The 2017-2018 influenza season has been one of the most severe in recent years in North America, causing a disease burden throughout the United States comparable to that of the 2009 influenza pandemic.
Influenza spread across the entire continental U.S., simultaneously affecting nearly every part of the country. As of early March, the number of U.S. pediatric deaths associated with the disease surpassed 100, and the cumulative hospitalization rate had reached its highest level since at least 2010.
This season was dominated by the elusive influenza A(H3N2) virus, which causes particularly severe illness and largely eluded this season’s vaccine. Looking back, Infectious Disease News compiled five stories that captured some of the major developments during this influenza season and the challenges that lie ahead.
‘Flu is everywhere’: CDC notes severe but not unprecedented activity
The rate of influenza-related hospitalizations in the United States nearly doubled in just 1 week as the country deals with a severe but not unprecedented influenza season that is being dominated by a strain associated with reduced vaccine effectiveness and serious illness, CDC officials said. Read more.
Early estimates show low flu vaccine effectiveness in US
Early estimates published by the CDC today show that the influenza vaccine has been only 36% effective overall in the United States this season, and only 25% effective against the predominant circulating strain. Read more.
CDC committee votes to recommend nasal spray flu vaccine again
The nasal spray influenza vaccine will be available to patients in the United States again.
In a 12-2 vote, the CDC’s Advisory Committee on Immunization Practices said that providers should be able to offer FluMist Quadrivalent (MedImmune) during the 2018-2019 influenza season, reversing its last two recommendations. Read more.
New US flu vaccine likely to include different H3N2 component
Next season’s influenza vaccine will likely include a different H3N2 component.
WHO recommended today that two components of the Northern Hemisphere’s influenza vaccine be changed for 2018-2019, including swapping out this season’s H3N2 component for one that has performed better against recent viruses. Read more.
Flu illness declines for third straight week; pediatric deaths top 100
A particularly severe influenza season in the United States continued to lose momentum entering March, with illnesses declining for a third straight week. But the rate of cumulative hospitalizations due to influenza reached the highest rate since at least 2010 and pediatric deaths attributed to influenza surpassed 100, according to CDC data. Read more.