Multi-factorial association of serological response to the A(H1N1)pdm09 influenza strain as function of age, NSSN and total, naïve and influenza specific activated CD4⁺ T cells in the pilot study.

Abstract

<p>A) High CD4⁺ T cell counts give rise to sero-protection (HAI>40) irrespective of age or NSSN. Age still plays a role in vaccinees with NSSN = 3 and low CD4⁺ T cell counts, where 80% of old (red circles) versus only 20% of young (blue circles) are non-protected (p = 0.01). The same trend (p = NS) is also seen for NSSN = 2 (triangles) with low CD4⁺ T cell counts, albeit with better response than NSSN = 3. The only 2 donors with NSSN = 1 are sero-protected even if they are old and have low CD4⁺ T cell counts. B) Naive CD4⁺ T cell counts show a trend (p = NS) for a positive association with serological response in all age groups (NSSN = 2–3). C) Influenza specific activated CD4⁺CD40L⁺ T cell counts are not associated with serological response in any of the age groups (NSSN = 2–3).</p