Traditionally, most flu vaccines are produced using hens’ eggs, though the manufacturing process includes steps that reduces the presence of egg protein to a tiny trace. If you have a past history of severe allergic reactions to eggs, then we would recommend choosing one of the alternative vaccines.
Egg-free cell-based vaccines and recombinant vaccines are available that contain no trace of egg protein, so you can still get your annual flu jab safely and without having to worry about possible reactions.
True egg allergy is very rare: we will usually vaccinate people who report no problems when eating egg products such as cakes or egg pasta as the traces of egg protein are miniscule and can be tolerated.
If you are uncertain, talk things over with your doctor, or with the doctor or nurse giving you the flu vaccine. They will be able to advise you on which flu vaccine would be most appropriate for you.
If in any doubt, we would always recommend the cell-based or recombinant vaccines, which are readily available and offers at least the same level of protection. (Egg-free alternatives are available at all our vaccination sessions.)
Our flu vaccines
Flu vaccines are produced using a range of different technologies. Our approach has always been to offer the wisest choice possible.
Supemtek is our premium quadrivalent flu vaccine. It is produced using recombinant technology, which allows an exact molecular match between the vaccine and the surface proteins (antigens) of each of the 4 influenza strains recommended by the World Health Organization, avoiding the risk of mutations that can sometimes occur when viruses are grown in culture. It also contains three times more antigen than both egg-based and cell-based standard-dose vaccines. This increased amount of antigen and the use of recombinant technology provide improved protection against influenza, particularly in those aged 50 and older. In comparison studies with a standard-dose egg-based quadrivalent influenza vaccine, Supemtek reduced the risk of influenza by an additional 30% for adults aged 50 years and older. Supemtek is licensed for adults of all ages over 18. Recombinant technology is likely to replace egg-based vaccine production in future.
Cell-based (egg-free) vaccine
Flucelvax is our egg-free quadrivalent flu vaccine, produced using cell-based technology. Until recently, inactivated flu vaccines could only be produced by growing flu viruses in eggs. The flu viruses used cell-based vaccines are grown in cultured cells of mammalian origin instead of in hens’ eggs, and may provide a closer match to circulating “wild” flu viruses than the viruses grown in eggs. Some studies have shown greater protection against flu-related hospitalisations than standard-dose, egg-based vaccine. Flucelvax is licensed for adults and for children over the age of 2.
FluAd Quadrivalent is a standard-dose, egg-based vaccine that includes an “adjuvant” called MF59. An adjuvant is an ingredient added to a vaccine that helps create a stronger immune response to vaccination. FluAd is licensed for adults aged 65 years and older, who often have a lower protective immune response after flu vaccination compared to younger people.
Nasal spray vaccine
Fluenz Tetra is a nasal spray vaccine containing live attenuated (weakened) influenza A and B virus strains belonging to each of the 4 influenza strains recommended by the World Health Organization. The strains used in the vaccine are “cold-adapted” and cannot survive or multiply at body temperature, so cannot cause infection. However, they do provide a good protective immune response in the nasal passages / upper respiratory tract. The vaccine is sprayed directly into the nose, not given by injection. It is licensed for children aged over 2 but under 18. There have been supply issues with this vaccine in recent years. When not available, appropriate injected vaccines may be used.
Standard quadrivalent vaccines
Standard quadrivalent flu vaccines are suitable for adults and children over the age of six months, and account for the majority of all flu vaccines. They protect against all four of the WHO-recommended strains. Like most flu vaccines, they are manufactured using egg-based technology, and there is long experience in their use.