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FDA Advisory Panel Recommends Licensure of Quadrivalent Conjugate Meningococcal Vaccine
Menactra vaccine is the first quadrivalent conjugate meningococcal vaccine for the prevention of meningococcal disease, a serious bacterial infection that can cause meningitis and sepsis (blood infection). This vaccine is designed to offer protection against four of the most common serogroups (A, C, Y, W-135) that cause meningococcal disease.
"Meningococcal meningitis is a potentially deadly infectious disease which affects children, adolescents and young adults in the U.S., and we are very pleased with the positive response from the FDA's Advisory Committee regarding our conjugate vaccine candidate, Menactra, that has the potential for substantial control of this serious disease," said Michael Decker, MD, MPH, vice president, scientific and medical affairs at Aventis Pasteur, the human vaccines business of Aventis, part of the sanofi-aventis Group. "Conjugate vaccines have been shown to induce a better and longer-lasting immune response than polysaccharide vaccines, and we believe that Menactra vaccine will offer these benefits to our nation's adolescents and young adults."
Although the FDA is not bound by the Advisory Committee's recommendation, the agency considers it carefully when deciding whether to license a vaccine for marketing.
In making its recommendation, the FDA Advisory Committee reviewed safety and immunogenicity data from six pivotal studies. The vaccine was shown to be immunogenic, safe and well tolerated.
Aventis Pasteur is currently constructing a new, state-of-the-art production facility at its U.S. site in Swiftwater, Pennsylvania, to produce Menactra meningococcal vaccine. The new facility is intended to ensure Aventis Pasteur's ability to meet anticipated global demand for the product.
"Aventis Pasteur is committed to satisfying all FDA requirements for vaccine licensure and, if licensed by the FDA, we intend to have the vaccine available as quickly as possible," said Dr. Decker.
About Meningococcal Disease
Meningococcal disease is a rare but devastating bacterial infection that strikes between 2,500 and 3,000 Americans every year, causing meningitis or sepsis in the majority of cases. Approximately 10 percent of individuals who contract meningococcal disease will die. Of survivors, up to one in five suffer long-term permanent disabilities such as hearing loss, brain damage and limb amputations. Meningococcal disease often begins with symptoms that can be mistaken for common viral illnesses, such as the flu. But unlike more common infections, meningococcal disease can progress very rapidly and kill an otherwise healthy young person in 48 hours or less.
Although disease rates are highest in infants, rates begin to rise again in early adolescence and peak between the ages of 15 and 24. During the 1990s, one study reported substantially increased incidence among 15- to 24- year-olds. Moreover, the fatality rate among people in this age group can reach 25 percent. Up to 83 percent of the cases in this age group were caused by the potentially vaccine-preventable serogroups that are included in Menactra vaccine.
About Conjugate Vaccine Technology
The current FDA-licensed meningococcal disease vaccine, Menomune(R)- A/C/Y/W-135 (Meningococcal Polysaccharide Vaccine, Groups A, C, Y and W-135 Combined), is made from a long chain of polysaccharides that come from the outer coat of the meningococcus bacterium, providing a limited duration of immunity. Duration of protection against meningococcal disease with Menomune-A/C/Y/W-135 vaccine is approximately three to five years.
Menactra vaccine is a conjugate vaccine, created by attaching the meningococcal polysaccharides to a carrier protein. Historically, conjugate vaccines have been shown to induce boostable memory responses and longer-lasting immune responses than polysaccharide vaccines. Since 1990, widespread use of conjugate vaccines in the U.S. against Haemophilus Influenzae type b (Hib) and Streptococcus pneumoniae have substantially reduced incidence of infections caused by these bacteria, both of which were common causes of meningitis.
Aventis Pasteur licensed the first conjugate vaccine in 1987 for protection against Haemophilus Influenzae type b, a leading cause of serious systemic bacterial disease in the U.S. Since the introduction of Hib conjugate vaccines such as ProHIBit, Haemophilus b Conjugate Vaccine (Diphtheria Toxoid-Conjugate), incidence of Hib invasive disease among children aged 4 years or younger has declined by 98 percent.
Impact of Conjugate Meningococcal Vaccine in the United Kingdom
Experience in the United Kingdom (U.K.) suggests that conjugate meningococcal vaccines provide significant benefits over traditional vaccines. From 1999 to 2000, the U.K. ran a national campaign to immunize 15 million children under age 17 with a conjugate vaccine that offered protection against one serogroup (the C serogroup) of meningococcal bacteria, which causes a greater proportion of cases in the U.K. than in the U.S. The campaign resulted in an 85 percent overall decline in cases and a 90 percent reduction in deaths from meningococcal serogroup C disease within one year.
Disease rates also declined 60 percent among unvaccinated children. This "herd immunity" effect is a result of the conjugate vaccine's ability to prevent carriage of the bacteria in the nose and throat and, thus, transmission of the bacteria to other persons. Carriage rates in children 15 to 17 years old decreased by 66 percent.
Obtaining similar public health benefits in the U.S. would require a vaccine that protects against multiple serogroups of meningococcal bacteria. Four serogroups (C, Y, W-135 and B) predominate in the U.S. Menactra vaccine contains three of these four serogroups, representing approximately two-thirds of meningococcal disease overall and up to 83 percent in the adolescent population. In the U.K., by contrast, two serogroups (C and B) predominate. Currently there is no vaccine available in the U.S. or the U.K. against meningococcal disease caused by the B serogroup.