Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2016/06/flu-scan-jun-09-2016
Flu Scan for Jun 09, 2016
H7N9 vaccine antibodies; Avian flu cases in China
Filed Under:
Avian Influenza (Bird Flu); Influenza Vaccines; H7N9 Avian Influenza [h=3]Study: Non-neutralizing antibodies may play a role in flu vaccine protection[/h] Non-neutralizing, cross-reactive antibodies may play a role in fostering protective immunity following H7N9 avian flu vaccination and are likely missed by traditional vaccine immunogenicity tests, according to a study yesterday in Cell Host & Microbe.
H7N9 vaccine development has been stymied by the vaccine's questionable ability to spur a potent immune response. To identify the protective potential of non-neutralizing monoclonal antibodies (mAbs), which currently are not included in flu vaccines, researchers led by scientists from the Icahn School of Medicine at Mount Sinai and from the University of Chicago probed the binding properties of 12 mAbs, 3 of which were non-neutralizing, that were isolated from four people immunized with live-attentuated H7N9 avian flu vaccine.
The 12 mAbs bound to diverse sites on the virus's hemagglutinin head and stalk, including epitopes (sites at which antibodies bind) outside the receptor-binding site and four previously unidentified sites. Competition assays on the non-neutralizing mAbs found that they bound to different sites than did the neutralizing antibodies and potentially offered protection against H7N9 by spurring phagocyte uptake of epitopes, the authors said.
When vaccinated mice were challenged with the H7N9 virus, all 12 antibodies protected against mortality, with the non-neutralizing mAbs leading to more pronounced weight loss and a slower lowering of viral titers compared with the neutralizing mAbs. The non-neutralizing mAbs offered immune protection only if they were also broadly cross-reactive to H7 and H3 subtypes, the authors said.
Consideration of the role of non-neutralizing mAbs in immune response may lead to vaccines that offer broader protection against seasonal and avian flu strains, along with assays that can detect a wider range of antibodies that contribute to vaccine effectiveness, the authors said.
Jun 8 Cell Host Microb study
[h=3]China's Jiangsu province notes 2 new cases of H5N9 avian flu[/h] Two apparently new human cases of H5N9 avian flu from May are included in an update from Jiangsu province's Health and Family Planning Commission (HFPC) posted today by FluTrackers, an infectious disease news message board.
Although no English-language information is yet available on specifics of the cases, they were added to the FluTrackers case list, which now numbers 793 cases since 2013.
Jiangsu is a coastal province north of Shanghai. The fourth wave of H5N9 in China began last fall and so far shows a slowed pace from past waves.
Jun 9 FluTrackers posting
FluTrackers H7N9 case list
In other avian flu news from China, more details of an H5N6 case reported May 31 were provided by the country's National HFPC to the World Health Organization (WHO) and posted yesterday on the WHO Web site. The case-patient is a 50-year-old man from Hunan province who became ill May 23 and went to his village clinic the next day. On May 28 he was transferred to a hospital in critical condition, where he presumably remains.
His close contacts have so far remained healthy, but the investigation is ongoing.
Jun 8 WHO statement
May 31 CIDRAP News item on the case
Flu Scan for Jun 09, 2016
H7N9 vaccine antibodies; Avian flu cases in China
Filed Under:
Avian Influenza (Bird Flu); Influenza Vaccines; H7N9 Avian Influenza [h=3]Study: Non-neutralizing antibodies may play a role in flu vaccine protection[/h] Non-neutralizing, cross-reactive antibodies may play a role in fostering protective immunity following H7N9 avian flu vaccination and are likely missed by traditional vaccine immunogenicity tests, according to a study yesterday in Cell Host & Microbe.
H7N9 vaccine development has been stymied by the vaccine's questionable ability to spur a potent immune response. To identify the protective potential of non-neutralizing monoclonal antibodies (mAbs), which currently are not included in flu vaccines, researchers led by scientists from the Icahn School of Medicine at Mount Sinai and from the University of Chicago probed the binding properties of 12 mAbs, 3 of which were non-neutralizing, that were isolated from four people immunized with live-attentuated H7N9 avian flu vaccine.
The 12 mAbs bound to diverse sites on the virus's hemagglutinin head and stalk, including epitopes (sites at which antibodies bind) outside the receptor-binding site and four previously unidentified sites. Competition assays on the non-neutralizing mAbs found that they bound to different sites than did the neutralizing antibodies and potentially offered protection against H7N9 by spurring phagocyte uptake of epitopes, the authors said.
When vaccinated mice were challenged with the H7N9 virus, all 12 antibodies protected against mortality, with the non-neutralizing mAbs leading to more pronounced weight loss and a slower lowering of viral titers compared with the neutralizing mAbs. The non-neutralizing mAbs offered immune protection only if they were also broadly cross-reactive to H7 and H3 subtypes, the authors said.
Consideration of the role of non-neutralizing mAbs in immune response may lead to vaccines that offer broader protection against seasonal and avian flu strains, along with assays that can detect a wider range of antibodies that contribute to vaccine effectiveness, the authors said.
Jun 8 Cell Host Microb study
[h=3]China's Jiangsu province notes 2 new cases of H5N9 avian flu[/h] Two apparently new human cases of H5N9 avian flu from May are included in an update from Jiangsu province's Health and Family Planning Commission (HFPC) posted today by FluTrackers, an infectious disease news message board.
Although no English-language information is yet available on specifics of the cases, they were added to the FluTrackers case list, which now numbers 793 cases since 2013.
Jiangsu is a coastal province north of Shanghai. The fourth wave of H5N9 in China began last fall and so far shows a slowed pace from past waves.
Jun 9 FluTrackers posting
FluTrackers H7N9 case list
In other avian flu news from China, more details of an H5N6 case reported May 31 were provided by the country's National HFPC to the World Health Organization (WHO) and posted yesterday on the WHO Web site. The case-patient is a 50-year-old man from Hunan province who became ill May 23 and went to his village clinic the next day. On May 28 he was transferred to a hospital in critical condition, where he presumably remains.
His close contacts have so far remained healthy, but the investigation is ongoing.
Jun 8 WHO statement
May 31 CIDRAP News item on the case