Fluzone

Fluzone
source
Type	Inactivated influenza vaccine
Target	Influenza virus
Manufacturer	Sanofi Pasteur
Legal status	Prescription drug
Routes of administration	Intramuscular injection

Fluzone. It is an inactivated influenza vaccine manufactured by the pharmaceutical company Sanofi Pasteur. Approved for use by the Food and Drug Administration, it is designed to provide immunization against seasonal influenza viruses. The vaccine is a key component of annual public health strategies recommended by the Centers for Disease Control and Prevention and the World Health Organization.

Composition and formulation

The vaccine contains inactivated influenza A virus and influenza B virus strains that are selected annually based on global surveillance data from the World Health Organization. Each strain is propagated in embryonated chicken eggs, a standard method in influenza vaccine production, before being purified and inactivated. The final formulation is a sterile suspension that may include residual amounts of ovalbumin, formaldehyde, and octylphenol ethoxylate. Specific strains are updated each year to match the antigenic drift of circulating viruses, as determined by collaborations between the Food and Drug Administration and the Advisory Committee on Immunization Practices.

Indications and usage

This vaccine is indicated for active immunization against influenza caused by the virus subtypes contained in the formulation. It is approved for use in individuals six months of age and older, as per guidelines from the Centers for Disease Control and Prevention. Annual vaccination is recommended, particularly for high-risk groups including the elderly, young children, pregnant women, and those with chronic conditions like diabetes or cardiovascular disease. The Advisory Committee on Immunization Practices emphasizes its role in preventing complications that can lead to hospitalization or visits to the Mayo Clinic or Johns Hopkins Hospital.

Administration and dosage

The standard presentation is administered as a single 0.5 mL dose via intramuscular injection, typically into the deltoid muscle or the vastus lateralis muscle in infants. For adults aged 65 and older, a high-dose formulation is available, which contains a higher quantity of hemagglutinin antigen. Healthcare providers, including those at CVS Pharmacy and Walgreens clinics, follow protocols established by the Food and Drug Administration for storage and handling prior to administration. Revaccination is required each season due to the changing nature of the influenza virus.

Efficacy and clinical trials

Vaccine efficacy varies each season based on the match between the vaccine strains and circulating viruses, as monitored by the Centers for Disease Control and Prevention. Pivotal clinical trials, often conducted at institutions like the National Institutes of Health and the University of Michigan, have demonstrated that immunization significantly reduces the risk of influenza illness and related medical visits. The high-dose formulation has shown superior efficacy in older adults in studies published in the New England Journal of Medicine. Ongoing surveillance is conducted through networks like the U.S. Influenza Vaccine Effectiveness Network.

Safety and side effects

The most common adverse reactions are local, including pain, redness, and swelling at the injection site, as reported to the Vaccine Adverse Event Reporting System. Systemic reactions such as myalgia, headache, fatigue, and low-grade fever are generally mild and self-limiting. Severe allergic reactions, such as anaphylaxis, are rare but are detailed in the prescribing information from the Food and Drug Administration. Safety data is continually reviewed by the Advisory Committee on Immunization Practices and organizations like the Institute for Safe Medication Practices.

History and development

The vaccine lineage dates back to the pioneering influenza vaccine work supported by the United States Army during the 1940s. Sanofi Pasteur, a successor to companies like Connaught Laboratories, has been a major producer since the latter half of the 20th century. The high-dose formulation for older adults was approved following a clinical trial program reviewed by the Food and Drug Administration. The development process has evolved alongside global initiatives coordinated by the World Health Organization's Global Influenza Surveillance and Response System.

Available forms and storage

It is supplied in several presentations, including single-dose syringes and multi-dose vials, distributed to providers such as Kaiser Permanente and Public Health Service clinics. The vaccine must be stored at temperatures between 2°C and 8°C (36°F and 46°F) and should not be frozen, as per manufacturer guidelines from Sanofi Pasteur. The stability and potency are monitored under regulations enforced by the Food and Drug Administration. Specific formulations, such as the quadrivalent version, are packaged with information compliant with the National Drug Code directory.

Category:Vaccines Category:Influenza