tetano
Editor, Senior Moderator
Vaccine. 2014 Nov 28;32(50):6798-804. doi: 10.1016/j.vaccine.2014.09.070. Epub 2014 Oct 16.
Live attenuated H7N7 influenza vaccine primes for a vigorous antibody response to inactivated H7N7 influenza vaccine.
Babu TM1, Levine M2, Fitzgerald T1, Luke C3, Sangster MY4, Jin H5, Topham D4, Katz J2, Treanor J6, Subbarao K3.
Author information
Abstract
BACKGROUND:
H7 influenza viruses have emerged as potential pandemic threat. We evaluated the safety and immunogenicity of two candidate H7 pandemic live attenuated influenza vaccines (pLAIV) and their ability to prime for responses to an unadjuvanted H7 pandemic inactivated influenza vaccine (pIIV).
METHODS:
Healthy seronegative adults received two doses of A/Netherlands/219/03 (H7N7) or one dose of A/chicken/British Columbia/CN-6/04 (H7N3) pLAIV all given as 10(7.5) 50% tissue culture infective doses (TCID50) intranasally. A subset of subjects received one 45μg dose of H7N7 pIIV containing the A/Mallard/Netherlands/12/2000 HA intramuscularly 18-24 months after pLAIV. Viral shedding was assessed by culture and real-time polymerase chain reaction (rRT-PCR), B cell responses following pLAIV were evaluated by ELISPOT and flow cytometry. Serum antibody was assessed by hemagglutination-inhibition (HAI), microneutralization (MN) and ELISA assays after each vaccine.
RESULTS:
Serum HAI or MN responses were not detected in any subject following one or two doses of either H7 pLAIV, although some subjects had detectable H7 specific B cells after vaccination. However, 10/13 subjects primed with two doses of H7N7 pLAIV responded to a subsequent dose of the homologous H7N7 pIIV with high titer HAI and MN antibody that cross-reacted with both North American and Eurasian lineage H7 viruses, including H7N9. In contrast, na?ve subjects and recipients of a single dose of the mismatched H7N3 pLAIV did not develop HAI or MN antibody after pIIV.
CONCLUSIONS:
While pLAIVs did not elicit detectable serum MN or HAI antibody, strain-specific pLAIV priming established long term immune memory that was cross-reactive with other H7 influenza strains. Understanding the mechanisms underlying priming by pLAIV may aid in pandemic vaccine development.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
H7N7; Influenza; Live attenuated vaccine; Pandemic; Priming
PMID:
25446831
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/pubmed/25446831
Live attenuated H7N7 influenza vaccine primes for a vigorous antibody response to inactivated H7N7 influenza vaccine.
Babu TM1, Levine M2, Fitzgerald T1, Luke C3, Sangster MY4, Jin H5, Topham D4, Katz J2, Treanor J6, Subbarao K3.
Author information
Abstract
BACKGROUND:
H7 influenza viruses have emerged as potential pandemic threat. We evaluated the safety and immunogenicity of two candidate H7 pandemic live attenuated influenza vaccines (pLAIV) and their ability to prime for responses to an unadjuvanted H7 pandemic inactivated influenza vaccine (pIIV).
METHODS:
Healthy seronegative adults received two doses of A/Netherlands/219/03 (H7N7) or one dose of A/chicken/British Columbia/CN-6/04 (H7N3) pLAIV all given as 10(7.5) 50% tissue culture infective doses (TCID50) intranasally. A subset of subjects received one 45μg dose of H7N7 pIIV containing the A/Mallard/Netherlands/12/2000 HA intramuscularly 18-24 months after pLAIV. Viral shedding was assessed by culture and real-time polymerase chain reaction (rRT-PCR), B cell responses following pLAIV were evaluated by ELISPOT and flow cytometry. Serum antibody was assessed by hemagglutination-inhibition (HAI), microneutralization (MN) and ELISA assays after each vaccine.
RESULTS:
Serum HAI or MN responses were not detected in any subject following one or two doses of either H7 pLAIV, although some subjects had detectable H7 specific B cells after vaccination. However, 10/13 subjects primed with two doses of H7N7 pLAIV responded to a subsequent dose of the homologous H7N7 pIIV with high titer HAI and MN antibody that cross-reacted with both North American and Eurasian lineage H7 viruses, including H7N9. In contrast, na?ve subjects and recipients of a single dose of the mismatched H7N3 pLAIV did not develop HAI or MN antibody after pIIV.
CONCLUSIONS:
While pLAIVs did not elicit detectable serum MN or HAI antibody, strain-specific pLAIV priming established long term immune memory that was cross-reactive with other H7 influenza strains. Understanding the mechanisms underlying priming by pLAIV may aid in pandemic vaccine development.
Copyright ? 2014. Published by Elsevier Ltd.
KEYWORDS:
H7N7; Influenza; Live attenuated vaccine; Pandemic; Priming
PMID:
25446831
[PubMed - in process]
http://www.ncbi.nlm.nih.gov/pubmed/25446831