Remember influenza?  As we all know, this is a long-familiar virus, has been infecting humanity for thousands of years.  For the last many decades, maybe centuries, it has had the peculiar property of showing up in one season only to vanish in another.  This is the now famous seasonal influenza virus epidemic.

Around here, the seasonal influenza virus epidemic shows up around mid-December and goes away in April.  In 2019, it showed up here in mid-December, and right on time, it is now disappearing from Ohio as we speak.  If you go to the CDC website on flu, scroll down to the red, yellow, green map of the US and you can run an animation showing the virus appear and clear this season, and prior ones if you are curious.

No one knows why this virus, the influenza virus appears every December and completely disappears every April, or how that is even possible, but it does.

And so we are glad to report one hazardous respiratory virus, the influenza virus, is leaving us along until December.

Influenza v. COVID-19 by chance of needing a hospital if infected

As judged by how many people ended up hospitalized because of this virus, it was on the high end of a regular flu season.  Overall, 0.067% of those infected with influenza this season required hospitalization.  That compares to the 20-30% rate the SARS-CoV-2 virus causes one to need a hospital.

Influenza v. COVID-19 by mortality rate, including in children

By mortality, it was a fairly typical year for seasonal flu, nowhere nearly as deadly or severe as the 2017-2018 season.

By CDC estimates, roughly 55 million Americans got infected with this season’s influenza virus, and through March, about 24-63,000 have died.

One number we follow closely every year is how many children die of influenza virus infection every season.

The range is 110-188, and so far this year 162 children have died from the influenza virus, making this year again typical in terms of danger of influenza to children, which is to say, thankfully, very little danger of actually dying from the influenza virus in childhood.

Compared to the COVID-19 illness, there are far more childhood deaths in America from influenza than COVID-19, 162 v no more than 3, so far.

But the US has seen as many as 55 million people infected with influenza compared to just over 100,000 COVID-19 cases, again so far.

How well did the 2019-2020 influenza vaccine, flu shot, perform?

It did very well.  In children younger than 18 years old vaccine efficacy was 55% which is a very protective level of efficacy.   https://www.aafp.org/news/health-of-the-public/20200226interimfluve.html

The flu shot continues to reduce the chance of dying or being hospitalized by this virus, and works better in children than adults.

Advanced Pediatrics is ending its influenza virus vaccination program for this season, and will start up for the new season this fall with Flu Fest 2020, dates to be announced this fall.

BOTTOM LINES

1. It may be hard to remember, but we just got through a massive viral epidemic that is not a coronavirus, but was the seasonal influenza epidemic.  As usual, it appeared in December and is wrapping up right now, in April.
2. This seasonal influenza epidemic was fairly typical except for the number of infections caused by influenza B rather than influenza A in children this winter.  But overall, numbers of hospitalizations for Americans of all ages was typical for seasonal flu epidemics, and the number of children in America dying from the influenza virus thankfully remained below 200 as it has every year we have measured.
3. With the rapid disappearance of influenza virus infection, Advanced Pediatrics is now ending provision of new influenza immunization doses until we prepare for the 2020-2021 seasonal influenza epidemic.  It will appear in mid-December and we will hold our FluFest 2020 in time to prevent severe infection from this virus this fall.

We are glad to see the seasonal influenza epidemic fading away, right on time, and now once again hope all remain safe and well as the far less predictable coronavirus continues to spread.

To your health,
Dr. Arthur Lavin