Lyme vaccine: a glimmer of hope?

When the neighborhood chit chat inevitably ends up talking ticks, Lyme, and pesticides – you know there’s a problem. A big problem. A 300,000 cases of Lyme a year kind of problem. Which may not seem like a lot, until you look at a map and realize most of these are here in the Northeast U.S. So, if we’re not talking about permethrin impregnated pants then we’re talking about who’s on doxy this week, and why, if our dogs are vaccinated – isn’t there a human vaccine?! (Which I touched upon here.) Even in my ecotoxicology class, Lyme disease has a way of making its way into our discussions.

Map of the United States showing reported cases of lyme disease.  The cases are concentrated in the north east quarter of the country

CDC map

Yesterday it was antibiotic resistance (we were talking about pharmaceuticals in sewage water and sludge). “When I was a kid,” one student said, “I had a lot of ear infections,” and, she continued, a lot of antibiotics. “That wouldn’t happen today.” Which is true, and for good reason, because many ear infections are caused by viruses that won’t respond to antibiotics. But here in tickville I imagine there is one antibiotic whose popularity is growing: doxycycline. Used to treat Lyme, plenty of my neighbors and my neighbor’s dogs (including our Ella – tested, retested, diagnosed and treated for a grand total of $180) are popping the doxy or similar drugs. And while I won’t get into the controversy about chronic Lyme and treatments, as I’ve become more aware of the impacts of antibiotics on our own microbiome and resistance, I’ve wondered too about the impact of doxy on one’s microbiome. And I’ve wondered when we might start hearing about resistant Lyme.

Fortunately a recent group of researchers who tried to push the bacterium to evolve under pressure from antibiotics in the lab– failed (although failure in the laboratory doesn’t always mean failure in Nature – just ask any grower who uses Roundup, the apparently “evolution-proof” herbicide). Still, so far so good. Except, evolved resistance isn’t the only way a bacterium can beat out our attempts to poison them into oblivion. In 2015 Kim Lewis and colleagues found that Lyme bacteria is particularly good at forming “persister cells.” That is they manage by essentially going dormant, sort of like rolling up like a pill-bug, until the coast is clear.  Then they once again go forth and multiply. While scientists and physicians debate the meaning of this (does this help explain how Lyme behaves in some patients,) the utter tenacity, the insidious nature of Lyme and its hosts and vectors (like the poppy-seed sized nymph that may find its way into a bodily crevice or hide along a hairline) and growing number of victims makes a vaccine seem like an increasingly brilliant solution.ixodes_scapularis_all

So where are those vaccines? With the 1990s vaccine long-gone thanks in part to anti-vaxxers; side effects (although based on just a bit of bacterium that could set off immunity – it could not itself cause Lyme; and the FDA eventually concluded that arthritis at least, was not associated with vaccination); and economics – times have changed. Now, diagnostic labs are testing upwards of 2.4 million blood samples a year (and finding infection in about 288,000 of them).

Now, there is a glimmer of hope. In the waning days of 2016 the FDA gave the go-ahead for a new Lyme vaccine. Let’s hope that this one makes it through the billion dollar venture of safety and efficacy testing. Then of course we’ll have to deal with those other-tick borne diseases. But for now I am cautiously optimistic that one day soon we can stop chit-chatting about Lyme!

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