NCSL Influenza Report
February 2007
Overview
A global emergence of avian influenza has made state and local authorities mindful of the potential impact a pandemic of any origin may have on our daily lives. Even the most common forms of influenza will hospitalize on average more than 200,000 people every year. According to the Centers for Disease Control and Prevention (CDC), infections caused by influenza virus A or B have resulted in 36,000 deaths in the United States between 1990 and 1999. Over the last three years avian influenza has claimed the lives of 241 people in 10 countries as well as adversely affecting the poultry industry worldwide. Many scientists believe it is only a matter of time until the next influenza pandemic occurs. Shortages of the influenza vaccine supply in three of the last five flu seasons and the possibility of an outbreak of more serious strains of influenza have called into question the nations ability to endure a pandemic outbreak.
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Vaccines/Antivirals, Medical Supplies and Resources |
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Seasonal Flu
The Centers for Disease Control and Preventions (CDC) recommends October through November as the best time to be vaccinated because the flu season often begins in late November to December time frame and peaks between late December and early March. It take approximately two weeks after vaccination for antibodies to develop in the body and provide protection against an influenza virus infection.
Flu vaccine production and distribution is largely a private-sector responsibility. Unfortunately, distribution delays or vaccine supply shortages have occurred in the United States in several of the last few influenza seasons. According to the CDC, influenza vaccine manufacturers are projecting that approximately 100 million doses of influenza vaccine will be available in the United States for the 2006--07 influenza season, an amount that is approximately 16% more doses than were available for the 2005--06 season. An additional 15 million--20 million doses might be available if a new vaccine is licensed in 2006. (Information about the status of licensure of new vaccines is available in Red Book Online: Status of Licensure and Recommendations for New Vaccines .) However, influenza vaccine distribution delays or vaccine shortages remain possible in part because of the inherent critical time constraints in manufacturing the vaccine given the annual updating of the influenza vaccine strains.
The 2006 recommendations include six principal changes or updates:
- ACIP recommends that healthy children aged 24--59 months and their household contacts and out-of-home caregivers be vaccinated against influenza (see Target Groups for Vaccination). This change extends the recommendations for vaccination of children so that all children aged 6--<59 months receive annual vaccination.
- ACIP emphasizes that all children aged 6 months--<9 years who have not been previously vaccinated at any time with either live, attenuated influenza vaccine (LAIV) or trivalent inactivated influenza vaccine (TIV) should receive 2 doses of vaccine. Those children aged 6 months--<9 years who receive TIV should have a booster dose of TIV administered >1 month after the initial dose, before the onset of influenza season, if possible. Those children aged 5--<9 years who receive LAIV should have a second dose of LAIV 6--10 weeks after the initial dose, before the influenza season, if possible. If a child aged 6 months--<9 years received influenza vaccine for the first time during a previous season but did not receive a second dose of vaccine within the same season, only 1 dose of vaccine should be administered this season (see Efficacy and Effectiveness of Inactivated Influenza Vaccine, Children; TIV Dosage; and LAIV Dosage and Administration).
- To ensure optimal use of available doses of influenza vaccine, projected to be approximately 100 million doses, health-care providers, those planning organized campaigns, and state and local public health agencies should 1) develop plans for expanding outreach and infrastructure to vaccinate more persons than during the previous year and 2) develop contingency plans for the timing and prioritization of administering influenza vaccine, if the supply of vaccine is delayed and/or reduced because of the complexity of the production process (see Influenza Vaccine Supply and Timing of Annual Influenza Vaccination).
- ACIP emphasizes that influenza vaccine should continue to be offered throughout the influenza season even after influenza activity has been documented in a community. In addition, ACIP encourages all community vaccinators and public health agencies to schedule clinics that serve target groups and to help extend the routine vaccination season by offering at least one vaccination clinic in December (see Influenza Vaccine Supply and Timing of Annual Influenza Vaccination).
- ACIP recommends that neither amantadine nor rimantadine be used for the treatment or chemoprophylaxis of influenza A in the United States because of recent data indicating widespread resistance of influenza virus to these medications. Until susceptibility to adamantanes has been re-established among circulating influenza A viruses, oseltamivir or zanamivir may be prescribed if antiviral treatment or chemoprophylaxis of influenza is indicated (see Recommendations for Using Antiviral Agents for Influenza).
- The 2006--07 trivalent vaccine virus strains are A/New Caledonia/20/1999 (H1N1)-like, A/Wisconsin/67/2005 (H3N2)-like, and B/Malaysia/2506/2004-like antigens. For the A/Wisconsin/67/2005 (H3N2)-like antigen, manufacturers may use the antigenically equivalent A/Hiroshima/52/2005 virus; for the B/Malaysia/2506/2004-like antigen, manufacturers may use the antigenically equivalent B/Ohio/1/2005 virus (see Influenza Vaccine Composition).
CDC Materials
Avian Influenza
Background
A growing concern over increasing numbers of human cases of avian influenza since 1997 around the world has urged leaders to address ways of lessening the consequences of a pandemic. In 2004, the World Health Organization (WHO) published planning guidance[1] on the use of influenza vaccines and antivirals for treatment during a pandemic, recommending against the development of an influenza vaccine stockpile since vaccines must be produced in correspondence with the prevailing strains of flu for the prevailing year. In addition, they sited that existing technology would not support the production of a sufficient supply of vaccine to meet the need until well after the initial phase of the pandemic.
However, the guidance does recommend the stockpiling of antivirals since the drugs are relatively stable and they are likely to be an effective agent against the spread of disease. Antiviral drugs are used to kill or prevent the growth of viruses. Viral infections are much harder to treat as compared to bacterial infections because viruses live inside our cells, making it harder for the immune system to locate and attack them. According to a report[2] published by the Centers for Disease Control and Prevention (CDC), two groups of antiviral drugs are available for the treatment and prophylaxis of influenza. These are the adamantanes (amantadine and rimantadine) and the neuraminidase inhibitors (oseltamivir or Tamiflu and zanamivir or Relenza). Because of concerns relating to certain adverse affects of adamantanes, the CDC has recommended against their use in the treatment of or prophylaxis of influenza A strains.
Neuraminidase inhibitors have been found to block viral enzymes in both influenza A and B strains and when used within 48 hours of onset of illness these drugs decrease the severity and duration of disease[3]. To have a sufficient stockpile WHO recommends[4] that communities plan to purchase enough antiviral drugs to be able to provide treatment to 25 percent of an affected population and enough prophylactic courses for the additional 75 percent in the affected area.
Recommendations and Federal Assistance
The production and stockpiling of vaccines, antivirals and medical materials is a primary goal in preparing for a possible pandemic as outlined in the National Strategy for Pandemic Influenza. The plan encourages states to develop a stockpile of antivirals to support response activities sufficient enough to meet the demands of the medical requirements presented in a pandemic.
The federal government recommends that a stockpile of 81 million courses of antivirals be maintained in the United States to cover approximately 25 percent of the U.S. population. The Department of Health and Human Services (HHS) is stockpiling antivirals and is allocating them to states based on population. Purchases in FY2006 will bring the nation’s stockpile of antivirals to 20 million courses by the end of this year (a course is the supply needed to treat one person). With anticipated FY2007 funding, HHS plans to order an additional 24 million courses which will likely be delivered in 2008. An additional 31 million courses (FY2006) are available for state purchase under negotiated rates with HHS providing a 25 percent subsidy. State governors were asked to notify HHS of their plans to purchase their allocated antivirals by August 1, 2006. States also have the option to purchase additional treatment courses beyond their allocation without the 25 percent subsidy but at the federally negotiated rate.
Congress allocated $350 million this year to assist with state and local preparedness. The initial allocation of $100 million in February was intended for development and exercising of state pandemic response plans. Recipients of the funding are required to use assessment tools developed by the CDC to identify gaps in their plans and establish an approach for correction action. The remaining $250 million of the assistance funding has been divided into a $225 million formula award and a $25 million competitive award. To receive a portion of the $225 million, state will be required to address and plan for five target capabilities including the development and testing of an antiviral distribution plan. Guidance for the remaining $25 million is pending.
The responsibility of maintaining and distributing antivirals will inevitably fall to the states. HHS is developing a model distribution plan to provide assistance to states with their planning. States will have to consider issues concerning priority recipients of antivirals, informed consent in a mass intervention, and follow-up and reporting of adverse reactions to antiviral administration.
[2] Gani R, Hughes H, Fleming D, Griffin T, Medlock J, Leach S. Potential impact of antiviral drug use during influenza pandemic. Emerg Infect Dis [serial on the Internet]. 2005 Sept [date cited]. Available from http://www.cdc.gov/ncidod/EID/vol11no09/04-1344.htm
[4] World Health Organization (WHO), “WHO pandemic influenza draft protocol for rapid response and containment,” May 30, 2006, Washington, D.C., (http://www.who.int/csr/disease/avian_influenza/guidelines/protocolfinal30_05_06a.pdf). [Internet document.]
November 13, 2006--U.S. Food and Drug Administration issues safety alert to health professionals for Tamiflu to highlight changes in precautions for pediatric use, http://www.fda.gov/medwatch/safety/2006/safety06.htm#tamiflu.
Roche and FDA notified healthcare professionals of revisions to the PRECAUTIONS/Neuropsychiatric Events and Patient Information sections of the prescribing information for Tamiflu, indicated for the treatment of uncomplicated acute illness due to influenza infection in patients 1 year and older who have been symptomatic for no more than 2 days and for the prophylaxis of influenza in patients 1 year and older. There have been post marketing reports (mostly from Japan) of self-injury and delirium with the use of Tamiflu in patients with influenza. People with the flu, particularly children, may be at an increased risk of self-injury and confusion shortly after taking Tamiflu and should be closely monitored for signs of unusual behavior. A healthcare professional should be contacted immediately if the patient taking Tamiflu shows any signs of unusual behavior.
[November 13, 2006 - Letter - Roche]
[November 13, 2006 - Prescribing Information - Roche]
[November 13, 2006 - Patient Package Insert - Roche]
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For further information, please call NCSL staff Joy Johnson Wilson, Health Policy Director at 202-624-8689 or Rachel Morgan RN, BSN, Senior Health Policy Specialist at 202-624-3569.
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