The CDC has reported higher rates of seasonal flu cases and hospitalizations nationwide since November.
It took a while, but North Texas has begun seeing an acceleration during the last few weeks.
Parkland Health’s chief medical officer Dr. Joseph Chang explained the delay to KERA’s Sam Baker.
We had an unusually long, warm summer, really all the way into the middle of December. And so people were still spending a lot of time outdoors. Now, as the weather has really started to get cold, people are coming back indoors.
And so, over the last three weeks, we've seen a pretty fast rise in flu cases overall and admissions here in the hospital. Just to give you an idea, three to five, let's just say four weeks ago, we had less than ten flu admissions at Parkland Hospital on any given day that week. And now we're up to 20 to 30.
This took a while for everything to just begin to hit, I guess.
Exactly. We're really not seeing any difference in rates of flu vaccination. Specifically, right now, we're sitting in the high 30s, so we're about 36, 37% of Dallas County vaccinated for the flu. And historically, again, that's almost exactly where we usually are.
We usually peak somewhere between 40% and 45% of the population of Dallas County vaccinated for flu. If we don't get to 70% or so of vaccination of a community, we don't get any significant herd immunity. And so, hovering at about 30% to 40%, you're not going to see any herd immunity from folks who have been vaccinated versus those who have not been vaccinated. So, you're kind of on your own in terms of vaccination.
What type of flu is showing up most in the cases that are coming in?
Flu A a little bit more than flu B. But from a practical standpoint, flu A and flu B tend to be the same virulence. Really, the largest variation in determination of how severe your flu is going to be, number one, your own health state, and whether you're immunocompromised or not. And of course, if you got vaccinated or not.
People who are on chemo, people on immunomodulators for some sort of autoimmune disease. And obviously people who have diabetes, hypertension, and those kind of things are all going to be at increased risk for hospitalization.
Now the flu shot that we have for this year - how effective is that?
It's been very good this year, Sam. From the best data we have, we are in the range of 80% or so effective this year for the forms of the flu vaccine that are out there. And so that's pretty good. So we encourage folks to take advantage of that and get your flu shot.
And how long does it take that flu shot to become effective?
It depends on your immune system. But for most people, and when I say most people, I'm talking about greater than 90% of people you will see, between seven and 14 days depending on your immune system. But on the outside number, it would be 14 days. So, we always tell folks that you are considered fully vaccinated 14 days after you've got your shot.
It does not mean the vaccine does not have some efficacy and effectiveness even after one week. The earlier you get it, the better, obviously. But it really takes about two weeks for your immune system to have ramped all of that up.
That said, though, apart from the flu shot, what steps should we be taking to avoid flu?
The best thing for you to do is avoid folks with any symptoms of an upper respiratory infection. People who are coughing, sneezing, have a fever. Certainly, it's best to avoid those individuals.
Also, remember a flu virus can live on surfaces. So, washing your hands frequently is just one of those things that we got to remember to do.
The other thing to remember, though, is the hand sanitizers. It's been shown that hand sanitizer is more effective at killing the flu virus than washing your hands. Those little personal-size hand sanitizers - carry those around with you and use those frequently as you touch surfaces and go through your day.
The other thing is that if you are sick, please avoid other people. In our community, only about 35% are vaccinated right now. That means two out of every three people are unvaccinated, so you could certainly spread whatever viruses you have to those people.
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