High-dose vaccine more likely to protect against lab-confirmed flu
The high-dose flu vaccine is 38% more effective in protecting elderly people against laboratory-confirmed influenza than the standard-dose vaccine, according to a study of Veterans Health Administration (VHA) senior patients published yesterday in the Journal of Infectious Diseases.
The study involved VHA patients 65 years of age or older during the 2015-16 influenza season. To conduct the study, 9,091 standard-dose and 24,682 high-dose recipients were matched using electronic medical records.
In addition to its 38% advantage against lab-confirmed flu, the high-dose vaccine was 25% more effective in preventing influenza- or pneumonia-associated hospitalization, 7% more effective against all-cause hospitalization, and 14% more effective against influenza- or pneumonia-associated outpatient visits.
Seniors are one of the most at-risk population for complications from seasonal flu infections, including hospitalization. The authors said their study adds to a growing body of literature that suggests the high-dose vaccine should be used in senior populations.
"In protecting senior VHA patients against influenza- or pneumonia-associated hospitalization, a high-dose influenza vaccine was more effective than standard-dose vaccine," the authors concluded.
Feb 14 J Infect Dis study
CDC says flu sickens up to 35 million people in a season
Centers for Disease Control and Prevention (CDC) experts analyzed data from six recent flu seasons and determined that the number of influenza-related illnesses during each season ranged from 9.2 million to 35.6 million, including 140,000 to 710,000 influenza-related hospitalizations. Their findings were published in Influenza and Other Respiratory Viruses.
The six seasons analyzed (2010-11 through 2015-16) followed the 2009 pandemic year, and to conduct the study researchers used information gathered from the Influenza Hospitalization Surveillance Network, among other databases.
People over the age of 65 represented the greatest number of flu hospitalizations, ranging from 87,000 to 523,000. Children ages 5 to 17 years were the least likely to be hospitalized for influenza. Seasons 2012-13 and 2014-15 had the most activity.
The authors also used vaccine effectiveness estimates for each season to estimate how many illnesses the vaccines prevented, which reached a peak in 2013-14, when an estimated 86,730 hospitalizations were averted. CDC data show vaccine effectiveness that year of about 51%.
The authors of the study said annual estimates of influenza burden of disease, including related hospitalizations, can help with public health decision making, vaccine production, and disease surveillance.
"Burden estimates are invaluable for estimating the economic and societal costs of influenza and making decisions about procurement of vaccines and influenza antivirals before the influenza season begins," the authors concluded.
Feb 14 Influenza Other Respir Viruses study
CDC 2013-14 flu data