Reports from Australia have caused mounting concern about flu season in the Northern Hemisphere, with record-high numbers of laboratory-confirmed flu notifications and outbreaks and higher-than-average numbers of hospitalizations and deaths
November 30th, 2017Chasing Seasonal Influenza — The Need for a Universal Influenza Vaccine
November 29, 2017
DOI: 10.1056/NEJMp1714916
“…..Seasonal influenza epidemics cause 3 million to 5 million severe cases and 300,000 to 500,000 deaths globally each year…… The United States alone sees 140,000 to 710,000 influenza-related hospitalizations and 12,000 to 56,000 deaths each year, with the highest burden of disease affecting the very young, the very old, and people with coexisting medical conditions….”
“…..Another factor that may alter the effectiveness of influenza vaccines is the substrate used to produce them. In the United States, most influenza-vaccine viruses are propagated in eggs, although a small proportion are produced either in cell culture or by expressing specific viral proteins using recombinant DNA technologies. During the egg-based production process, the vaccine virus acquires amino acid changes that facilitate replication in eggs, notably changes in the hemagglutinin (HA) protein that mediates receptor binding.3 Since the influenza HA is the primary target of neutralizing antibodies, small modifications in this protein can cause antigenic changes in the virus and decrease vaccine effectiveness. Egg adaptation has been postulated to contribute to low vaccine effectiveness, particularly with influenza A (H3N2) viruses; however, the true impact is largely unknown…….”
“….the CDC estimates that influenza vaccination averted 40,000 deaths in the United States between the 2005–2006 and 2013–2014 seasons….”