Booster vaccination in the elderly: Their success depends on the vaccine type applied earlier in life as well as on pre-vaccination antibody titers. - Kaml,M.; Weiskirchner,I.; Keller,M.; Luft,T.; Hoster,E.; Hasford,J.; Young,L.; Bartlett,B.; Neuner,C.; Fischer,K.H.; Neuman,B.; Würzner,R.; et al. (Vaccine, 2006)