Healthcare Professional Site Prescribing Information | Patient website | Mylan | Log in




1) Administration With Other Vaccines

Influvac® and Imuvac® are inactivated vaccines. They can be given at the same time as other vaccines. Immunisation should be carried out on separate limbs. Adverse reactions may be intensified.1

2) Adverse Effects

All adverse events to Influvac® or Imuvac® should be reported to Mylan by phone on 0800 121 8267.

or by email to:

To view a full list of adverse effects, please see Influvac® and Imuvac® SPCs section 4.8 (

3) Antibiotics

We are not aware of any interactions between influenza vaccine and antibiotics.

The vaccine may contain traces of gentamicin. This antibiotic is used during the manufacturing process.

Our SPC states that use of our vaccines in patients hypersensitive to any of the active substances or excipients including gentamicin is contraindicated.1

We are not aware of any cross-reactivity between penicillin and gentamicin. Therefore patients sensitive to penicillin should be able to receive influenza vaccine, provided no other contraindications exist.

4) Breast Feeding

Influvac® and Imuvac® may be used during breastfeeding, provided no other contraindications exist.1

5) Egg Protein Content (Ovalbumin)

Can Influvac® or Imuvac® be given to patients hypersensitive (allergic) to chicken protein and eggs?

Influvac® and Imuvac® should not be given to patients hypersensitive (allergic) to chicken protein or eggs. The ovalbumin content of the vaccine is not more than 0.1mcg per 0.5 ml dose (i.e. 0.2 mcg per ml).1

6) Children

Can Influvac® and Imuvac® be used in young children? Yes, in children from 6 months of age.2 See below for details.
Administration of Influvac® and Imuvac® in children
Children less than 6 months: No experience exists of Influvac® and Imuvac® being used in children under 6 months of age.
Children from 6 months to 35 months: Clinical data are limited. Dosages of 0.25 ml or 0.5ml may be given. The dose given should be in accordance with existing national recommendations. The Joint Committee on Vaccination and Immunisation has advised that where these alternative doses are indicated in the SPC, the 0.5ml dose of intramuscular inactivated influenza vaccine should be given to infants aged six months or older and young children because there is evidence that this dose is effective in young children.1

Adults and children from 36 months: 0.5ml Immunisation should be intramuscular or deep subcutaneous injection.

The UK Department of Health (Green Book) recommends that children aged 6 months to less than 9 years who have not received the intramuscular flu vaccine before should receive a second dose of vaccine at least four weeks later.

Administration of 0.25ml dose of Influvac® and Imuvac®2

The Influvac® and Imuvac® 0.5ml syringe is not graduated. For administration of a 0.25ml dose from a syringe:

Eject the air from the syringe.

Push the front side of the plunger exactly to the edge of the mark so that half of the volume is eliminated; a volume of 0.25 ml of the vaccine remains in the syringe, suitable for administration.

7) Interchangeable vaccines

The inactivated trivalent seasonal flu vaccines are interchangeable, as quoted in the Green Book, Chapter 19 (updated August 2015)1.

Therefore if a child needs two doses of inactivated seasonal flu vaccine four weeks apart, then two different brands of inactivated seasonal flu vaccines could be used.

8) Constituents

The constituents of Influvac® and Imuvac® for the 2017/2018 season as recommended by the World Health Organization are as follows:

Active constituents Influvac® and Imuvac®:

  • A/Michigan/45/2015 (H1N1)pdm09-like virus;
  • A/Hong Kong/4801/2014 (H3N2)-like virus;
  • B/Brisbane/60/2008-like virus.

Other constituents: Influvac® and Imuvac®

  • Potassium dihydrogen phosphate
  • Disodium phosphate dihydrate
  • Sodium chloride
  • Potassium chloride
  • Calcium chloride dihydrate
  • Magnesium chloride hexahydrate
  • Water for injections

Residue or traces of:

  • Formaldehyde
  • Cetyltrimethylammonium bromide
  • Ovalbumin
  • Chicken proteins
  • Polysorbate 80
  • Gentamicin

9) Contraindications

Which patients should not be vaccinated?

Allergy to eggs or chicken protein Patients hypersensitive (allergic) to eggs or chicken protein should not be vaccinated with Influvac® and Imuvac®.

Allergy to gentamicin or any other constituent of the vaccine. As Influvac® and Imuvac® may contain minimal amounts of gentamicin, they should not be used in patients hypersensitive to this antibiotic. Patients who are allergic to any of the ingredients or to any of the components that could be present in trace amounts, should not receive Influvac® and Imuvac®. Please also see 8) Constituents.

Febrile Illness: Vaccination should be postponed in patients with febrile illness or acute infection.

10) Damaged Vaccine Syringes

What should I do if Influvac® or Imuvac® syringes arrive damaged?

Please email, enclosing a short summary of the problem, your name and address and account number. Please also say whether you would like credit or the stock replaced.

Back to Top

11) Expiry Date

Can Influvac® or Imuvac® be used beyond its expiry date?

The shelf-life is 12 months provided that the vaccine has been stored correctly. Use of any vaccine after its expiry date is not recommended.

In addition the vaccines contain appropriate quantities of the A and B virus strains that are recommended by the World Health Organization. These strains vary from year to year and therefore vaccines from previous years may not contain the current recommended virus strains.

Please also see 19) Storage and Stability

12) Flu

Can Influvac® or Imuvac® cause the flu?

Influvac® and Imuvac® contain inactivated viral components and thus cannot cause flu.

Flu-like symptoms can be caused by many respiratory infections (including the common cold) and Influvac® and Imuvac® will not prevent these.

The incubation period for the flu is a few days, so if a patient is exposed to the flu immediately before or after vaccination, the illness could still develop.

13) Frequency Of Vaccination

Is vaccination with Influvac® or Imuvac® needed each year?

The vaccination is needed each year for optimal protection against flu.

Annual vaccination for those in the At Risk Groups is required because the flu virus can vary each year. Therefore the immunity induced by previous vaccination will not give optimum protection to new virus strains.

Each year the World Health Organization (WHO) recommends which antigens should be included in the flu vaccines.

Influvac® and Imuvac® comply with the WHO recommendations.

14) Immunity

How soon after vaccination will protection against flu be achieved?

Protective antibody levels are achieved within 2-3 weeks. The duration of immunity varies but is usually 6-12 months. The ideal time for vaccination is between September and early November. Protection afforded by the vaccine is thought to last for at least one flu season. However, as the level of protection provided in subsequent seasons is likely to reduce and there may be changes to the circulating strains from one season to the next, annual re-vaccination is important.1
Flu-like symptoms can be caused by many respiratory infections (including the common cold) and Influvac® and Imuvac® will not prevent these.

15) Latex

Does Influvac® or Imuvac® contain latex?


Influvac® and Imuvac® are contained in pre-filled syringes that have a rubber component. This is made only from synthetic rubber, and not latex. The needle guard contains no latex. It is made from polypropylene mixed with 1-2% titanium oxide dye.


During production, contact with rubber may occur (e.g. rubber rings are used to close off containers during production). Direct contact of our product should not occur, but cannot be excluded.

Back to Top

16) Launch

When were Influvac® and Imuvac® first launched?

Influvac® was first launched in 1962.

Imuvac® was first launched in 2006.

17) What other vaccines are available from Mylan?

Aside from Influvac® and Imuvac® no other vaccines are produced by Mylan.

18) Pregnancy

The pregnancy section in the UK SPC, section 4.6, states:

“Inactivated influenza vaccines can be used in all stages of pregnancy. Larger datasets on safety are available for the second and third trimester, compared with the first trimester; however, data from worldwide use of influenza vaccine do not indicate any adverse foetal and maternal outcomes attributable to the vaccine”. The Influvac®/Imuvac® SPCs state that its use should be based on official recommendations. (section 4.1)1

UK Recommendations
The latest advice from the Department of Health UK is provided below:
All pregnant women are recommended to receive the inactivated flu vaccine irrespective of their stage of pregnancy.2

A review of studies on the safety of flu vaccine in pregnancy concluded that inactivated seasonal flu vaccine can be safely and effectively administered during any trimester of pregnancy and that no study to date has demonstrated an increased risk of either maternal complications or adverse foetal outcomes associated with inactivated flu vaccine.2

19) Storage And Stability

How should Influvac® or Imuvac® be stored?

The optimum temperature for storage is between 2-8oC, for a period no longer than twelve months.

Storage out of the fridge

Influvac® and Imuvac® should always be stored at 2-8oC, but in the event of accidental storage at higher temperatures, please contact the Influvac Customer Care Centre on 0800 358 7468.

Storage below 2oC

In the event of accidental storage below 2oC, please contact the Influvac Customer Care Centre on 0800 358 7468.

The vaccines should not be frozen.
Protect from light.

20) Subunit Vaccine

What is meant by a subunit vaccine?

The different types of inactivated flu vaccine are as follows:

  • Whole Virus Vaccines: The whole virus is used to induce immunity
  • Split-Virion Vaccines: The protein coat of the virus is split away from the virus core and is used to induce immunity
  • Sub-Unit Vaccines: The protein coat is further broken down and only the 'H' and 'N' antigens are used.

21) Vaccine Strains

Influvac® and Imuvac® contain appropriate quantities of the A and B virus strains that are recommended by the World Health Organization. These strains vary from year to year. The strains that are present in Influvac® and Imuvac® for the 2017/2018 season will be:

  • A/Michigan/45/2015 (H1N1)pdm09-like virus;
  • A/Hong Kong/4801/2014 (H3N2)-like virus;
  • B/Brisbane/60/2008-like virus.

22) Influvac® and Imuvac® and Thiomersal

Influvac® and Imuvac® are thiomersal free.

Mylan Logo is owned by Mylan Pharmaceuticals Company

For more information visit

©2017 Mylan N.V. All Rights Reserved.