We've totally crushed the flu virus this year

 As awful as the Covid-19 pandemic is, it’s given us at least one benefit: we’ve utterly crushed the flu virus.

That’s right–the flu has almost completely disappeared this year. A combination of social distancing, closed schools and businesses, dramatically reduced travel, and high flu vaccination rates has achieved something that most flu experts never thought possible.

Flu levels are so low, in fact, that one has to wonder if the flu will even come back next year. The levels now are far lower than we’ve ever seen in modern history. Let’s take a look at the numbers:

nfluenza cases reported to the CDC by US public health laboratories, 2020-2021 season. Data from the CDC, graph created by the author.

As you can see here, the very worst week had just 24 confirmed cases in the entire U.S. That is truly astonishing. And in 2021 so far, we’ve had 5 or fewer cases in the entire country each week. Basically, the flu is gone. To see how dramatic this is, let’s look at data from last year (the winter of 2019-2020), which was a typical flu season:

Influenza cases reported to the CDC by US public health laboratories, 2019-2020, season. Data from the CDC, graph created by the author.

As you can see above, the U.S. had about 3,000 cases per week in January and February of 2020, with a peak at nearly 4,000 cases.

The rate of influenza this year is over 100 times lower than it’s ever been. Why did this happen? It’s obvious: all of the precautions we’re taking to reduce the spread of Covid-19 have worked wonders to prevent the flu as well. In fact, they’ve worked far better for influenza than for the Covid-19 virus.

No one knows what the flu season will look like next year, but for now, at least we’ve won a clear victory against the influenza virus. That’s a bit of good news.

The flu vaccine is working well this year. It's not too late to get it.

Current flu trends for 2018-19. Brown shows H1N1 strains,
red shows H3N2, and yellow indicates the strain was not
genotyped.

The flu is widespread and increasing right now, according to the CDC.  At least 42 states were reporting high levels of flu activity as of the end of December 2018, and the rates are still climbing. In other words, we're in the midst of flu season.

Other than that, though, the news is relatively good. Here's why.

First, the dominant strain of flu this year is H1N1, which is the "swine flu" that first appeared as a pandemic in 2009. But pandemics don't have to come with high mortality rates, and as it turned out–luckily for humankind–the 2009 flu was milder than the previous dominant strain, H3N2, which first appeared way back in 1968.

This season, nearly 90% of the flu cases tested by the CDC are turning out to be H1N1, the milder variety. Although 10% of people are still getting the much-nastier H3N2 flu, it's good news compared to last year, when H3N2 dominated.

Back to the bad news (although this is old news): the 2009 swine flu (H1N1) didn't completely displace the older flu strain. Instead, we now have both types of influenza circulating, along with two strains of the even milder influenza B virus. Since 2009, the flu vaccine has to combat all 4 of these flu viruses, which is why you might see the term "quadrivalent" associated with the vaccine. That just means it targets all 4 different strains.

Back to the good news again: the vaccine this year contains just the right strains! This doesn't always happen; actually it happens much less frequently than anyone would like. But now that the flu season is under way, the CDC can test the circulating flu viruses and compare them to the strains that are targeted by this year's vaccine. This year, both the H1N1 and the H3N2 viruses match the vaccine strains really well, which means that if you got the shot, you are likely to be very well protected.

(Keep in mind that even in a good year, the vaccine isn't 100% effective, and you can still get the flu. But you are much less likely to get it than anyone who is unvaccinated.)

While I've got your attention, let me answer one of the top 10 health questions of the year: "how long is the flu contagious?" According to the CDC,

• the flu is most contagious in the first 3-4 days after becoming sick.

It continues to be contagious for up to a week, so if you have the flu, stay home! And make sure those around you avoid physical contact, as much as possible, and wash their hands frequently.

And while I'm at it, let's debunk a common myth:

• No, you can't get the flu from the vaccine.

So if you've put off getting the flu vaccine, it's not too late! The season is in full swing, but if you get the vaccine today, you'll likely have excellent protection for the rest of the season. Go get it.

How to treat the flu: a shopping guide

Flu season is upon us, and your local pharmacy may feature special displays with products claiming to cure or treat the flu (which is caused by the influenza virus). The array of products, and the claims featured on their packaging, can be bewildering. Which of them should you buy? Here is a quick guide. (Spoiler: if you want to know what really works, skip to the end.)

This photo from a local RiteAid shows their display of "alternative" treatments. Let's consider a few of them.

Alternative pills that claim to treat the flu. 

1. Across the top we have vitamin C drops, helpfully labelled "Defense" in large letters. You might think these would defend you against the flu virus, but you'd be wrong. Vitamin C has no effect whatsoever on the flu, and it doesn't prevent colds either. People have been taking it for decades, but popularity is no substitute for evidence.

2. The shelves include 11 different formulations of Airborne, with the phrase "helps support your immune system" prominently displayed. Does this product help your immune system fight off the flu? Not even a tiny bit. Airborne is nothing more than an overpriced vitamin supplement (including vitamin C), and it's on the shelf because of clever and misleading marketing. Back in 2008, Airborne settled a $23.3 million lawsuit over false advertising, which was filed because they called their product a "miracle cold buster." After the lawsuit, they simply re-labeled it as an "immune booster," which is vague enough that they've been getting away with this claim ever since. Save your money.
3. Several of the products here, notably Zicam, are basically sugar pills supplemented with zinc. Some time ago, there was preliminary evidence that zinc might reduce the duration of a cold, but there was never any evidence that it could work for the flu. (Aside: colds are caused by completely different viruses.) Once scientists looked at it a little harder, they discovered that zinc doesn't work for colds either, as I explained in a 2012 column. Zicam is marketed as homeopathic, a clever ploy that allows it to escape government regulation. Their marketing constantly dances around what is permitted, usually by claiming it provides "immune support." Sound familiar?

Very expensive sugar pills.

4. On the bottom shelf you might notice Oscillococcinum, a homeopathic remedy that is just a sugar pill. Oscillo's claims to treat anything are almost laughably ridiculous: its "active" ingredient is supposed to be an extract from the heart and liver of a duck, which is then diluted until even that ingredient is no longer present.  As you can see in the close-up picture here, it's not cheap: $31 for 30 pills.
The box also claims that it "reduces duration and severity of flu symptoms," a completely false claim. The FDA has issued warning letters about this before, pointing out that "These products have not been approved or otherwise authorized by FDA for use in the diagnosis, mitigation, prevention, treatment (including treatment of symptoms), or cure of the H1N1 Flu Virus." Apparently the manufacturers of Oscillo (and the numerous places that sell it) are just ignoring the FDA.

These are just the "alternative" treatments. Most pharmacies have an even larger selection of flu treatments with real medicine in them. Here's a photo from the same RiteAid, right next to the alt-med selections.  

Medicines that try to treat the flu.

The selection here includes pills and liquids in many shapes and sizes, and all of them have active ingredients that do indeed have some effects. But they don't actually treat the flu itself: instead, they treat some of the symptoms, such as pain and congestion. None of them work very well, although those that contain ibuprofen or acetaminophen do help reduce pain.

So what does work? The latest medical science offers only two options:
1. Vaccination. Get your flu shot! The flu vaccine isn't perfect, and it varies in efficacy from year to year, but it usually provides some protection. In the best years it can reduce your chance of getting the flu by 75% or more. It's far better to avoid getting the flu in the first place.

2. Oseltamavir (Tamiflu), available only by prescription, is the only anti-viral medication that has been shown to have some effectiveness against the flu. It's not great, but it can reduce the severity of symptoms and maybe shorten the duration of the illness by about 1 day. You have to see a doctor to get it, which means taking your (sick) child or self to a doctor's office and exposing other people to the flu. 

The bottom line: none of the treatments that you can buy without a prescription will cure the flu. The "alternative" treatments are completely useless, and the real medicines might help a little bit with symptom control. 

Your best choice, by far, is the flu vaccine. Unfortunately, the internet is filled with misinformation such as claims that the vaccine doesn't work, or that it can give you the flu, or (worst of all) the utterly discredited notion that preservatives in the vaccine cause autism. Some of the anti-vaccine nonsense has even been promoted by presidential candidates, namely Donald Trump, Ben Carson, and Jill Stein. By spreading these false stories, Trump and Stein are doing real harm to the public health.

Flu advice from a future doctor.

Finally, I want to give props to RiteAid for trying to get people vaccinated. In front of the same store at which I took these pictures were two large signs saying "Get your flu shot today." Inside the store, they had a special table with science-based information about the flu vaccine, which featured artwork from local children (one of them shown here) encouraging other kids to get vaccinated. Well done.

Scientists are creating a dangerous flu strain, just to prove they can

In an outrageous display of chutzpah, a group of flu researchers led by Ron Fouchier of Erasmus Medical Center in the Netherlands announced today, in a letter to the journal Nature, that they were planning to engineer the new H7N9 avian flu strain to give it new, possibly much more deadly capabilities.  Fouchier is the same scientist who, two years ago, adapted the highly pathogenic H5N1 flu strain so that it could be passed from human to human, which it cannot do in its natural form.  The resulting outcry delayed publication of his paper, but it eventually did appear.

Now they want to do the same thing, and much more, with the new H7N9 influenza virus, which has killed 43 people in China to date, and which epidemiologists are tracking with great concern.

They should track Fouchier and his lab instead.

Wait a second, protests Fouchier.  He promises that

"All experiments proposed by influenza investigators are subject to review by institutional biosafety committees. The committees include experts in the fields of infectious disease, immunology, biosafety, molecular biology and public health; also, members of the public represent views from outside the research community."

Sorry, but I'm not reassured.  Fouchier's group wants to do this research because it's all they know how to do - and, I suspect, because they enjoy the publicity.  Despite their claims that the research is vital to our understanding of the flu, none of their past work, including their work on H5N1, has changed our ability to respond to a pandemic.  As flu expert Michael Osterholm said in a report by the Associated Press:

"H5N1 surveillance is as haphazard today as it was two years ago. Should we do the work if it's not actually going to make a difference?"

Precisely.  Fouchier and his colleagues can't do surveillance, nor do they work on vaccine development.  They have laboratories where they can engineer the flu virus to make new strains, so that's what they want to do. Two years after their controversial H5N1 experiments, they haven't contributed to any improvement in our ability to control a pandemic, nor have they shown how to develop a better flu vaccine.  The benefits of creating a deadly new H7N9 virus are marginal, at best.

What about the risk? As reported in the Daily Mail, Fouchier and his colleague Yoshihiro Kawaoka themselves said

"H7N9's pandemic risk would rise 'exponentially' if it gained the ability to spread more easily among people."

Really?  And from this they conclude that it's a good idea to engineer a virus that can do exactly that - spread more easily among people? Are we supposed to take this risk because of some theoretical benefit from a vague "better understanding" of how mutations in the virus change its pathogenicity?

Although Fouchier is in Rotterdam, the NIH funds part of his work through the National Institute of Allergies and Infectious Diseases (NIAID).  Dr. Anthony Fauci, the head of NIAID, offered the reassurance that a special panel will review this H7N9 project, and

"If the risk is felt to be too high by this outside review, they will recommend it won't be done and we won't fund it."

Despite this additional oversight, I remain skeptical. These special panels tend to include other scientists who are very sympathetic with the work they're reviewing, as was demonstrated two years ago when the H5N1 work was published despite the grave concerns expressed by many outside the field.  I predict they will approve Fouchier and Kawaoka's experiments.

Here's a thought: put me on the panel: I've published multiple research papers on the influenza virus (including this paper in Nature and this paper on H5N1 avian flu), so I think it's fair to say I'm qualified.  But somehow I doubt they will do that.