Ticks are one of humanity’s most dastardly adversaries: tiny, at times nigh-invisible arthropods that burrow into your skin, leech your blood, and sometimes transfer debilitating disease before they vanish, without you ever knowing they were there. It can be only months or weeks later, when Lyme disease’s harrowing symptoms begin to take hold, that you realize the stealth attack even occurred.
These days, it seems like there are more reasons than ever to fear ticks. Their range is spreading into cities and entirely new geographic regions in the US. Their arsenal extends beyond Lyme disease: alpha-gal syndrome, a condition caused by tick bites that creates alarming allergies to meat, has become a serious concern for public health authorities this year.
Nearly half a million people are estimated to contract Lyme disease annually — and those numbers will continue growing. This year’s tick season is off to an especially rough start: Tick bites have been sending the residents of the Northeast to the emergency room at a higher rate than they have in almost a decade. The CDC reported an unusually high number of tick-bite ER visits in late April in almost all regions of the US, and they continued to rise through May and into June.
Ticks are, of course, not a new adversary. They have been around much longer than humans. “Ticks bit dinosaurs,” Rick Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies who studies tick-borne diseases, told me.
They have, unfortunately, been evolutionarily optimized to transmit diseases: they attach themselves to a host for days at a time, emit analgesics that mean bites might not be felt, deploy anti-inflammatories and antihistamines to escape detection, and secrete proteins that prevent the bacteria that they transfer into a host from being detected by the host’s immune system, allowing an infection to fester for a while before there is an immune response. They are also surprisingly hard to kill, capable of going into a state of suspended animation that allows them to survive in, for example, extremely cold conditions.
Something has changed recently, however. “The ticks are on the move. They are spreading,” Ostfeld said. “They're entering more populous areas outside the regions where they were just 10 or 20 years ago, 30 years ago.”
Both the black-legged ticks (which primarily transmit Lyme disease) and lone star ticks (which are responsible for alpha-gal) are heading northward. But scientists only partially understand why. Climate change is clearly a factor: As northern climes warm, the ticks are moving in. But they are also heading south — to the Carolinas and Virginia for example — to areas where it was already warm enough for them to thrive. Researchers aren't totally sure why: This could be the result of the deer population expanding or more land development in forested areas, leading to more encounters between ticks and humans.
The bottom line is that people who’ve never had to worry about ticks before now have to. But there’s good news. This is a fight we can still win — and everyone, from the scientists in the lab to those of us who live in ever-expanding tick country, all have a part to play.
What scientists are cooking up to win the battle against ticks
Scientists are making real progress in developing powerful new vaccines that could prevent tick-borne diseases in the first place, as well as more effective treatments for the people who do contract an infection.
In March, Pfizer reported the results of its Phase 3 clinical trials for a Lyme disease vaccine. It had a more than 70 percent success rate in reducing the likelihood of developing the disease, both one day after the final dose was administered and a month later. The company planned to submit the data to the federal government for approval, and the experts I spoke to said the shot would be a powerful new tool, especially for the communities where Lyme disease is endemic.
“I think that it should be part of our armament, that it will work for some communities, some areas, some populations,” Ostfeld said.
Other candidates for preventing Lyme disease are also in development: The University of Massachusetts Medical School's MassBiologics has developed a monoclonal antibody cocktail that could be given to somebody before they are exposed to potentially prevent the disease’s development. That treatment is set to enter clinical trials soon. And for alpha-gal syndrome, researchers are also probing whether existing anti-allergy drugs might be able to stave off its symptoms.
Over the long term, scientists aspire to create a universal anti-tick vaccine that targets the proteins in tick saliva and stops the transmission of any pathogens. The science is hard to crack, given the complexity of tick saliva, but it would represent a genuine breakthrough that could alter our relationship to these creepy-crawlies forever.
“If you want to develop an anti-tick vaccine, that's the ultimate goal. That's [stopping] any tick biting you from transmitting anything,” Maria Diuk-Wasser, professor of ecology, evolution, and environmental biology at Columbia University, who studies the ecological and environmental drivers of tick-borne diseases, told me. “The ticks have a very complex saliva, and it's very difficult to develop that. But I think that’s the ultimate solution.”
New antibody treatments that could treat Lyme disease are also being studied, combining existing drugs to try to find a more potent therapeutic. Scientists are also working to improve our tests for Lyme disease; blood-based tests can be inaccurate, but antigen-based tests that test for proteins — similar to the rapid Covid-19 tests — could allow us to identify Lyme cases sooner and get people antibiotics that prevent the disease’s development. Diagnosis for alpha-gal also continues to improve: Dr. Scott Commins, an allergist at the University of North Carolina at Chapel Hill who has studied the syndrome for years, told me that a decade ago, it could be as long as seven years before somebody was properly diagnosed; today, the timeline is more like 18 months.
So the future looks brighter — so long as politics don’t get in the way. Ostfeld was optimistic about the prospects for the new Lyme disease vaccine. His only concern was that the current federal health department has been so anti-vaccine.
“I'm concerned that we have a HHS infrastructure that basically fosters conspiracy theories about vaccines and that the willingness of the public to consider vaccines is crumbling, with huge negative health consequences for Americans,” he said. “So I'm worried that even with vaccines that are shown to be safe and effective, that we may not adopt them because of politicians that are undermining public confidence.”
Likewise, further cuts to federal science funding could slow down progress just as researchers seem to be turning the tide against the ticks.
“There's not a lot of funding for doing basic tick biology. There really isn't at the federal level,” Ostfeld said. “And now we're at risk of curtailing that even further because of the recent attempts to destroy American science by choking it off or having politicians decide what science should be done rather than scientists.”
What you can do to protect yourself from ticks
As we wait for those interventions to actually arrive at scale and as more people are being exposed every year to the risks from ticks, better precautions could still allow us to stop infections from ticks the old-fashioned way.
Here are some quick tips on how to manage the risk of tick bites as the weather warms and many of us start spending more time outdoors:
- Know the tick activity in your local area: Local and state health departments often publish warnings or general guidance.
- If you are camping or hiking or otherwise spending a lot of time outdoors, use an EPA-approved insect repellent.
- Avoid high grass and piles of leaves as much as possible.
- Check your clothes, body, and gear for ticks after you come inside.
- Examine your pets closely, checking in nooks and crannies — even between their toes — when they come in.
- Familiarize yourself with how to remove a tick and consider keeping a pair of tweezers or a tick removal device on you when you’re spending time outside.
You could also pre-treat your clothes with permethrin products, which can disable or kill ticks on contact, Diuk-Wasser said. “It's a really useful product that almost nobody knows that we can use.”
And you should remember that the ticks that you are looking for change over the course of the year. In spring, it’s the full-bodied adults that you probably imagine when you think of a tick. But as we move into the summer, you should be on the lookout for nymphs, which are much smaller and harder to spot.
“Now the nymphs are out, which are the ones that are so tiny most people miss. That creates a lot of misinformation — maybe you're like, ‘Oh, I don't find them. There's not as much of it,’” said Diuk-Wasser. “But really, June is the month where most people get Lyme disease.”
Her team has actually created a free phone app, The Tick App, which people can use to take a picture of a tick and send it in for identification. That lets someone know if they may need to get tested for something like Lyme disease.
And, as always, be your own advocate. If you see Lyme disease’s telltale bullseye rash or have an unusual reaction after eating meat, talk to a doctor as soon as possible. Commins said that in some parts of the country — like Long Island, where alpha-gal is already common — doctors and nurses are practiced at testing for alpha-gal. But in other parts where the syndrome is new, like the South, it might take multiple trips to the emergency room before they think to check for it. So if you are experiencing a new allergic reaction and have any reason to think you may have been bitten by a tick recently, you can ask for an alpha-gal test, he said.
With a few simple precautions, you can do a lot to mitigate the risks from ticks, despite their penchant for sneak attacks. And it’s never too late to start: Commins told me that preliminary evidence suggests that alpha-gal syndrome is not permanent. If a person can avoid further tick bites, the allergy should also dissipate over time.
“Any amount of tick prevention that you do is not wasted time,” Commins said. “The five minutes you spend spraying and taping…is really time well spent.”
And if vaccine and treatment development continues to progress, we may someday be able to defeat the ticks and the frightening pathogens they carry for good.
