A reduced immune response was previously observed in elderly people, as compared with younger adults, following influenza vaccination. Because the number of elderly persons is rapidly increasing in the world, understanding factors influencing their immune response to influenza vaccines is of considerable interest in order to devise more immunogenic vaccines. Our study examined the antibody response comparing haemagglutination inhibition antibody titers in sera collected before and 30 days after vaccination, in 2,630 elderly institutionalized people after vaccination with commercially available trivalent inactivated influenza vaccines over a period of 20 winters (between 1993-94 and 2014-2015). The elderly studied were grouped into two age groups, elderly (60-84 years) and very elderly (≥85 years), and the possible influence of variables like sex, change of vaccine antigens, or type of vaccine used was analysed. The response against the three vaccine antigens observed in the two age groups was in most instances comparable. Higher responses were found in female as compared with male subjects. The presence of a novel antigen in the vaccine composition induced higher responses as compared with years with unchanged vaccine composition. Comparing the different vaccines used, the immune response observed after intradermal and MF59-adjuvanted vaccines was higher than after split and subunit vaccines.
Factors influencing humoral immune response after influenza vaccination in elderly and very elderly subjects
CAMILLONI, Barbara;NUNZI, Emilia;BIANCHINI, CINZIA;IORIO, Anna Maria
2016
Abstract
A reduced immune response was previously observed in elderly people, as compared with younger adults, following influenza vaccination. Because the number of elderly persons is rapidly increasing in the world, understanding factors influencing their immune response to influenza vaccines is of considerable interest in order to devise more immunogenic vaccines. Our study examined the antibody response comparing haemagglutination inhibition antibody titers in sera collected before and 30 days after vaccination, in 2,630 elderly institutionalized people after vaccination with commercially available trivalent inactivated influenza vaccines over a period of 20 winters (between 1993-94 and 2014-2015). The elderly studied were grouped into two age groups, elderly (60-84 years) and very elderly (≥85 years), and the possible influence of variables like sex, change of vaccine antigens, or type of vaccine used was analysed. The response against the three vaccine antigens observed in the two age groups was in most instances comparable. Higher responses were found in female as compared with male subjects. The presence of a novel antigen in the vaccine composition induced higher responses as compared with years with unchanged vaccine composition. Comparing the different vaccines used, the immune response observed after intradermal and MF59-adjuvanted vaccines was higher than after split and subunit vaccines.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
