How the Flu Vaccine Might Help You Beat COVID

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I’ve been a fan of vaccines for a long time. Like, easily since I was a toddler and, according to my mom, I insisted on staring with abject delight at the needle as it went into my arm, while asking the medical professionals questions about what was happening. 

Fast forward to my 20s, it makes sense that as anti-vaccine jackoffs like Jenny McCarthy started gaining popularity, I hit back by encouraging people to ignore them and get themselves and their kids healthy with safe and effective vaccines. I even organized vaccine clinics at conventions like DragonCon, where we vaccinated hundreds of people against pertussis, tetanus, diphtheria, and influenza.

So obviously, these days I’m living my best life. I’ve been vaccinated SO MANY TIMES in the past year! Johnson and Johnson viral vector COVID vaccine. Pfizer MRNA “booster” vaccine. And most recently, a flu shot! It’s great. Loving it.

Okay, I’m kind of kidding. Most (normal) people don’t love getting vaccinated, considering that it usually leaves you a bit under the weather afterward as your immune system gets to work on its new job, which is why I like to make each vaccination a fun combo of shots and (whiskey) shots. One for one. As a treat!

I’ve noticed a common theme amongst people who reject the COVID vaccine (and then often end up on ventilators or dying) is the idea that “I trust my immune system so I don’t need a vaccine.” Well, several new studies have come out recently that should put this into perspective. First up, in August some researchers published a paper looking at about 75,000 people across six different countries, all of whom tested positive for COVID-19. They found that the people who had had a flu shot in the past six months were way more likely to stay healthy. Again, that’s not a COVID vaccine — an influenza vaccine. The people who were not vaccinated against influenza were 58% more likely to go to the emergency room, 58% more likely to experience a stroke, and 20% more likely to end up in the intensive care unit.

Does this mean that the flu vaccine, which specifically targets the influenza virus and not SARS-CoV-2, somehow boosts immunity against COVID? Not necessarily! First of all, they did NOT find a link between flu vaccine and death from COVID. Second of all, this could just be a correlation, based on the idea that people who get flu vaccines are more likely to also take care of their health in other ways.

But! This isn’t the only study looking at the link between vaccines for other things and COVID. This paper cites an exploratory study published in Nature back in February that found that “polio, Haemophilus influenzae type-B (HIB), measles-mumps-rubella (MMR), Varicella, pneumococcal conjugate (PCV13), Geriatric Flu, and hepatitis A/hepatitis B (HepA–HepB) vaccines administered in the past 1, 2, and 5 years are associated with decreased SARS-CoV-2 infection rates, even after adjusting for geographic SARS-CoV-2 incidence and testing rates, demographics, comorbidities, and number of other vaccinations.”

But wait, there’s more!

A few weeks after the influenza vaccine study was published, pathologists found that “prior MMR or Tdap vaccination correlates with reduced COVID-19 severity.” And this wasn’t just a study looking at who has been vaccinated and who got bad COVID symptoms — I mean, they DID do that and they DID find that patients who previously had an MMR or Tdap vaccine enjoyed decreased severity of COVID-19 symptoms — but this paper goes a step further, in that they gathered blood samples from people who were COVID positive and looking at their T-cell responses in the lab.

As I described previously, vaccines work by priming your immune system in a few ways. They stimulate your B-cells to produce antibodies and your T-cells to attack infected cells. The antibodies hang around for awhile but eventually they fuck off if the threat is over. But your B-cells and T-cells tend to remember the instructions for responding to an infection, so even though the antibodies are gone, your body can still launch an adequate defense in the future.

Researchers at Brigham and Women’s Hospital were studying T-cell responses in the blood of COVID patients and people who were vaccinated against COVID, and as a control to compare it to, they used the blood of people vaccinated against MMR and TDaP. T-cells have antigen receptors — little nubbins that stick out and do the job of attacking a virus in a cell. The researchers noticed that the receptors in the COVID batch were identical to the receptors in the MMR and TDaP batch, meaning that maybe those receptors can attack all of these viruses.

And the cohort study bears it out — like those previous studies, the Brigham team found that previous vaccinations reduced the severity of COVID symptoms. “They found that patients who had previously been vaccinated for MMR had a 38 percent decrease in hospitalization and a 32 percent decrease in ICU admission/death. Similarly, patients previously vaccinated for Tdap had 23 percent and 20 percent decreased rates, respectively, of these outcomes.”

Our immune system truly is incredible, which brings me back to the idea that we should “trust” our immune system instead of getting vaccinated, as 58-year old lawyer and vlogger Leslie Lawrenson said right before he died of COVID-19.

Imagine your uncle has booked a week-long working tour on a small sailboat. “But Uncle Joe,” you say, “do you even know how to swim?”

“No,” he scoffs. “Not necessary!”

“But what if you fall in the water? Will you wear a life vest?”

“Of course not,” he says. “Most people who go sailing don’t fall in the water! Life vests are uncomfortable and don’t look good on the ‘gram.”

“Will you take a swim lesson at least, just in case?”

“Absolutely not,” he says. “I know a friend who took swimming lessons and the next day his body was tired and sore.”

“Well yes, that’s what happens when you build muscles!”

“I don’t need to build muscles. I trust my body!”

Spoiler alert, Uncle Joe is now dead at the bottom of the sea. Because we don’t just trust our bodies to do what we need them to do in times of trouble. If we want our muscles to be strong, we train them. If we want to get better at something, we practice. We don’t just go climb a mountain, or win a chess tournament, or sail around the world and expect our bodies and brains to do what we want with zero prep. 

And it’s the same for the immune system! I DO trust my immune system, which is why whenever I can I give it the necessary instructions and training to keep me safe. And just like doing pushups helps me be a better surfer, and doing yoga helps me be a better hiker, training my immune system with one vaccine might help me not just in that specific way but by improving my health overall.

So, consider this your reminder that it’s October, the perfect time to go get your flu shot, which is either free or like $20 depending on your insurance carrier and takes all of 30 seconds. Not only might you help save lives (considering that flu is a serious mortal threat to older and immunocompromised people every year) but you also might help yourself experience fewer days of torture if you end up catching COVID-19. Also, if it’s been ten years or more since you got your TDaP, it’s time to re-up that, too! That includes all of you we vaccinated at DragonCon, because that was 2010. Which was ten years ago. What even is time?

Rebecca Watson

Rebecca is a writer, speaker, YouTube personality, and unrepentant science nerd. In addition to founding and continuing to run Skepchick, she hosts Quiz-o-Tron, a monthly science-themed quiz show and podcast that pits comedians against nerds. There is an asteroid named in her honor. Twitter @rebeccawatson Mastodon Instagram @actuallyrebeccawatson TikTok @actuallyrebeccawatson YouTube @rebeccawatson BlueSky

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  1. There was also a big joint study, between scientists in Australia and Belgium iirc, to investigate the usefulness of the BCG vax to help prevent COVID. Announced with much fanfare in early 2020 but seems to have disappeared without a trace.

  2. Thanks for the TDaP reminder. I don’t recall when I last had that so it’s likely been more than 10 years.

  3. MMR. eh? I’ve never gotten MMR, because my doctors always felt it was unnecessary. I had measles when I was a baby (and almost died) and mumps and rubella when I was in 5th or 6th grade (before any of those vaccines were developed.) In the last month, I’ve had my flu shot, my first dose of Shingrix and my Pfizer booster. Only the Pfizer caused any side effects, sore and stiff biceps and feeling very crappy for about 12-14 hours starting about 24 hours after the shot. Took an Advil and went to bed, and when I woke up about 3 AM, I felt fine.

    On a scale of 1 to 10, the Pfizer shot was about 1.1, where 10 is dying and a severe case of COVID is about 8. So yeah, worth it.

    Maybe the dead antivaxer put dying at 2.2 and put any needle at 3? After all, we are all entitled to our own opinions (>>insert emoji for snark here.<<)

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