RT Journal Article SR Electronic(1) A1 Ikonen, N A1 Strengell, M A1 Kinnunen, L A1 Ă–sterlund, P A1 Pirhonen, J A1 Broman, M A1 Davidkin, I A1 Ziegler, T A1 Julkunen, I YR 2010 T1 High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland JF Eurosurveillance VO 15 IS 5 SP 19478 OP DO https://doi.org/10.2807/ese.15.05.19478-en UL https://www.eurosurveillance.org/content/10.2807/ese.15.05.19478-en