How is the 2016-2017 flu season turning out to be? Were the world’s health professionals accurate in predicting the strains of flu viruses in the 2016-2017 influenza vaccine?
Is The 2016-2017 Flu Shot Working?
For the 2016-2017 influenza season, the world’s leading health practitioners predicted what strains of flu would be troublesome this year. The decision as to what the flu vaccine will contain is made during the spring and summer months. This gives vaccine makers enough time to hopefully produce enough flu vaccines for the people lined up to get them.
For the 2016-2017 influenza season, the flu shot protects against:
1. An Influenza A/California/7/2009 (H1N1)pdm09-like virus.
2. An Influenza A/Hong Kong/4801/2014 (H3N2)-like virus.
3. An Inluenza B/Brisbane/60/2008-like virus (B/Victoria lineage).
Most flu vaccines guard against three strains of influenza, however, some contain four strains. For the 2016-2017 flu vaccines that contain four strains of the flu they will also include:
An Influenza B/Phuket/3073/2013-like virus (B/Yamagata lineage).
The effectiveness of the flu vaccine varies widely from year to year. Based on past studies, the flu vaccine has been anywhere between 9%-60% effective on any given year.
So How Is This Year’s Flu Shot Working?
Well, we’re only midway through the flu season. So far the Center For Disease Control (CDC) hasn’t put out their mid-season report. In light of that, it’s looking like this year’s flu season is going to be somewhat of a success in terms of matching the flu shot against the dominant strains of flu.
The chart to the right highlights this year’s flu season so far. Typical for a flu season, the winter months spike in flu activity. As you can see, as of the last week of December, the United States just started to hit the peak of it’s flu season. There has been a drastic increase in flu cases. Personally speaking, in the emergency room that I work, there have been many confirmed flu cases over the last couple of weeks.
What Are The Dominant Strains Of Flu For 2016-2017?
- Influenza A have made up 93.1 of flu cases.
- A(H1N1)pmd09 has made up 2.6% of influenza A cases.
- H3N2 strain has made up 95.7% of cases contained in this year’s flu shot.
- Various: 1.7% flu cases not subtyped.
- Influenza B have made up 6.9% of flu cases.
- Yamataga lineage has made up 35.6%.
- Victoria lineaage has made up 35.2% (this was in the 2016-2017 flu shot).
- Various: 29.2% not subtyped.
So what’s the takeaway for the 2016-2017 flu shot?
It’s too early to tell. Most of the confirmed influenza cases have been the H3N2 influenza A subtype contained in the 2016-2017 flu virus. However, it’s too early to tell how effective the flu shot is going to turn out to be. There are a couple of bottom lines and questions to ask. Did the flu shot prevent the flu? The other bottom line is, did the flu shot work at keeping people out of the hospital? Unfortunately we won’t know more about that until long after this flu season is over and all the reporting is in.
N.a. “Influenza. Weekly U.S. Influenza Surveillance Report.” Centers For Disease Control and Prevention. 28 January 2017. Web. 9 February 2017.