Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2013/10/flu-scan-oct-21-2013
Flu Scan for Oct 21, 2013
New approach for broad flu protection; Anaphylaxis after H1N1 vaccine
Filed Under:
Influenza Vaccines; Influenza, General; H1N1 2009 Pandemic Influenza
Study: Flu vaccine plus immune suppressor may offer broader protection
US researchers reported yesterday that giving mice a flu vaccine and simultaneously treating them with rapamycin, an immune-suppressing drug, caused them to generate antibodies that were protective against other flu strains, including H5N1 and H7N9.
The authors, from St. Jude Children's Research Center in Memphis and the Fred Hutchinson Cancer Center in Seattle, reported their findings in Nature Immunology.
The researchers infected groups of mice with an H3N2 flu strain by way of vaccination and treated them with rapamycin or a placebo for 28 days, starting the day before vaccination. When the mice were later exposed to an H5N1 virus, the rapamycin group had a much higher survival rate than the placebo group. In addition, rapamycin-treated mice had significantly higher survival when later exposed to H7N9 and H1N1 viruses, according to the report.
Further, when the team transferred serum from vaccinated to unvaccinated mice, the unvaccinated mice were also protected from later H5N1 infection, which indicated that protection came from antibodies rather than from other immune system components, according to a St. Jude press release.
Rapamycin inhibits the kinase mTOR, which is involved in cell survival and proliferation, according to the release. "Inhibiting mTOR disrupted generation of the antibodies that target specific regions of the HA [hemagglutinin] proteins that are unique to each flu strain," leading to a more diverse set of antibodies, it says.
Previous research has indicated that memory CD8+ and CD4+ T cells play a role in broadening the immune response against flu viruses, but the team found that CD8+ T cells were not required for enhanced protection in rapamycin-treated mice, the release states.
"The findings highlight a novel way to generate antibodies that recognize and target proteins shared by most influenza A strains rather than those unique to each strain," it says.
Oct 20 Nature Immunol study
Oct 20 St. Jude press release
Anaphylaxis elevated after H1N1 vaccination, Quebec study says
Anaphylaxis after receipt of the 2009 pandemic H1N1 (pH1N1) vaccine with the AS03 adjuvant was much more common in Quebec compared with seasonal trivalent influenza vaccine (TIV), according to a new study using active surveillance data published in Vaccine.
Data from passive surveillance has already identified 33 cases of anaphylaxis after receipt of adjuvanted pH1N1 vaccine in Quebec, a rate 20 times higher than for TIV without adjuvant in the previous 6 years in the province, the study authors say.
Using the Brighton collaboration case definition of anaphylaxis, the Quebec researchers identified 58 anaphylaxis cases via active surveillance, which represents an incidence of 13 cases per million doses administered, they wrote. TIV averages less than 1 case per million doses.
Oct 19 Vaccine abstract
Flu Scan for Oct 21, 2013
New approach for broad flu protection; Anaphylaxis after H1N1 vaccine
Filed Under:
Influenza Vaccines; Influenza, General; H1N1 2009 Pandemic Influenza
Study: Flu vaccine plus immune suppressor may offer broader protection
US researchers reported yesterday that giving mice a flu vaccine and simultaneously treating them with rapamycin, an immune-suppressing drug, caused them to generate antibodies that were protective against other flu strains, including H5N1 and H7N9.
The authors, from St. Jude Children's Research Center in Memphis and the Fred Hutchinson Cancer Center in Seattle, reported their findings in Nature Immunology.
The researchers infected groups of mice with an H3N2 flu strain by way of vaccination and treated them with rapamycin or a placebo for 28 days, starting the day before vaccination. When the mice were later exposed to an H5N1 virus, the rapamycin group had a much higher survival rate than the placebo group. In addition, rapamycin-treated mice had significantly higher survival when later exposed to H7N9 and H1N1 viruses, according to the report.
Further, when the team transferred serum from vaccinated to unvaccinated mice, the unvaccinated mice were also protected from later H5N1 infection, which indicated that protection came from antibodies rather than from other immune system components, according to a St. Jude press release.
Rapamycin inhibits the kinase mTOR, which is involved in cell survival and proliferation, according to the release. "Inhibiting mTOR disrupted generation of the antibodies that target specific regions of the HA [hemagglutinin] proteins that are unique to each flu strain," leading to a more diverse set of antibodies, it says.
Previous research has indicated that memory CD8+ and CD4+ T cells play a role in broadening the immune response against flu viruses, but the team found that CD8+ T cells were not required for enhanced protection in rapamycin-treated mice, the release states.
"The findings highlight a novel way to generate antibodies that recognize and target proteins shared by most influenza A strains rather than those unique to each strain," it says.
Oct 20 Nature Immunol study
Oct 20 St. Jude press release
Anaphylaxis elevated after H1N1 vaccination, Quebec study says
Anaphylaxis after receipt of the 2009 pandemic H1N1 (pH1N1) vaccine with the AS03 adjuvant was much more common in Quebec compared with seasonal trivalent influenza vaccine (TIV), according to a new study using active surveillance data published in Vaccine.
Data from passive surveillance has already identified 33 cases of anaphylaxis after receipt of adjuvanted pH1N1 vaccine in Quebec, a rate 20 times higher than for TIV without adjuvant in the previous 6 years in the province, the study authors say.
Using the Brighton collaboration case definition of anaphylaxis, the Quebec researchers identified 58 anaphylaxis cases via active surveillance, which represents an incidence of 13 cases per million doses administered, they wrote. TIV averages less than 1 case per million doses.
Oct 19 Vaccine abstract