Influenza standardisation

Standardisation in the area of influenza vaccines is an important aspect of NIBSC’s influenza work.

We generate reference reagents – standards – for both seasonal and (pre)pandemic vaccines. These are used worldwide by manufacturers and control laboratories and are indispensable for the release of vaccine onto the market.

We also have an interest in standardisation of influenza serology. The immunogenicity of influenza vaccines in humans is assessed using three main methods:

• haemagglutination inhibition assay (HI)
• virus neutralisation assay (VN)
• single radial haemolysis assay (SRH)

The most important – and most widely used – of these is the HI assay. Experience over many years has shown that these methods are variable between laboratories, with results varying sometimes by large amounts. This makes comparison of studies conducted in different laboratories difficult.

One way to reduce variability between laboratories is to use a biological standard.

To achieve this we have generated World Health Organisation (WHO) International Standards for antibodies to influenza virus. We found that use of the first of these, directed against avian A(H5N1) viruses of clade 1, reduced between-laboratory variability by around 50%. Subsequent International Standards for antibody against pandemic A(H1N1) virus were similarly effective in reducing variability.

NIBSC is an active member of the Consortium for the Standardisation of Influenza Seroepidemiology (CONSISE).

This consortium aims to standardise influenza seroepidemiology. Its laboratory group is working on the harmonisation of assay protocols, the evaluation and use of antibody standards and the establishment of an international network of serology laboratories.