Influenza Virus Vaccine Trivalent Types A and B Whole Virion and Subvirion
Active Immunizing Agent
Description: Fluzone is a trivalent, inactivated influenza vaccine prepared from virus grown in allantoic fluids of chick embryos. The viruses are inactivated with formaldehyde and purified in a linear sucrose density gradient solution using a continuous flow centrifuge. The virus is either further purified (whole virion) or chemically disrupted and then further purified (subvirion). Thimerosal 0.01% is added as a preservative.
Indications And Clinical Uses: The National Advisory Committee on Immunization recommends:
People at High Risk: Vaccination of people at high risk is the single most important measure for reducing the impact of influenza. Priority should be given to ensure annual vaccination of people in the following groups:
Adults and children with chronic cardiac or pulmonary disorders (including bronchopulmonary dysplasia, cystic fibrosis, and asthma) severe enough to require regular medical follow-up or hospital care: Chronic cardiac and pulmonary disorders are by far the most important risk factors for influenza-related death.
People of any age who are residents of nursing homes and other chronic care facilities: Such residents generally have one or more of the medical conditions outlined in the first group. In addition, their institutional environment may promote spread of the disease. Recent studies have shown that the use of vaccine in this setting will decrease occurrence of illness and has an even greater impact in reducing the rates of hospitalization, pneumonia and death.
Geriatrics: The risk of severe illness and death related to influenza is moderately increased in healthy people in this age group but is not nearly as great as in people with chronic underlying disease.
Adults and children with chronic conditions such as diabetes and other metabolic diseases, cancer, immunodeficiency, immunosuppression, renal disease, anemia and hemoglobinopathy: The degree of risk associated with chronic renal and metabolic diseases in children in uncertain but this uncertainly should not preclude consideration of vaccination.
Children and adolescents (age 6 months to 18 years) with conditions treated for long periods with acetylsalicylic acid: This therapy might increase the risk of Reye's syndrome after influenza.
People capable of transmitting influenza to those at high risk: People who are potentially capable of transmitting influenza to those at high risk should receive annual vaccination.
Health care and other personnel who have extensive contact with people in the high risk groups previously described: The potential for infecting people at high risk outlined above, particularly those in institutions, may be reduced through vaccination programs for health care personnel.
Household contacts (including children) of people at high risk who either cannot be vaccinated or may respond inadequately to vaccination: Because low antibody responses to influenza vaccine may occur in some people at high risk (e.g., the elderly, people with immunodeficiency), annual vaccination of their household contacts may reduce the risk of influenza exposure.
Other People: People who provide essential community services may be considered for vaccination to minimize disruption of routine activities in epidemics. The vaccine may also be administered to those who wish to reduce their chances of acquiring infection.
Foreign Travelers: For vaccine eligible persons embarking on foreign travel, their influenza vaccination history and the seasonal occurrence of influenza at their destination should be reviewed. If no vaccine was received during the previous fall, vaccination before travel should be considered. Influenza can occur throughout the year in the tropics. Persons in the high-risk categories especially should be encouraged to receive the vaccine. The most current vaccine should be used. High-risk persons given the previous season's vaccine before travel should be revaccinated in the fall/winter with current vaccine.
Contra-Indications: Influenza virus vaccine is propagated in eggs. Therefore, this vaccine should not be administered to anyone with a history of hypersensitivity (allergy) and especially anaphylactic reactions to eggs or egg products. It is also a contraindication to administer this vaccine to individuals known to be sensitive to thimerosal. In any case, epinephrine HCl solution (1:1 000) must be immediately available should an acute anaphylactic reaction occur due to any component of the vaccine.
The vaccine should not be used in the presence of acute febrile illnesses or active infection.
Manufacturers' Warnings In Clinical States: If influenza virus vaccine is used in persons with malignancies receiving immunosuppressive therapy, or those who are otherwise immunocompromised, the expected immune response may not be obtained.
Although influenza vaccination can inhibit the clearance of warfarin and theophylline, clinical studies have consistently failed to show any adverse effects attributable to these drugs in people receiving influenza vaccine.
Influenza virus is remarkably capricious in that significant antigenic changes may occur from time to time. It is known definitely that influenza virus vaccine, as now constituted, is not effective against all possible strains of influenza virus. Protection is afforded most people only against those strains of virus from which the vaccine is prepared or against closely related strains.
As with any vaccine, vaccination with influenza virus vaccine may not result in sero-conversion in all individuals given the vaccine.
Precautions: The possibility of allergic reactions in individuals sensitive to the components of the product should be borne in mind. Epinephrine HCl solution (1:1 000) should be readily available for use in case an anaphylactic or acute hypersensitivity reaction occurs.
During the course of any febrile illness or other active infection, use of influenza virus vaccine should be delayed.
Prior to an injection of any vaccine, all known precautions should be taken to prevent side reactions. This includes a review of the patient's history with respect to possible sensitivity to the vaccine or similar vaccine.
A separate sterile syringe and needle should be used for each patient to prevent transmission of hepatitis B virus or other infectious agents from one person to another. Do not recap needles.
Children: The use of influenza vaccine in infants less than 6 months of age is not recommended.
Pregnancy: NACI recommends that pregnant women in high-risk groups for influenza complications should be vaccinated.
Simultaneous Administration of Other Vaccines: Pneumococcal vaccine and influenza vaccine can be given at the same time at different sites without an increase in side effects, but it should be emphasized that, whereas influenza vaccine is given annually, pneumococcal vaccine should be given only once to adults. Detailed immunization records should be provided to each patient to help ensure that additional doses of pneumococcal vaccine are not given. Children at high risk may receive influenza vaccine at the same time as routine pediatric vaccines but at separate sites with separate syringes.
Adverse Reactions: Because influenza vaccine contains only noninfectious viruses, it cannot cause influenza. Respiratory disease after vaccination represents coincidental illness unrelated to influenza vaccination. The most frequent side effect of vaccination is soreness at the vaccination site that lasts for up to 2 days; this is reported by fewer than one-third of vaccinees. In addition, 2 types of systemic reactions have occurred: 1. Fever, malaise, myalgia, and other systemic symptoms occur infrequently and most often affect persons who have had no exposure to the influenza virus antigens in the vaccine (e.g., young children). These reactions begin 6 to 12 hours after vaccination and can persist for 1 to 2 days.
2. Immediate - presumably allergic - reactions (such as hives, angioedema, allergic asthma, or systemic anaphylaxis), occur rarely after influenza vaccination. These reactions probably result from hypersensitivity to some vaccine component - the majority are most likely related to residual egg protein. Although current influenza vaccines contain only a small quantity of egg protein, this protein may induce immediate hypersensitivity reactions among persons with severe egg allergy. Individuals with anaphylactic hypersensitivity to eggs should not be given influenza vaccine. Such persons include those who, on eating eggs, develop swelling of the lips or tongue or experience acute respiratory distress or collapse.
Prophylactic acetaminophen may decrease the frequency of some side effects in adults.
Children: In children aged 2 to 12 years fever and local reactions are no more frequent after administration of split-virus vaccine than after placebo injections. In those less than 24 months of age fever occurs more often but is seldom severe.
Unlike the 1976-77 swine influenza vaccine, subsequent vaccines prepared from other virus strains have not been associated clearly with an increased frequency of Guillain-Barré syndrome (GBS). However, it is difficult to make a precise estimate of risk for a rare condition such as GBS. In 1990-91 in the United States, although there was no overall increase in frequency of GBS among vaccine recipients, there may have been a small increase in GBS cases in vaccinated persons 18 to 64 years of age, but not in those aged ³65 years. In contrast to the swine influenza vaccine, the epidemiologic features of the possible association of the 1990-91 vaccine with GBS were not as convincing. Even if GBS were a true side effect, the very low estimated risk for GBS is less than that of severe influenza that could be prevented by vaccine. Influenza vaccine is not known to predispose to Reye's syndrome.
Other neurologic illnesses, including facial paralysis, encephalitis, encephalopathy, demyelinating disease and labyrinthitis following influenza vaccination have been reported. Relationship to vaccine other than temporal has not been established.
Fatalities from a variety of other causes have been reported in the high-risk population following influenza vaccination without the establishment of a definite causal relationship.
Health care providers should report any occurrences temporally related to the administration of the product in accordance with local requirements and to the Medical Director, Connaught Laboratories Limited, 1755 Steeles Avenue West, Willowdale, Ontario, Canada, M2R 3T4.
Dosage And Administration: See Table I.
Do not inject i.v. Injections of influenza virus vaccine are recommended to be given i.m., preferably in the deltoid muscle or anterolateral thigh. Other routes of administration of inactivated influenza vaccine should be avoided because of unpredictable results. Before injection, the skin over the site to be injected should be cleansed with a suitable germicide. After insertion of the needle, aspirate to insure the needle has not entered a blood vessel. The product may contain a precipitate which settles on standing, therefore the vial should be shaken vigorously before withdrawing each dose. Shake the prefilled syringe well before administering dose.
Whole virion vaccine: Not recommended for children under 12 years of age. Adults and children 13 years of age and older: one 0.5 mL injection.
Subvirion vaccine: May be used for all age groups. It is not recommended for infants under 6 months of age.
Split-virus vaccines, produced by chemically disrupting the influenza virus, are generally associated with somewhat fewer side effects in children and young adults than are whole-virus vaccines; consequently, only split-virus vaccines are recommended for persons less than 13 years of age.
Availability And Storage: Vials of 5 mL. Prefilled syringes of 0.5 mL. Store between 2 and 8°C. Potency is destroyed by freezing; do not use influenza vaccine that has been frozen.
Reviewed Reviewed 1996