tetano
Editor, Senior Moderator
Vaccine. 2018 Apr 18. pii: S0264-410X(18)30486-9. doi: 10.1016/j.vaccine.2018.04.017. [Epub ahead of print]
[h=1]Responses to live attenuated influenza vaccine in children vaccinated previously with Pandemrix (ASO3[SUB]B[/SUB] adjuvanted pandemic A/H1N1pdm09).[/h] H?schler K[SUP]1[/SUP], Southern J[SUP]2[/SUP], Thompson C[SUP]2[/SUP], Warburton F[SUP]2[/SUP], Andrews NJ[SUP]2[/SUP], Miller E[SUP]2[/SUP], Zambon M[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We report a phase III/IV open-label study on the immunogenicity of a single dose of a Live Attenuated Influenza Vaccine (LAIV) (Fluenz?) in children na?ve to, or in previous receipt of, AS03[SUB]B[/SUB] adjuvanted A/H1N1pdm09 influenza vaccine (Pandemrix?), to investigate whether early exposure to an adjuvanted subunit influenza vaccine impacts on subsequent response to quadrivalent LAIV (qLAIV).
[h=4]METHOD AND FINDINGS:[/h] Eligible children were enrolled to receive qLAIV and stratified according to previous Pandemrix? vaccination. Functional antibody for the vaccine strains were analysed using Haemagglutination Inhibition (HAI); in addition antibodies to the A/H1N1pdm09 strain were measured by Neuraminidase Antibody Inhibition (NAI) and neutralisation assays. Fourfold titre increases by HAI were observed for 39% (95% confidence interval 33-46%) and 43% (37-51%) of subjects for the two influenza B vaccine strains and 8% (5-13%) for the A/H3N2 strain with no significant differences between the Pandemrix? na?ve or previously vaccinated groups in antibody tites pre- or post-vaccination or seroconversion rates. In both groups, the response to the qLAIV A/H1N1pdm09 component was barely detectable, overall HAI seroconversion rate 1.8% (0.5-4.7%). Previous receipt of Pandemrix? was associated with significantly higher levels of A/H1N1pdm09 neutralising antibody, but decreased NAI titres pre-vaccination, with the differences maintained post-vaccination.
[h=4]CONCLUSION:[/h] Previous receipt of Pandemrix? has had a significant impact on the influenza immune status of children several years later. Higher levels of neutralising antibody to A/H1N1pdm09 pre- and post-vaccination, but significantly lower levels of antibody to NA, were observed compared with Pandemrix?-na?ve children, while responses to influenza B and A/H3N2 and antibody levels prior to vaccination were similar in both groups. This suggests that early vaccination with a powerful adjuvant maintains functional immunity for several years, which prevents natural infection. Alternatively, the AS03[SUB]B[/SUB] adjuvant may have re-directed the immune response, with focus towards viral HA and away from viral NA.
Crown Copyright ? 2018. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Childhood; Cross-reactive effects; Influenza; Oil-in-water adjuvant; Vaccine
PMID: 29680198 DOI: 10.1016/j.vaccine.2018.04.017
[h=1]Responses to live attenuated influenza vaccine in children vaccinated previously with Pandemrix (ASO3[SUB]B[/SUB] adjuvanted pandemic A/H1N1pdm09).[/h] H?schler K[SUP]1[/SUP], Southern J[SUP]2[/SUP], Thompson C[SUP]2[/SUP], Warburton F[SUP]2[/SUP], Andrews NJ[SUP]2[/SUP], Miller E[SUP]2[/SUP], Zambon M[SUP]3[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] We report a phase III/IV open-label study on the immunogenicity of a single dose of a Live Attenuated Influenza Vaccine (LAIV) (Fluenz?) in children na?ve to, or in previous receipt of, AS03[SUB]B[/SUB] adjuvanted A/H1N1pdm09 influenza vaccine (Pandemrix?), to investigate whether early exposure to an adjuvanted subunit influenza vaccine impacts on subsequent response to quadrivalent LAIV (qLAIV).
[h=4]METHOD AND FINDINGS:[/h] Eligible children were enrolled to receive qLAIV and stratified according to previous Pandemrix? vaccination. Functional antibody for the vaccine strains were analysed using Haemagglutination Inhibition (HAI); in addition antibodies to the A/H1N1pdm09 strain were measured by Neuraminidase Antibody Inhibition (NAI) and neutralisation assays. Fourfold titre increases by HAI were observed for 39% (95% confidence interval 33-46%) and 43% (37-51%) of subjects for the two influenza B vaccine strains and 8% (5-13%) for the A/H3N2 strain with no significant differences between the Pandemrix? na?ve or previously vaccinated groups in antibody tites pre- or post-vaccination or seroconversion rates. In both groups, the response to the qLAIV A/H1N1pdm09 component was barely detectable, overall HAI seroconversion rate 1.8% (0.5-4.7%). Previous receipt of Pandemrix? was associated with significantly higher levels of A/H1N1pdm09 neutralising antibody, but decreased NAI titres pre-vaccination, with the differences maintained post-vaccination.
[h=4]CONCLUSION:[/h] Previous receipt of Pandemrix? has had a significant impact on the influenza immune status of children several years later. Higher levels of neutralising antibody to A/H1N1pdm09 pre- and post-vaccination, but significantly lower levels of antibody to NA, were observed compared with Pandemrix?-na?ve children, while responses to influenza B and A/H3N2 and antibody levels prior to vaccination were similar in both groups. This suggests that early vaccination with a powerful adjuvant maintains functional immunity for several years, which prevents natural infection. Alternatively, the AS03[SUB]B[/SUB] adjuvant may have re-directed the immune response, with focus towards viral HA and away from viral NA.
Crown Copyright ? 2018. Published by Elsevier Ltd. All rights reserved.
[h=4]KEYWORDS:[/h] Childhood; Cross-reactive effects; Influenza; Oil-in-water adjuvant; Vaccine
PMID: 29680198 DOI: 10.1016/j.vaccine.2018.04.017