Hello and welcome to Medicine with Dr. Moran. I'm Dr. Keith Moran. This
video is an update comparing Influenza to Covid-19 with recent Covid-19 statistics.
Many of my viewers have vastly different questions about the two illnesses.
As we're now into the Influenza season people want to know how these two conditions are different
and how they're similar. I will contrast them and at the end of the video talk about the odds
of dying from each, or if you like the odds of surviving. First both diseases Influenza
and Covid-19 are caused by viruses. The influenza virus is an acute respiratory illness with cough,
fever, and muscle aches. There are actually two kinds of Influenza viruses
A and B. Influenza B tends to cause a milder illness than Influenza A. The symptoms of
Influenza are very similar to Covid-19. Influenza occurs in outbreaks and epidemics worldwide
mainly during the winter season in the northern hemisphere and during the summer months
influenza occurs down south in Australia and other countries in the southern hemisphere.
It's typically a self-limited infection which means it goes away on its own without any specific
therapy. Flu season can last up to five months but does occur every year, The flu vaccine typically
is administered starting in October. The vaccine for influenza was first given in the 1940's.
When this began people quickly realized that the Influenza virus would mutate
so the vaccinations that were initially made lost their effectiveness very quickly
thus every year a new vaccine is generated. It takes about six months to produce enough doses of
a vaccine so that the prediction of the strain for the following year often takes place in February.
Flu viruses can mutate quickly and thus by the time the vaccine is ready
for injection the virus that's circulating the population may have changed significantly thus
the effectiveness of the vaccine can vary. We saw a low of 10% efficacy in the 2004-2005 season to
as high as 60% efficacy in 2010 and 2011. The last season that statistics were available for us was
the 2018-2019 U.S. season. This demonstrated that 50% of people received vaccinations that year.
In this particular flu season. the vaccine prevented 4.4 million cases of Influenza
58,000 hospitalizations and 3,500 deaths. So even with a less than perfect vaccine
which this particular one had about a 29% efficacy there were still significant results.
Medical researchers have been working for a number of years to create a vaccine that
targets the stable portion of the Influenza virus. In other words the part that does not mutate.
There are several universal vaccines in clinical trials right now three of them in particular are
in phase three trials. We are likely on the cusp of a universal flu vaccine. Now typically 10% or
20% of the general population are affected during an Influenza season but rates can go up to 50%
in an Influenza pandemic. We do have antiviral medications to treat Influenza. It's important
to give medicine to high risk people such as the elderly and anybody that's hospitalized.
They must be promptly initiated within 48 hours of symptoms though to have good effect
and the reason for this is there's little benefit to give the medication beyond this time. It is
recommended for individuals who are severely ill such as those requiring hospitalization for lower
respiratory tract infection ie Pneumonia those are the ones we tend to target with this medication.
For last year's flu season the CDC estimates that the influenza in the USA affected between 39 and
56 million people with 18 to 26 million medical visits and somewhere between four hundred and
ten thousand and seven hundred and forty thousand hospitalizations now this led to 24,000 to 62,000
deaths from the flu this slide shows a direct comparison between the 1918 Influenza pandemic
on the left and Covid-19 on the right. I want to talk about case fatality rates for a minute.
Case fatality rates are defined as the percentage of people who die from the virus divided by
the total number of cases that were present for medical attention. In the 1918 Influenza pandemic
based on statistics that we have from that time the case fatality rate was 2% to 4%. Now of course
it's likely if this pandemic occurred now in 2020 the numbers would be much lower as we're much
better at treating Influenza complications such as secondary bacterial infections.
For Covid-19 on the right the case fatality rate is in the 2% to 3% percent range.
In fact if you take the current number of deaths divided by the total number of cases
the value is 2.0% in the U.S as of today November 28.
This number of course has been falling for some time due to a number of factors.
Next I want to talk about statistics for seasonal Influenza which occurs every winter on this slide.
For this we will look at the infection fatality rate because we have good data on this and the
infection fatality rate is a little bit different than the case fatality rate. This actually is the
number of people who died divided by the total number of infections so I'm talking about not
just the cases that come to medical attention but actually everybody who gets the virus and
obviously the infection fatality rate is going to be much lower than the case fatality rate.
Now the infection fatality rate is the number that people really want to know and what this
is is it's the likelihood of somebody dying if they actually acquire the virus and typically
for influenza it's reported on the order of 0.05 to 0.15 as you can see from this line on the left.
For example based on previous slide that I showed you from the CDC the IFR would be 0.06 to 0.11
based on 24,000 deaths per 39 million infections or 62,000 deaths out of 56 million infections
and those were the estimated numbers I gave you earlier in the talk here from the CDC.
The infection fatality rates for Covid-19 depend on your age group just like
seasonal Influenza. Overall the CDC's best estimate is that it is 0.2 to 0.4%.
Now I want to show the recent CDC reported numbers from September 2020
which I've reported on previously. These are on the right of the slide underneath the title
Covid-19 and are listed by age. Now if you're under 19 years of age the infection fatality
rate for Covid is three and one hundred thousand another way of saying this is that if you're under
19 your chance of dying if you get the virus is 3 in 1000,000. If you're in the twenty to forty
nine age group the odds of dying is 1 in 10,000 It becomes 1 in 500 if you're in your fifties
and about 1 in 100 in your sixties. These are average numbers to keep in mind. Now if you're
over 70 it's 5.4% so you can see the numbers are starting to go up with age. Now the CDC
did not give any specific data if you're over 80 but it's obviously much higher than 5.4%.
The corresponding age-related infection fatality rates for Influenza are listed on the left
on the slide again by age for comparison. If you look generally at these data for Covid-19
and compare them to Influenza the overall IFR for all age groups is about three to four times
greater than that of the Influenza virus if you look at the older population in particular.
Remember this is a virus ultimately that you do not want to catch and so
it's important that you take the appropriate precautions as I've been saying in my videos.
Now specifically when you look at age groups comparing these two viruses one can see that the
significant difference in the likelihood of death is predominantly in the over 70 year old range.
For Influenza if you're in your 70s the likelihood of death is on the order of 1%
and if you're above the age of 80 it's in the 2% to 4% range
and contrasting this to the CDC figures for Covid-19 if you're over 70 it's 5.4%.
It's important to note that comorbidities play a significant role in any illness
not just infectious illnesses. This is important both for Influenza as well as Covid-19.
I made a separate video on risk factors or Comorbidities as we call them in medicine
and how they play into the odds of dying from Covid-19.
Of all the deaths from Covid-19 only 2% to 4% actually occured in people with no comorbidities.
So if you do have comorbidities now is a good time to try to address them
as many of these are actually very modifiable. It's important to be healthy. Sadly many patients
health have gone downhill in this pandemic as a reflection of many factors. Notably a recent
study which I reported on in this video How to tell if you're Healthy shows that only 12%
of adult Americans are actually healthy. One of the most obvious comorbidities is Obesity.
This is an obvious comorbidity but actually it's estimated that 50% of normal body weight adults
are not healthy either. You should be aware that many comorbidities such as Diabetes,
High Blood Pressure, Obesity can be reversible. I encourage you to work with your health care
provider to address comorbidities if you have them. Even if you do not have comorbidities
the importance of a good diet, exercise, stress reduction, and sleep cannot be emphasized enough.
Supplements such as vitamin D plus or minus other vitamins and minerals if you're deficient such as
B12, Calcium, Magnesium, Zinc are important as well. I hope you enjoyed this update on
the odds of dying from Covid-19 as it compares to Influenza. Thanks for joining me today on
Medicine with Dr. Moran. I'm Dr. Keith Moran and as always get healthy and stay healthy.