tetano
Editor, Senior Moderator
Clin Vaccine Immunol. 2013 Jan 23. [Epub ahead of print]
Unusual patterns of IgG avidity in some young children following two doses of adjuvanted pandemic H1N1(2009) influenza vaccine.
Yam KK, Gupta J, Brewer A, Scheifele DW, Halperin S, Ward BJ; the ?Public Health Agency of Canada?/?Canadian Institute of Health Research? Influenza Research Network (PCIRN) Rapid Trial study #3 (RT-03) investigators.
Source
Department of Experimental Medicine, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
Abstract
Background: During the 2009-2010 H1N1 influenza pandemic, an adjuvanted monovalent vaccine containing ∼25% of the normal antigen dose and AS03 adjuvant was widely used in Canada. This vaccine was found to be well-tolerated and immunogenic in young children (Scheifele DW et.al. 2011. Pediatr.Infect.Dis.J. 30:402-407.). Here we report additional analyses to further characterize the humoral response to this vaccine.Methods: We measured standard hemagglutination inhibition (HAI) and microneutralization (MN) titres as well as influenza-specific IgG avidity and subclass distribution by ELISA in 73 subjects; sera were collected before (day 0) and 3 weeks after each dose of vaccine (days 21 and 42).Results: Most children (55/73) had undetectable HAI and MN titers at day 0 (presumed antigen-na?ve) and mounted good responses at days 21 and 42. The majority of these children (43/55) had the expected pattern of an increasing IgG avidity index (AI) after each dose of vaccine (not detected; ND, 0.30, 2.97; at days 0, 21 and 42, respectively). Avidity responses in the remaining children (12/55) were quite different with AI increasing abruptly after the first dose, then declining after the second dose of vaccine (ND, 8.83, 7.15). These children also had higher concentrations of influenza-specific IgG1 and IgG3 antibodies at day 21.Conclusions: Although antibody titers were similar, some antigen-na?ve children demonstrated an unusual pattern of avidity maturation following two immunizations with AS03-adjuvanted, low-dose influenza vaccine. These data suggest the presence of subtle differences in the quality of the antibodies produced by some subjects in response to this vaccine.
PMID:
23345582
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23345582
Unusual patterns of IgG avidity in some young children following two doses of adjuvanted pandemic H1N1(2009) influenza vaccine.
Yam KK, Gupta J, Brewer A, Scheifele DW, Halperin S, Ward BJ; the ?Public Health Agency of Canada?/?Canadian Institute of Health Research? Influenza Research Network (PCIRN) Rapid Trial study #3 (RT-03) investigators.
Source
Department of Experimental Medicine, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
Abstract
Background: During the 2009-2010 H1N1 influenza pandemic, an adjuvanted monovalent vaccine containing ∼25% of the normal antigen dose and AS03 adjuvant was widely used in Canada. This vaccine was found to be well-tolerated and immunogenic in young children (Scheifele DW et.al. 2011. Pediatr.Infect.Dis.J. 30:402-407.). Here we report additional analyses to further characterize the humoral response to this vaccine.Methods: We measured standard hemagglutination inhibition (HAI) and microneutralization (MN) titres as well as influenza-specific IgG avidity and subclass distribution by ELISA in 73 subjects; sera were collected before (day 0) and 3 weeks after each dose of vaccine (days 21 and 42).Results: Most children (55/73) had undetectable HAI and MN titers at day 0 (presumed antigen-na?ve) and mounted good responses at days 21 and 42. The majority of these children (43/55) had the expected pattern of an increasing IgG avidity index (AI) after each dose of vaccine (not detected; ND, 0.30, 2.97; at days 0, 21 and 42, respectively). Avidity responses in the remaining children (12/55) were quite different with AI increasing abruptly after the first dose, then declining after the second dose of vaccine (ND, 8.83, 7.15). These children also had higher concentrations of influenza-specific IgG1 and IgG3 antibodies at day 21.Conclusions: Although antibody titers were similar, some antigen-na?ve children demonstrated an unusual pattern of avidity maturation following two immunizations with AS03-adjuvanted, low-dose influenza vaccine. These data suggest the presence of subtle differences in the quality of the antibodies produced by some subjects in response to this vaccine.
PMID:
23345582
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23345582