Intranasal Influenza Vaccine Shows Higher Efficacy Rate Compared to Traditional Flu Shot
Monday May 3, 12:30 pm ET
Phase 3 Studies Involved 4,400 Children With a History of Respiratory Illness
SAN FRANCISCO, May 3 /PRNewswire-FirstCall/ -- Data were presented today from two Phase 3 studies showing that a live, attenuated intranasal influenza vaccine had higher efficacy rates and a similar safety profile to the traditional flu shot. The studies were conducted in children with a history of respiratory illness. The data were presented at the Pediatric Academic Societies' annual meeting in San Francisco, California.
"The deaths of 143 children during the last influenza season add to the growing body of evidence that influenza represents an important cause of morbidity and mortality in the pediatric population," said Edward Connor, M.D., senior vice president of clinical development and chief medical officer at MedImmune, Inc. "Increasing flu immunization rates and improving flu immunization methods are important goals of the scientific and public health communities.
"While data from previous trials with a live, attenuated influenza vaccine showed that it had a high rate of efficacy when compared to placebo in young children," Dr. Connor continued, "data from the studies presented this week provide evidence that a live, attenuated influenza vaccine may have a higher rate of protection against influenza in children when compared to the traditional injectible flu vaccine. Further, in these studies among children with asthma or a history of recurrent respiratory infections, no significant differences in the rates of wheezing was observed between recipients of the two types of influenza vaccines."
In 2003, the U.S. Food and Drug Administration approved FluMist(TM) (Influenza Virus Vaccine Live, Intranasal) as the first live, attenuated intranasal vaccine to prevent the flu. The new data come from two Phase 3 clinical trials using the next generation, refrigerator-stable formulation of FluMist, known as CAIV-T. These studies, conducted outside the U.S., are the first large studies to directly compare CAIV-T to the injectible flu vaccine (TIV) in preventing culture-confirmed influenza among children.
Phase 3 Clinical Trial Results
Prior to the 2002-2003 flu season, approximately 2,200 infants and children six months through 71 months of age with a history of recurrent respiratory tract infections received either two intranasal doses of CAIV-T or two doses of TIV to compare the efficacy and safety of the vaccines. Children receiving CAIV-T in this study had a 53-percent reduction in culture-confirmed influenza compared to those receiving TIV.
In a second trial, approximately 2,200 children and adolescents from six years through 17 years of age with a history of asthma received either one intranasal dose of CAIV-T or one traditional dose of TIV prior to the 2002- 2003 flu season. Children receiving CAIV-T in this study had a 35-percent reduction in culture-confirmed influenza compared to those receiving TIV.
In both trials, no significant differences were observed in the rates of wheezing post-vaccination.
These CAIV-T studies were conducted by Wyeth (NYSE: WYE - News) under a collaboration with MedImmune (Nasdaq: MEDI - News). On April 26, 2004 the two companies announced that they had entered into agreements to dissolve their collaboration. Pending federal antitrust clearance, MedImmune will assume full responsibility for the manufacturing, marketing and selling of FluMist, CAIV-T and all related technology.
About CAIV-T
CAIV-T is an investigational intranasal, cold-adapted trivalent influenza vaccine. It is the next generation, refrigerator-stable formulation of FluMist, which is a frozen, live attenuated cold-adapted trivalent influenza vaccine. To date, the safety, tolerability and efficacy of CAIV-T has been studied in both healthy and at-risk populations between the ages of 6 weeks and 98 years. Some of these data were presented in October 2003 at the Fifth Annual Options for the Control of Influenza Conference in Okinawa, Japan... |
