Flu vaccine production pdf#

Figure 3 also shows that the number of strains isolated varies dramatically from season to season. Every year in the United States, approximately 36,000 people die, 114,000 are hospitalized, $600 million are spent in direct costs to the health care system, and the country incurs $1 billion in economic costs.įigure 2 shows the seasonal occurrence of influenza Figure 3 shows the absolute numbers of strains isolated in each season, as well as the proportion of strains isolated over the flu season. Ninety percent of deaths in people 65 and older are the result of influenza with associated pneumonia. Seasonal influenza is the seventh leading cause of death in the United States and the leading cause of death in children ages 1 to 4 years. Examples include FluMist?, made by MedImmune Vaccines Inc., and a similar formulation produced in St. Live attenuated influenza vaccines represent only a small portion of the licensed influenza vaccines. The vaccine primarily discussed in this paper is Fluzone?, a split (subvirion) vaccine manufactured by Sanofi Pasteur. Inactivated vaccines, which account for more than 90 percent of vaccine sales worldwide, include vaccines made from (1) whole viruses (2) viruses subject to two different splitting procedures (a simple detergent split with enrichment or a subvirion highly enriched for HA and NA) (3) virosomal vaccines, which are primarily licensed in the European Union (EU) and (4) influenza vaccines formulated with adjuvant to increase their potency. There are generally two types or classes of influenza vaccines: (1) inactive vaccines and (2) live attenuated vaccines. M2, NP, and other antigenic components, although they probably play a role in cellular immunity, are not part of the yearly evaluation or licensing process for seasonal influenza vaccines.

Antibody titers are often expressed in terms of hemagglutinin inhibition (HAI), which becomes a correlate of protection or immunity for influenza vaccines. The efficacy of vaccines for Type A and Type B influenza is measured primarily by their ability to stimulate antibodies to the HA antigen. If two viruses co-infect a single host, the separate gene segments shown in Figure 1 can reassort to produce novel and unexpected combinations, some of which are extremely virulent in humans. Therefore, formulation of the influenza vaccine must be changed on a yearly basis. The HA and NA antigens undergo both mutation and reassortment, and, most significant, both antigens are subject to antigenic drift, subtle mutations that occur continually. Throughout the vaccine manufacturing process-inactivation, extraction of the virus envelope, and purification-both the quantity and inherent antigenicity, or immunogenicity, of the HA and NA antigens must be preserved.

Flu vaccine production pdf#

Figure 1(see PDF version for figures) shows the virus envelope with the HA and NA surface antigens. The two influenza viruses that are medically and clinically important to the human population, known as Type A and Type B, are segmented, negative-strand genomes with an envelope that contains two major antigens, hemagglutinin (HA) and neuraminadase (NA), and a minor component designated M2. H5N1 Influenza Virus Vaccine, manufactured by Sanofi Pasteur, Inc.Despite improvements in technology and increased automation, egg-based vaccine production still has a long timeline.Persons who provide important community services (such as police, fire department personnel, emergency medical services) should consider getting a flu vaccine so that those services are not disrupted during a flu outbreak. A flu vaccine can be given to anyone who wants to avoid the flu (persons over 6 months of age). People in high-risk groups and people who are in close contact with those at high risk should get a flu vaccine every year as recommended by the Advisory Committee on Immunization Practices (ACIP). A lot of the illness and death caused by the flu can be prevented by a yearly flu vaccine. Influenza usually comes on suddenly and may include these symptoms: fever, headache, malaise (a feeling of being ill and without energy that can be extreme), cough, sore throat, nasal congestion and body aches. The flu is different from a cold, mainly because the symptoms and complications are more severe. Influenza viruses infect the respiratory tract (nose, throat, and lungs) in humans. Influenza, also known as the flu, is a contagious disease that is caused by influenza viruses.