BioMed Protection

 

H3N2 vaccine efficacy tool

The overall effectiveness of the 2017 seasonal influenza vaccine in Southern Hemisphere was reduced due to low efficacy measured against influenza A(H3N2) – the predominant subtype. Recently, informational analysis showed that viruses circulating in Australia and US in 2017 are different (https://f1000research.com/articles/6-2067/v1) suggesting that we might have very different vaccine efficacy in these two countries during this flu season.

The vaccine efficacy is also changing during the flu season due to genetic mutations/virus evolution. The UTMB/BioPro bioinformatics tool gives possibility for continuing, real-time assessment of the vaccine efficacy for A(H3N2) strains using HA sequences that become available for analysis during the flu season. This assessment is based on the novel ISM-based (Informational Spectrum Method) phylogenetic analysis, which allows us to study the virus evolution based on biological/functional changes in the HA instead of focusing on structural properties of proteins (for details visit Biomed Protection).

Vaccine sensitive viruses in the ISM-phylogenetic tree are clustered together with the vaccine virus (VRES). Viruses outside of this cluster are predicted to be more resistant to the current vaccine (VNONRES). Ratio between these two groups of viruses (VRES/VNONRES) correlates with the vaccine efficacy. It is postulated, based on the historical data for the vaccine efficacy against A(H3N2) viruses, that the ratio VRES/VNONRES > 1 corresponds to effectiveness of 35% or higher.

H3N2 July-September 2017
Viruses collected in US between July and September which represent precursors for the flu season 2017/2018. (VRES/VNONRES = 2.39)

H3N2 October 2017
H3N2 October 2017 (VRES/VNONRES = 3.49)

H3N2 November 2017
H3N2 November 2017 (VRES/VNONRES = 5.82)

H3N2 December 2017
H3N2 December 2017 (VRES/VNONRES = 5.80)

Generate ISM-based phylogenetic tree


Input additional sequences (max 100)
 

Example

You can see the valid input format in the next example. Click on the button and example data will fill the box in the form above.

  •     Set of three sequences.
     
    Clear all fields.