures to reduce the spread of viral organisms, said AMDA Director of Clinical Affairs Jacqueline Vance, RNC, CDONA/LTC. “This includes stressing hand washing for staff and visitors alike and putting policies in place to restrict entering the facility if anyone—staff and visitors alike—has any signs or symptoms of the flu,” she said. So far, the genetic analysis of 2009-H1N1 has shown no sign of the virulence markers found in the 1918 pandemic influenza strain, also an H1N1 type, said Nancy Cox, PhD, chief of the influenza division at the CDC. She echoed the caution, however, that a great deal about 2009-H1N1 is still unknown. The 2009-H1N1 strain is “easily transmitted,” with an attack rate of about 25%-30%, based on early analyses of person-to-person spread within families and households, said Anne Schuchat, MD, director of the CDC's National Center for Immunization and Respiratory Diseases. This attack rate is comparable to what is usually seen among most seasonal influenza strains. Given that rate of 2009-H1N1 transition, the swine flu outbreak serves as “a stark reminder of the unpredictability of the timing and of the speed by which the pandemic situation can change,” Dr. Stöhr said.
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