Some of the views expressed in the following notes on newly approved products should be regarded as tentative, as there may have been limited published data and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. As a result of fuller experience, initial comments may need to be modified. The Committee is prepared to do this. Before new drugs are prescribed, the Committee believes it is important that full information is obtained either from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Intanza (Sanofi Pasteur)
prefilled glass syringes containing 0.1 mL suspension
Approved indication: prevention of seasonal influenza
Australian Medicines Handbook section 20.1
This is the first intradermal influenza vaccine to be approved in Australia. It is an inactivated split virion vaccine containing haemagglutinin from three influenza strains (A/New Caledonia/20/99 (H1N1)-like strain, A/Wisconsin/67/2005 (H3N2)-like strain, B/Malaysia/2506/2004-like strain). The combination of antigens will vary each year depending on the circulating influenza strains.
Unlike the other influenza vaccines, it is administered into the dermal layer of the skin using a 1.5 mm needle. It is thought that after injection, the antigens are taken up by dendritic cells in the dermis and transported to the lymph nodes. Here they are presented to T and B lymphocytes which become activated and undergo clonal expansion.
A trial in 978 adults (aged 18-57) found that immune responses to the intradermal vaccine (9 microgram haemagglutinin per strain in 0.1 mL) were non-inferior to those of an intramuscular vaccine containing the same antigens (15 microgram haemagglutinin per strain in 0.5 mL).1
In another trial in 1107 older adults (aged 60 and over), mean antibody titres to the intradermal vaccine (15 or 21 microgram dose) were superior to an intramuscular comparator vaccine (15 microgram dose). However, injection-site reactions such as erythema were more common with the intradermal vaccine than with the intramuscular vaccine (78% vs 19%). Similarly, more people in the intradermal vaccine group reported induration, swelling and pruritus. Pain was similar between groups.2
A 9 microgram dose will be available for people aged 18-59, and a 15 microgram dose will be available for people aged 60 and over.
manufacturer provided only the product information
References
- Leroux-Roels I, Vets E, Freese R, Seiberling M, Weber F, Salamand C, et al. Seasonal influenza vaccine delivered by intradermal microinjection: a randomised controlled safety and immunogenicity trial in adults. Vaccine 2008;26:6614-9.
- Holland D, Booy R, De Looze F, Eizenberg P, McDonald J, Karrasch J, et al. Intradermal influenza vaccine administered using a new microinjection system produces superior immunogenicity in elderly adults: a randomised controlled trial. J Infect Dis 2008;198:650-8.
The Transparency Score ( 
) is explained in 'New
drugs: transparency', Vol 32 No 3, Aust Prescr 2009;32:80-1.
