tetano
Editor, Senior Moderator
Vaccine. 2019 Apr 4. pii: S0264-410X(19)30420-7. doi: 10.1016/j.vaccine.2019.03.071. [Epub ahead of print]
[h=1]Safety and immunogenicity of an 8 year interval heterologous prime-boost influenza A/H7N7-H7N9 vaccination.[/h] El Sahly HM[SUP]1[/SUP], Atmar RL[SUP]2[/SUP], Patel SM[SUP]2[/SUP], Bellamy A[SUP]3[/SUP], Liu L[SUP]4[/SUP], Hong W[SUP]4[/SUP], Zhu H[SUP]4[/SUP], Guan Y[SUP]5[/SUP], Keitel WA[SUP]6[/SUP]; DMID 13-0033 Vaccine Study Group.
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza A/H7N9 viruses are undergoing antigenic drift since their emergence in 2013, and vaccination strategies are needed for pandemic preparedness. Two doses of adjuvanted monovalent inactivated influenza A/H7N9 vaccine (IIV1 A/H7N9) are needed for optimal serological responses. However, administering 2 doses in a pandemic setting might be challenging. We evaluated the immunogenicity of "boosting" with IIV1 A/H7N9 in subjects "primed" 8 years previously with IIV1 A/H7N7.
[h=4]METHODS:[/h] We administered 1 booster dose containing 45 mcg of IIV1 A/H7N9 hemagglutinin to 17 recipients of 2 prior doses of IIV1 A/H7N7, and to 10 influenza A/H7-na?ve subjects. We tested their post-boosting sera for antibodies (Ab) against homologous influenza A/H7N9 using a hemagglutination inhibition assay; and compared their Ab titers to those in stored sera from recipients of AS03-adjuvanted IIV1 A/H7N9 against 9 strains of influenza A/H7N9 viruses.
[h=4]RESULTS:[/h] The percentage of subjects with Ab titers ≥40 on Days 9 and 29 post boosting, respectively, was 65% and 41% in primed subjects and 10% and 0% in unprimed subjects. The Ab titers in recipients of AS03-adjuvanted IIV1 A/H7N9 were higher than those in the prime-boost group against a panel of influenza A/H7N9 viruses, except for 2 highly pathogenic strains.
[h=4]CONCLUSIONS:[/h] Priming with IIV1 A/H7 results in serological responses following a delayed boost with 1 dose of unadjuvanted IIV1 A/H7N9, despite lack of antibody response after the prime. Optimizing prime-boost approaches would benefit pandemic preparedness. ClinicalTrials.gov identifier: NCT02586792.
Copyright ? 2019. Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Avian; Influenza; Influenza A/H7N9; Pandemic; Prime-boost; Vaccines
PMID: 30955980 DOI: 10.1016/j.vaccine.2019.03.071
[h=1]Safety and immunogenicity of an 8 year interval heterologous prime-boost influenza A/H7N7-H7N9 vaccination.[/h] El Sahly HM[SUP]1[/SUP], Atmar RL[SUP]2[/SUP], Patel SM[SUP]2[/SUP], Bellamy A[SUP]3[/SUP], Liu L[SUP]4[/SUP], Hong W[SUP]4[/SUP], Zhu H[SUP]4[/SUP], Guan Y[SUP]5[/SUP], Keitel WA[SUP]6[/SUP]; DMID 13-0033 Vaccine Study Group.
[h=3]Author information[/h]
[h=3]Abstract[/h] [h=4]BACKGROUND:[/h] Influenza A/H7N9 viruses are undergoing antigenic drift since their emergence in 2013, and vaccination strategies are needed for pandemic preparedness. Two doses of adjuvanted monovalent inactivated influenza A/H7N9 vaccine (IIV1 A/H7N9) are needed for optimal serological responses. However, administering 2 doses in a pandemic setting might be challenging. We evaluated the immunogenicity of "boosting" with IIV1 A/H7N9 in subjects "primed" 8 years previously with IIV1 A/H7N7.
[h=4]METHODS:[/h] We administered 1 booster dose containing 45 mcg of IIV1 A/H7N9 hemagglutinin to 17 recipients of 2 prior doses of IIV1 A/H7N7, and to 10 influenza A/H7-na?ve subjects. We tested their post-boosting sera for antibodies (Ab) against homologous influenza A/H7N9 using a hemagglutination inhibition assay; and compared their Ab titers to those in stored sera from recipients of AS03-adjuvanted IIV1 A/H7N9 against 9 strains of influenza A/H7N9 viruses.
[h=4]RESULTS:[/h] The percentage of subjects with Ab titers ≥40 on Days 9 and 29 post boosting, respectively, was 65% and 41% in primed subjects and 10% and 0% in unprimed subjects. The Ab titers in recipients of AS03-adjuvanted IIV1 A/H7N9 were higher than those in the prime-boost group against a panel of influenza A/H7N9 viruses, except for 2 highly pathogenic strains.
[h=4]CONCLUSIONS:[/h] Priming with IIV1 A/H7 results in serological responses following a delayed boost with 1 dose of unadjuvanted IIV1 A/H7N9, despite lack of antibody response after the prime. Optimizing prime-boost approaches would benefit pandemic preparedness. ClinicalTrials.gov identifier: NCT02586792.
Copyright ? 2019. Published by Elsevier Ltd.
[h=4]KEYWORDS:[/h] Avian; Influenza; Influenza A/H7N9; Pandemic; Prime-boost; Vaccines
PMID: 30955980 DOI: 10.1016/j.vaccine.2019.03.071