Welcome to another MedCram COVID-19 update.
Today we're gonna talk about vaccine efficacy.
I think that's an important topic, given the current situation at hand where we're talking
about vaccine efficacy and whether or not it's waning.
There's some data out of Israel that seems to indicate that this might be the case.
They've already approved booster shots in Israel for those over the age of 60.
And in this country, as you'll recall, a number of people were vaccinated over the age of
75 at the beginning of this year, in January and February, and it's been about 8 months
since that time.
So the question is, are we seeing a waning of vaccine efficacy in the United States?
To what degree is it going, and exactly how efficacious are the different vaccines that
are approved: the Pfizer-BioNTech, Moderna, and the Johnson & Johnson vaccine?
How efficacious are they against, specifically, the delta variant?
We've seen a lot of efficacy studies prior to delta, but the real question at this point,
since delta seems to be just about everywhere in the United States, is how effective is
it against delta?
So let's take a look at this study.
This was published in the CDC Morbidity and Mortality Weekly Report, and it's titled "Interim
Estimates of COVID-19 Vaccines Effectiveness Against COVID-19-Associated Emergency Department
or Urgent Care Clinic Encounters and Hospitalization Among Adults During SARS-CoV-2 B.1.617.2 (Delta)
Variant Predominance - Nine States, June-August 2021."
Now, again, no small study.
There was 32,000 medical encounters, 187 different hospitals, 221 different emergency rooms and
urgent cares, and this was done in a representative 9 states, Indiana, New York, California, Colorado,
Utah, Minnesota, Oregon, Wisconsin, and Washington.
It started in each areas when the delta variant was 50% or more in the cohorts that they tested
for.
And they looked at vaccine efficacy and used a model to adjust for age, geographic region,
calendar time, virus circulation, results within the surrounding counties, at the facility,
on the date of the event, and it was weighted for inverse propensity to be vaccinated or
unvaccinated.
And they're looking at vaccination status in the community, the number of people coming
into the hospital or urgent care or emergency room that are vaccinated, and then they're
actually testing for it.
And the way they define their cohorts, in terms of vaccinated or unvaccinated was: to
be vaccinated, you have to have had the Johnson & Johnson shot at least 14 days before the
medical encounter, or if it was the Moderna and Pfizer vaccine, the second shot had to
be at least 14 days before the encounter.
And that's for good reason.
It's because, that's when we start to see the highest levels of vaccination.
And that's not a change in the definition.
Of course, the unvaccinated were those that had no doses whatsoever.
If there were people in between that, let's say they had their second dose within the
14 days or if it was the Johnson and Johnson, a shot within 14 days, they were excluded
from the study, so we don't have that gray zone there of whether or not they were developing
immunity or not developing immunity, just taken out of the equation, so we can have
a clean study.
So let's take a look at this graphic.
And the first thing we're gonna look at here is COVID-19 hospitalizations.
And, again, what they're doing is they're looking at discharge summaries which are COVID-19-like,
in terms of their hospitalization.
So they came in with some respiratory issue, perhaps there was a pneumonia on the chest
x-ray, etc.
They broke it down into the unvaccinated as the reference, and the fully vaccinated as
the intervention group here.
And so you can see here that in the population, you'd imagine if there's a lot of people that
are vaccinated, that you're going to have fairly similar amounts, in terms of who's
coming in vaccinated versus unvaccinated.
And how are they coming in in terms of respiratory ailments?
And then they checked their SARS-CoV-2 and the percent based on what are in this row.
So, in other words, of the unvaccinated group that came in with COVID-related, or COVID-like,
illness, that they could look for, 1,316 of them, or 18.95%, were positive for SARS-CoV-2,
whereas in the fully vaccinated group, 235 or 3.1% tested positive for SARS-CoV-2.
And if you do the calculation, you'll see than in terms of preventing COVID-19 hospitalizations,
the vaccines as an all-group was about 86% effective at prevention.
That's a relatively high number compared to what we have been seeing outside of the United
States, and something that has stood up fairly well since the beginning of the year.
Now, if we look at emergency room and urgent care encounters, unvaccinated visits, 10,000
to the urgent care or the emergency room.
Full vaccinated, 7,000.
Now of these, how many had positive SARS-CoV-2 tests?
For the unvaccinated, 28.9% did.
For the vaccinated, only 7% did.
And again if we look at the efficacy in this, it was about at 82% efficacy rate, in terms
of prevention of these ED and urgent care visits.
Let's take a look at hospitalizations once again, but let's break it down.
And maybe get a little information as to why this is happening.
So if we look at the 18-74, basically, those less than 75.
So, here is <75 and here is >75 and we break it down that way.
Once again, we're gonna be looking at <75 unvaccinated, 5,700.
4,500 for the fully vaccinated.
1,252 for the unvaccinated and 3,125.
But if we look at the percent positive for SARS-COV-2 in the <75, 21% were positive for
SARS-CoV-2.
And 2.9% were positive under the age of 75 for SARS-CoV-2, giving an 89% efficacy rate.
That's the highest that we've seen so far in this cohort.
However, when we look at those that were older than 75, or equal to 75 years of age, now
notice here, this is a population that, generally speaking, is highly vaccinated, so we've had
very good success in vaccinating many of those people in nursing homes and over the age of
75 and have gotten lots of vaccinations, and you can see here that in terms of people coming
in and being hospitalized with a COVID-19-like illness, so in other words, pneumonia, things
that can still happen even though you might not be getting COVID, you can see that there
was a lot of admissions here in the fully vaccinated group.
But when you actually tested them for SARS-CoV-2, what you start to see is that even though
they're fairly similar, in terms of this -- so you might see this in some cases and it was
mentioned even in Israel, where they'll look in the intensive care unit and say there's
equal number of who are vaccinated and unvaccinated, but if you look at the number of people that
have actually been admitted to the hospital for similar illnesses that you would expect
to see and because there's more people that are vaccinated in this population, expect
to see more of those people, you'll see that there's still a difference between this.
So 10.5% of the people admitted for COVID-like illness was positive for SARS-CoV-2 and therefore
positive for SARS-CoV-2 COVID-19, whereas only 3.2% in the vaccinated group was.
Again, giving us an efficacy rate of 76%, albeit lower than the 89%, but still in a
reasonable area where we would say this would have met the criteria for emergency-use authorization,
even today with the delta variant.
And, again, this is 7-8 months out now at this point.
Most of these people who are age 75 have received their vaccine about 8 months ago, and even
despite the fact that they're over the age of 75 that it's been 7 or 8 months since they
received the vaccine and they're going up against the delta variant, we're still seeing
an efficacy of 76% at preventing the worst outcome for COVID-19, which is hospitalization.
But now this is where it gets interesting.
Because now, we're going to actually break it down, and we're going to, first of all,
look at the emergency room and urgent care encounters.
And we're going to break it down into the Pfizer, the Moderna, and the Johnson & Johnson
or, in this case, the Janssen as its known as, which is the one-shot.
Now, in all these cases, the unvaccinated control group is going to be the same in all
of those categories, because we're going up against the same, in terms of that.
And the number of people that have been testing positive for SARS-CoV-2.
And if we look at the Pfizer-BioNTech efficacy for prevention of an emergency room urgent
care visit, we see it is at 77%.
The Moderna is at 92%.
And the Johnson & Johnson, or Janssen Pharmaceutical product, is at 65%.
And this is against delta variant.
So those are your statistics there, in terms of efficacy for the vaccines, in the delta
variant, the most recent evidence that we have at this time here in the United States.
We'll do the same thing now for hospitalization.
And that's, that's really the key here is preventing hospitalizations, especially when
we're talking about situations in some states of the union, where the hospital resources
have run out.
There's a current situation that's going on in Idaho, but it's not limited to Idaho.
There are other states that are getting to that point.
They're running out of intensive care beds.
And so it's important that we have a tool in our toolbox to prevent hospitalizations,
especially when this is going on.
Let's go over the Pfizer-BioNTech, Moderna, and Janssen vaccines.
And we see here that the Pfizer-BioNTech is 80% effective at preventing hospitalization,
and the Moderna is 95% effective at preventing hospitalization.
And the Johnson & Johnson is 60% effective at preventing hospitalization.
If you'd like to read the article yourself, we'll put the link in the description below.
We recently had a chance to team up with Dr. Rhonda Patrick of FoundMyFitness, where we
went over very important and popular questions about the vaccine and COVID-19.
So I encourage you to check that out.
Thanks for joining us.