In a clinical trial, immunization with the licensed influenza vaccine containing squalene did not affect the frequency or titre of anti-squalene antibodies.

In August, follow-up testing of paired-serum samples found a fourfold rise in neutralization antibody titer for H5N1, a test result which meets the WHO criteria for laboratory confirmation.

The resulting "trivalent" vaccine provokes the patient's immune system into producing antibodies, and that primes it for an attack by the worrying strains of flu.