News Pressroom

May 14, 2005

Data From Several Studies of Medimmune's Intranasal Influenza Vaccines Support Broad Protection Against Influenza

- Results Presented at Pediatric Academic Societies Annual Meeting -

WASHINGTON, May 14, 2005 /PRNewswire-FirstCall via COMTEX/ -- MedImmune, Inc. (Nasdaq: MEDI) announced today data from several studies that provide evidence that its live, attenuated intranasal influenza vaccines may provide broad protection against influenza. Results from clinical trials of the currently marketed FluMist(R) (Influenza Vaccine Live, Intranasal) and the investigational, next-generation refrigerator stable CAIV-T (cold adapted influenza vaccine, trivalent) are being presented at the annual meeting of the Pediatric Academic Societies (PAS) in Washington, DC, beginning on May 14, 2005.

"These presentations add to the growing body of data regarding the potential advantages of live, attenuated intranasal influenza vaccine technology," said Francois Lebel, M.D., vice president, medical affairs. "The studies support previous clinical observations that this vaccine technology appears to provide benefit during years in which the circulating strains of influenza were mismatched to the influenza vaccines administered in the community."

Each year, strains for the annual influenza vaccines are chosen in advance of the flu season. In some seasons, the predominantly circulating strains do not match those within the vaccines. When this "vaccine mismatch" occurs, it is more difficult for influenza vaccines to provide comprehensive protection. Significant vaccine mismatch has occurred in four of the last eight influenza seasons, including both the 2003-2004 and 2004-2005 seasons. Data from three studies and a retrospective review support the conclusion that FluMist helps provide protection in both matched and mismatched influenza seasons.

  • "Live Attenuated Influenza Vaccine (LAIV) Administration in Schoolchildren Coincident With the 2003-2004 Outbreak Provided Herd Immunity Against a Drifted Influenza Variant A/Fujian/411/2002 (H3N2)." Results from this herd immunity study indicated that immunizing school- aged children helped protect both the children and the extended community from influenza during a mismatched season.


  • "Protection of Live Attenuated Intranasal Influenza Vaccine-Trivalent (FluMist(R)) Against Pneumonia and Influenza (P-I) in School-Aged Children in the 2003-2004 Influenza Type A (H3N2) Outbreak." Data from this pilot, National Institutes of Health-sponsored, community-based intervention trial suggest that FluMist may be efficacious when administered during an influenza outbreak when the predominant circulating strains were mismatched to the vaccine.


  • "Cross-Protection Against Antigenic Variants by Live-Attenuated Influenza Vaccine in Children." This is a retrospective review of mismatch efficacy of live attenuated intranasal vaccine in children 6 months to 18 years of age from 1996 to 2002. Efficacy against the mismatched strain A/H3N2 was 86 percent to 89 percent, and efficacy against the mismatched type B strains was 50 percent to 66 percent.


  • "A Pilot Study of the Effectiveness of a School-Based Influenza Vaccination Program Using the Nasally Administered Vaccine FluMist." In this pilot intervention study, children who were immunized with FluMist in their schools experienced a reduction in medical visits and missed school days in the mismatched 2003-2004 influenza season. Overall school absenteeism was not statistically different among the intervention and control schools.

Two Phase 3 placebo-controlled studies presented at the PAS meeting provide evidence for the safety and efficacy of CAIV-T in young children, including:

  • "Efficacy of a Cold-Adapted, Live Attenuated, Influenza Vaccine in Children Aged 6 to <36 Months Attending Day Care Centers in Europe and Israel Against Culture-Confirmed Influenza"


  • "Efficacy and Safety of a Live Attenuated, Trivalent Influenza Vaccine (CAIV-T) in Children Living in South East Asia Against Community Acquired Culture-Confirmed Influenza"

These studies add to the body of data presented at last year's PAS annual meeting, which included two international Phase 3 studies in children with a history of respiratory illness. Results from the studies presented in 2004 demonstrated a 35 percent to 53 percent relative decrease in influenza with CAIV-T as compared to the traditional injectable vaccine.

About FluMist

FluMist was approved by the FDA in June 2003. It is the first live, attenuated influenza vaccine in the U.S. that is indicated for active immunization for the prevention of disease caused by influenza A and B viruses in healthy children and adolescents, 5 to 17 years of age, and healthy adults, 18 to 49 years of age. There are risks associated with all vaccines including FluMist. Like any vaccine, FluMist does not protect 100 percent of individuals vaccinated. In placebo-controlled clinical trials, the most common solicited adverse events in the indicated population of 2,762 included runny nose/nasal congestion, headache, cough, sore throat, tiredness/weakness, irritability, decreased activity and muscle aches. For full prescribing information for FluMist, see the company's website at http://www.medimmune.com.

About MedImmune, Inc.

MedImmune strives to provide better medicines to patients, new medical options for physicians, rewarding careers to employees, and increased value to shareholders. Dedicated to advancing science and medicine to help people live better lives, the company is focused on the areas of infectious diseases, cancer and inflammatory diseases. With approximately 2,000 employees worldwide, MedImmune is headquartered in Maryland. For more information, visit the company's website at http://www.medimmune.com.

This announcement contains, in addition to historical information, certain "forward-looking statements" regarding the results of clinical trials for FluMist and CAIV-T. Such forward-looking statements are based on current expectations and involve inherent risks and uncertainties, including factors that could delay, divert or change current expectations and could cause actual outcomes and results to differ materially from current expectations. In addition to risks and uncertainties discussed in MedImmune's filings with the U.S. Securities and Exchange Commission, no assurance exists that development efforts for CAIV-T will succeed, that CAIV-T will receive required regulatory approval or that, even if regulatory approval is received, CAIV-T will be commercially successful. MedImmune undertakes no obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise except as may be required by applicable law or regulation.

SOURCE MedImmune, Inc.

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