VIRIONZA Influenza Vaccine (Split Virion), Inactivated is a seasonal influenza vaccine containing inactivated, split-virus influenza antigens. It is designed to stimulate the immune system to develop protection against influenza virus strains included in the vaccine. VIRIONZA is supplied as a 0.5 mL pre-filled syringe, with 15 µg of hemagglutinin per included influenza strain, according to the product information provided.
Influenza vaccination is an important preventive measure because influenza viruses continually change, and vaccine compositions are updated periodically to better match circulating viruses. The World Health Organization (WHO) reviews influenza surveillance data twice each year and issues recommendations for vaccine composition for upcoming northern and southern hemisphere seasons.
Important: The influenza strains listed below correspond to the VIRIONZA product information supplied for this product. Influenza vaccine compositions can change by season, so customers should check the product packaging, batch information and applicable local guidance before vaccination.
What Is VIRIONZA Influenza Vaccine?
VIRIONZA is an inactivated split-virion influenza vaccine. Unlike live attenuated influenza vaccines, an inactivated influenza vaccine does not contain live influenza virus capable of causing influenza infection.
The vaccine contains purified influenza virus components, including hemagglutinin (HA). Hemagglutinin is a surface protein of influenza viruses and an important antigen that stimulates the body's immune response after vaccination.
The vaccine is intended to help prevent seasonal influenza caused by influenza virus strains related to the antigens included in the vaccine. It is not a treatment for an existing influenza infection.
VIRIONZA Influenza Vaccine Composition
According to the product information supplied for VIRIONZA, each 0.5 mL dose contains 15 µg of hemagglutinin from each of three influenza strains:
| Influenza strain | Hemagglutinin |
|---|---|
| A/Victoria/4897/2022 (H1N1)pdm09-like virus | 15 µg |
| A/Croatia/10136RV/2023 (H3N2)-like virus | 15 µg |
| B/Austria/1359417/2021 (B/Victoria lineage)-like virus | 15 µg |
These three strains match the WHO-recommended egg-based trivalent influenza vaccine composition for the 2025–2026 Northern Hemisphere season.
However, WHO subsequently recommended different strains for the 2026–2027 Northern Hemisphere season, including A/Missouri/11/2025-like, A/Darwin/1454/2025-like and B/Tokyo/EIS13-175/2025-like viruses for egg-based vaccines. Therefore, the strain composition printed on a specific VIRIONZA package should be checked before describing it as a current-season formulation.
What Does “Split Virion” Mean?
A split-virion influenza vaccine is produced by processing the influenza virus particles so that the vaccine contains disrupted or “split” viral components rather than intact infectious virus.
The manufacturing information supplied for VIRIONZA describes a process involving:
- Propagation of influenza virus strains in embryonated chicken eggs
- Harvesting of the virus-containing material
- Inactivation
- Concentration
- Purification
- Splitting of the virus particles
- Preparation of the final vaccine dose
The resulting vaccine contains influenza antigens that can stimulate an immune response without using a live, infectious influenza virus.
What Is VIRIONZA Influenza Vaccine Used For?
VIRIONZA is used for the prevention of seasonal influenza caused by influenza virus strains related to those included in the vaccine.
Influenza vaccination can reduce the risk of influenza illness and can also reduce the severity of illness and influenza-related complications in people who become infected despite vaccination. CDC guidance states that seasonal influenza vaccination is recommended annually for people aged 6 months and older who do not have a contraindication, although individual vaccine products have their own approved age ranges.
For VIRIONZA specifically, the supplied product information states that it is intended for eligible individuals including children aged 3 years and above, particularly people considered at increased risk of influenza complications.
Who May Benefit From Influenza Vaccination?
Influenza vaccination is particularly important for people who have an increased risk of serious influenza complications.
Depending on age, health status and applicable vaccination recommendations, this can include:
- Older adults
- Young children within the approved age range of the vaccine
- People with certain chronic medical conditions
- People with weakened immune systems
- Pregnant individuals
- Healthcare workers
- People living in settings where influenza can spread easily
- People who may be exposed to influenza during seasonal outbreaks
CDC notes that vaccination is particularly important for people at higher risk of serious influenza complications.
The suitability of VIRIONZA should be determined according to its approved product information and advice from a doctor or qualified healthcare professional.
How Does the Influenza Vaccine Work?
After vaccination, the immune system recognizes influenza antigens contained in the vaccine and develops an immune response.
The vaccine does not guarantee that a vaccinated person will never develop influenza. Influenza viruses continually evolve, and protection depends partly on how closely vaccine strains match viruses circulating during a particular season.
WHO regularly updates influenza vaccine recommendations because influenza viruses are constantly changing. WHO's vaccine composition recommendations are based on global influenza surveillance and expert assessment.
VIRIONZA 15 µg/0.5 mL Dosage
The supplied VIRIONZA presentation contains:
0.5 mL per pre-filled syringe
15 µg hemagglutinin per included influenza strain.
The vaccine should be administered according to the approved product information and vaccination recommendations applicable to the patient.
Because influenza vaccine schedules can differ according to age, previous vaccination history and the specific vaccine formulation, do not determine an individual vaccination schedule from an online product description alone.
A doctor, pharmacist or qualified vaccination professional should determine the appropriate dose and schedule.
How Is VIRIONZA Administered?
VIRIONZA is an injectable influenza vaccine intended for administration by a qualified healthcare professional.
The product information supplied describes administration by the intramuscular route.
Patients should not attempt to administer the vaccine themselves unless specifically instructed and authorized under applicable medical guidance.
Before vaccination, the healthcare professional should review relevant medical history, allergies, previous vaccine reactions and other factors that may affect suitability.
Important Precautions Before Influenza Vaccination
Tell your healthcare professional if you:
- Have previously experienced a severe allergic reaction after an influenza vaccine
- Have a known allergy to any vaccine component
- Have had a serious reaction to a previous vaccine dose
- Are currently experiencing moderate or severe illness
- Have previously experienced Guillain-Barré syndrome, particularly following an influenza vaccination
- Are pregnant or planning pregnancy
- Have an immune system condition or use medicines that affect immunity
- Are taking other medicines or receiving other vaccines
CDC identifies severe allergic reaction to a vaccine component or previous dose as a contraindication for inactivated influenza vaccination, while moderate or severe acute illness and a history of Guillain-Barré syndrome within six weeks of an influenza vaccine can be precautions requiring clinical consideration.
VIRIONZA and Egg-Based Manufacturing
The product information supplied states that VIRIONZA is manufactured using influenza virus strains propagated in chicken embryos.
This is relevant for customers with known allergies to components associated with egg-based vaccine production. Current clinical guidance distinguishes between different types of influenza vaccines and individual allergy histories, so patients with a history of severe allergic reactions should discuss vaccination with their healthcare professional rather than making a decision based solely on the product description.
Does VIRIONZA Treat Flu?
No.
VIRIONZA is a preventive vaccine, not a treatment for an existing influenza infection.
If someone already has influenza symptoms such as fever, cough, sore throat, body aches or fatigue, they should seek appropriate medical advice. A healthcare professional can determine whether testing, symptomatic treatment or antiviral treatment is appropriate.
The vaccine is intended to help the body develop an immune response before or during influenza circulation.
Can You Get Influenza After Vaccination?
Yes. Influenza vaccination does not provide absolute protection against every influenza infection.
Possible reasons include:
- Exposure before sufficient immunity develops
- Infection with a virus that differs from vaccine strains
- Individual differences in immune response
- Changes in circulating influenza viruses during the season
Nevertheless, influenza vaccination provides an important preventive measure and can reduce the risk of influenza illness and serious outcomes.
Why Does the Influenza Vaccine Change Every Season?
Influenza viruses are continually changing. Because of this, vaccine manufacturers and public health authorities regularly review which influenza strains should be included in seasonal vaccines.
WHO makes influenza vaccine composition recommendations twice annually once for the Northern Hemisphere and once for the Southern Hemisphere using information from the Global Influenza Surveillance and Response System and other surveillance data.
This means customers should always check the strain composition, season, batch and expiry information on the actual VIRIONZA packaging.
VIRIONZA Storage Conditions
Proper storage is especially important for vaccines.
According to the supplied product information:
Storage temperature: 2°C–8°C
Storage instructions
- Store refrigerated at 2°C–8°C
- Do not freeze
- Protect from sunlight
- Keep the vaccine in its appropriate packaging until use
- Maintain the required cold chain during transportation and storage
If the vaccine has been frozen or stored outside the recommended temperature range, consult a pharmacist or healthcare professional before use.
VIRIONZA Product Specifications
| Product Information | Details |
|---|---|
| Brand | VIRIONZA |
| Generic Name | Influenza Vaccine (Split Virion), Inactivated |
| Dosage Form | Injection |
| Volume | 0.5 mL |
| Hemagglutinin | 15 µg per included strain |
| Presentation | Pre-filled syringe |
| Type | Split-virion, inactivated influenza vaccine |
| Administration | Intramuscular, by healthcare professional |
| Product Age Information | 3 years and above, according to supplied product information |
| Storage | 2°C–8°C |
| Freezing | Do not freeze |
| Packaging | 1 × 0.5 mL pre-filled syringe |
Frequently Asked Questions About VIRIONZA
What is VIRIONZA Influenza Vaccine?
VIRIONZA is a split-virion, inactivated influenza vaccine intended to help prevent seasonal influenza caused by vaccine-related influenza virus strains.
What is the strength of VIRIONZA?
Each 0.5 mL dose contains 15 µg of hemagglutinin from each included influenza strain, according to the supplied product information.
Is VIRIONZA a live vaccine?
No. VIRIONZA is an inactivated influenza vaccine and does not contain live influenza virus.
What age is VIRIONZA suitable for?
The supplied product information states that VIRIONZA is intended for eligible individuals aged 3 years and above. Always follow the approved local product information and healthcare professional advice.
How is VIRIONZA given?
VIRIONZA is administered as an intramuscular injection by a qualified healthcare professional.
Can VIRIONZA be frozen?
No. VIRIONZA should be stored at 2°C–8°C and must not be frozen.
How should VIRIONZA be stored?
Store the vaccine in a refrigerator at 2°C–8°C and protect it from sunlight.
Does VIRIONZA prevent all types of flu?
No vaccine can be expected to protect against every influenza virus. VIRIONZA is designed to provide protection against influenza viruses related to the strains included in the particular vaccine formulation.
Can VIRIONZA be used to treat influenza?
No. VIRIONZA is a preventive vaccine, not a treatment for an existing influenza infection.
Should I consult a doctor before getting VIRIONZA?
Yes. Vaccination should be performed following assessment by an appropriate healthcare professional, particularly if you have allergies, previous vaccine reactions, current illness or other medical conditions.
Buy VIRIONZA Influenza Vaccine Online in Pakistan
VIRIONZA Influenza Vaccine (Split Virion), Inactivated is a refrigerated injectable vaccine intended to help prevent seasonal influenza. Because vaccines require appropriate storage and professional administration, customers should ensure that the product remains within the recommended 2°C–8°C cold-chain conditions and is administered by a qualified healthcare professional.
When purchasing an influenza vaccine online, check the product name, formulation, pack size, batch number, expiry date, storage requirements and strain composition before vaccination.
For the VIRIONZA product supplied here, the listed presentation is 15 µg/0.5 mL in a pre-filled syringe.
Important Medical Disclaimer
This product information is provided for educational and informational purposes and should not replace advice from a qualified doctor, pharmacist or vaccination professional. Vaccine eligibility, dosage, administration, contraindications and recommendations can vary according to the patient's age, medical history, local regulations and the specific influenza season. Always check the manufacturer's current package insert and applicable local healthcare guidance before use.
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