Shiloh
Editor, Senior Moderator
Source: http://www.cidrap.umn.edu/news-perspective/2016/07/flu-scan-jul-05-2016
Flu Scan for Jul 05, 2016
Flu vaccine H3N2 protection; Winter temps and flu deaths
Filed Under:
Influenza Vaccines; Influenza, General
[h=3]Flu vaccine more effective than thought in mismatched year[/h] A new study in Clinical Infectious Diseases reports that the flu vaccine in 2014-15 was more effective than expected in hospitalized adults, including those 65 or older.
Influenza H3N2 strains were severe and circulated widely from November 2014 to March 2015, but they antigenically drifted from the viruses used in that year's flu vaccine. Previous studies showed that this led to less-than-optimal vaccine protection, especially in hospital settings. But researchers investigating patients at two hospitals in Michigan found that the vaccine was 43% effective against H3N2 in all adults, and 48% effective in those 65 or older.
Both numbers are higher than previous studies found for H3N2 protection that season.
Vaccine effectiveness was determined by contrasting the vaccination status of those who tested positive for H3N2 against those who tested negative for the virus. Of the 624 adults hospitalized for acute respiratory illness, 421 (68%) were vaccinated, and 98 patients (16%) tested positive for influenza A. Among 60 (61%) of influenza A virus samples, 53 (88%) had drifted to the 3C.2a genetic group.
"We can be encouraged by the current results which suggest that inactivated vaccines may perform better in preventing hospitalization than milder disease in a year with antigenic drift," the authors said.
Jul 1 Clin Infect Dis study
[h=3]Study: Warmer winters may curtail flu-related deaths[/h] Because of the association between cold winter temperatures and flu fatality rates in Europe, warmer winters might mean fewer influenza deaths, European researchers reported yesterday in Nature Climate Change.
The investigators analyzed daily regional mortality data from 1998 through 2005 for 16 European nations representing 405 million people. The countries used an identical method for collecting fatality data, which helped rule out confounding factors.
The team found a strong association in all countries but the United Kingdom, Netherlands, and Belgium between the year-to-year fluctuations in winter (December-to-March) mean temperatures and the number of flu deaths, with colder winters tied to higher fatality rates. For the 13 other countries, the correlation ranged from ?0.60 in Denmark to ?0.97 in Portugal, whereby ?1.0 would be a perfect correlation.
The authors write, "Despite the lack of a strong year-to-year association between winter mean values in some countries, it can be concluded that warmer winters will contribute to the decrease in winter mortality everywhere in Europe."
Jun 4 Nat Clim Chang study
Flu Scan for Jul 05, 2016
Flu vaccine H3N2 protection; Winter temps and flu deaths
Filed Under:
Influenza Vaccines; Influenza, General
[h=3]Flu vaccine more effective than thought in mismatched year[/h] A new study in Clinical Infectious Diseases reports that the flu vaccine in 2014-15 was more effective than expected in hospitalized adults, including those 65 or older.
Influenza H3N2 strains were severe and circulated widely from November 2014 to March 2015, but they antigenically drifted from the viruses used in that year's flu vaccine. Previous studies showed that this led to less-than-optimal vaccine protection, especially in hospital settings. But researchers investigating patients at two hospitals in Michigan found that the vaccine was 43% effective against H3N2 in all adults, and 48% effective in those 65 or older.
Both numbers are higher than previous studies found for H3N2 protection that season.
Vaccine effectiveness was determined by contrasting the vaccination status of those who tested positive for H3N2 against those who tested negative for the virus. Of the 624 adults hospitalized for acute respiratory illness, 421 (68%) were vaccinated, and 98 patients (16%) tested positive for influenza A. Among 60 (61%) of influenza A virus samples, 53 (88%) had drifted to the 3C.2a genetic group.
"We can be encouraged by the current results which suggest that inactivated vaccines may perform better in preventing hospitalization than milder disease in a year with antigenic drift," the authors said.
Jul 1 Clin Infect Dis study
[h=3]Study: Warmer winters may curtail flu-related deaths[/h] Because of the association between cold winter temperatures and flu fatality rates in Europe, warmer winters might mean fewer influenza deaths, European researchers reported yesterday in Nature Climate Change.
The investigators analyzed daily regional mortality data from 1998 through 2005 for 16 European nations representing 405 million people. The countries used an identical method for collecting fatality data, which helped rule out confounding factors.
The team found a strong association in all countries but the United Kingdom, Netherlands, and Belgium between the year-to-year fluctuations in winter (December-to-March) mean temperatures and the number of flu deaths, with colder winters tied to higher fatality rates. For the 13 other countries, the correlation ranged from ?0.60 in Denmark to ?0.97 in Portugal, whereby ?1.0 would be a perfect correlation.
The authors write, "Despite the lack of a strong year-to-year association between winter mean values in some countries, it can be concluded that warmer winters will contribute to the decrease in winter mortality everywhere in Europe."
Jun 4 Nat Clim Chang study