News Author: Martha Kerr
July 27, 2009 — The US Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, is changing its recommendation for annual seasonal influenza vaccination for children aged 6 months to 18 years to a "full recommendation," Anne Schuchat, MD, director of the CDC’s National Center for Immunization and Respiratory Diseases, announced.
In addition, the CDC is advising a seasonal flu vaccine for anyone who feels they need one.
"While we are focusing a lot of attention on the 2009 H1N1 influenza virus, we do expect seasonal strains to emerge, and we are issuing updates of which strains to expect," Dr. Schuchat said. These include the A-H1N1, A-H3N2, and B strains, "which are available in this year’s vaccine," she noted. "This past year’s recommendations encouraged annual vaccination [of children]…. This year, [the CDC] is no longer just advising vaccination whenever feasible but is [issuing] a full-out recommendation" of the seasonal flu vaccine.
Only about 40% of the US population received a flu vaccine last year. The CDC is recommending and emphasizing "an intensification of use" of the vaccine.
The CDC has specifically recommended that healthcare workers be immunized, as well as that campers at sleepover summer camps and attendees of military academies where there have been notable outbreaks of influenza receive the flu vaccine and antiviral agents, but only if appropriate.
"I don’t think antiviral prophylaxis is a good idea," Dr. Schuchat said, noting that oseltamivir-resistant influenza strains have been reported.
Dr. Schuchat said that the latest laboratory-confirmed case count for the H1N1 influenza virus is 43,771 cases and 302 deaths, "but this is the last time we will be reporting cases in this way." Instead, the CDC will have a FluView Weekly Surveillance Report, updated every Friday, on its Web site.
The National Institutes of Health announced yesterday that clinical trials will begin as early as next week of 2 H1N1 influenza vaccine candidates in adults, either alone or in conjunction with the seasonal flu vaccine and, if safe, in children.
Sanofi Aventis and CSL Biotherapies, manufacturers of the 2 candidate vaccines, told a US Food and Drug Administration (FDA) advisory committee yesterday that they expect to have a vaccine available by October. Dr. Schuchat said that she is concerned that the flu season could be well underway by that time, because the school year begins within weeks in many areas.
The virus is unpredictable, she said, "skipping entire communities, while hitting others really hard." In addition, the virus can cause a wide spectrum of illness, from mild symptoms to respiratory arrest and neurological problems, including seizures. "That is why we are taking the virus so seriously." H1N1 often affects young, apparently healthy individuals, as well as those at high risk, and it could affect more than 40% of the population.
"We are preparing for the worst-case scenario of 60% of the population being affected," Dr. Schuchat said. "The value of worst-case scenario planning is that it allows for continuity planning."
The FDA’s Advisory Committee on Immunization Practices is set to meet July 29 to propose H1N1 vaccine recommendations. Children aged 0 to 4 years will likely be the top priority, followed by school-age children, healthcare workers, pregnant women, and adults with chronic diseases.
Today, the FDA announced it had issued an emergency use authorization for a third diagnostic test for the 2009 H1N1 influenza virus because a public health emergency involving H1N1 was declared on April 26, 2009. It is the Focus Diagnostics Influenza H1N1 (2009) Real-Time Reverse Transcription Polymerase Chain Reaction diagnostic test.
The emergency use authorization allows Focus Diagnostics to distribute the test to laboratories certified under the Clinical Laboratory Improvement Amendments to perform high-complexity tests. This test is intended for use in the detection of the 2009 H1N1 influenza virus in patients with symptoms of respiratory infection.
The test does not indicate the stage of infection, nor does a negative result preclude influenza virus infection, FDA officials emphasize.
MMWR Morb Mortal Wkly Rep. Posted online July 24, 2009.