Dogs can get a Lyme disease vaccine. Why can’t humans?

JUDY WOODRUFF: This is peak season in the United States for Lyme disease, as people spend more time outdoors and can be at risk for tick bites.

Each year, at least 30,000 cases are reported, and researchers believe those estimates are low. Given its debilitating effects on some people, and after years of research, it begs the question: Why is there still no vaccine people can get to prevent Lyme disease?

Miles O'Brien has been exploring that for his weekly reports on the Leading Edge of science and technology.

MILES O'BRIEN: It looks like a routine medical visit, but Dr. Linden Hu of Tufts University is prepping a patient for a procedure that would tick me off.

DR. HU LINDEN, Tufts University: So now we're going to just put the ticks in there. They move really fast, so you keep an eye, too.

MILES O'BRIEN: He is placing 28 larval ticks on a volunteer's arm, hoping they will help solve some of the mysteries of Lyme disease.

KYRAN ROMANOWSKI: I'm nervous. I'm not particularly thrilled having 30 ticks in my arm.

MILES O'BRIEN: Kyran Romanowski was diagnosed with Lyme disease in June of 2016. His symptoms, achy joints, fatigue and memory recall lapses, have persisted long after he stopped taking antibiotics.

KYRAN ROMANOWSKI: Why am I still having these symptoms when I had all these courses of treatment? You know, is the bacteria still in my body? I don't know.

MILES O'BRIEN: Neither do doctors. About 10 percent to 15 percent of people who get Lyme report stubborn symptoms for months, even years, even after antibiotic treatment. Is it lingering damage from Lyme? Are the body's natural defenses stuck in attack mode? Or is it something else?

DR. LINDEN HU: So, another possibility is that the bacteria persist, and they haven't been eradicated by the antibiotic treatment, and that the immune system may still be recognizing them and fighting them and causing symptoms of inflammation and infection.

MILES O'BRIEN: Could the Lyme disease bacteria, Borrelia burgdorferi, be cleverly hiding inside the human body? Doctors cannot detect the organisms using existing blood tests, but Dr. Hu hopes Borrelia and ticks are like magnet and steel.

DR. LINDEN HU: The bacteria are so well-adapted to their natural vector, the tick, that they're able to sense the tick, and the tick acts as a concentrating vessel to allow you to better sample what's in the host.

MILES O'BRIEN: After removing these ticks, Dr. Hu will grind them up and test them for the Lyme bacteria.

The ticks have been bred in the lab, under sterile conditions, so if Borrelia is there, it can only have come from the patient. Deploying ticks as bacteria detectors may seem far from a practical test, but it could give researchers some ideas on how to devise one.

Rheumatologist Allen Steere and his team at Massachusetts General Hospital are working on better tests and treatments as well. His lab is filled with more than 40 years of blood, cells and tissues samples from Lyme suffers.

In 1975, Steere was the investigator who first connected the dots between a cluster of children with symptoms of arthritis in Lyme, Connecticut, and what came to be known as Lyme disease.

DR. ALLEN STEERE, Massachusetts General Hospital: My career has largely been focused on the elucidation of Lyme disease in human patients, what it's like clinically, development of diagnostic test and treatment strategies with various courses antibiotic therapy, but then also prevention of the disease by vaccination.

MILES O'BRIEN: The Lyme disease vaccine which he helped develop is a sore subject. Sold under the brand name LYMErix by SmithKline Beecham, now GlaxoSmithKline, it was first prescribed in 1998.

It was 80 percent effective at stemming the disease. But hundreds of recipients claimed the vaccine made their Lyme symptoms worse. Federal investigators found no scientific proof the vaccine was the cause of their complaints, but anti-vaccine advocacy groups threatened class-action lawsuits, and sales plummeted.

In 2002, SmithKline took LYMErix off the market.

DR. ALLEN STEERE: And I think the time has come to reconsider the decision. Lyme disease is the only infection that I know of for which there is an effective vaccine, but it's not available to the public.

MILES O'BRIEN: Unless you happen to be a dog.

Giselle, the miniature dachshund, is getting her Lyme vaccine shot at the Angell Animal Medical Center run by the Massachusetts Society for the Prevention of Cruelty to Animals. Her owner is veterinarian Susan O'Bell.

SUSAN O'BELL, Massachusetts Society for the Prevention of Cruelty to Animals: I just feel very fortunate that there are several Lyme vaccine options for dogs, although I have to say, when I pull ticks off of my children, I wish that I had some easy options like vaccination or prevention, like I can give for my dogs, because it's an issue for people and their pets alike.

It sure seems like something we should be working on to prevent, one way or another.

MILES O'BRIEN: And, in fact, the French biotech firm Valneva is in the first phase of U.S. Food and Drug Administration testing on a new vaccine that is similar to LYMErix.

In the 15 years since the vaccine was pulled off the market, Lyme has exploded into an epidemic; 300,000 people get it every year.

Kyran Romanowski hopes his five-day stint of tick hosting will in some way help reduce that number.

DR. LINDEN HU: It looks like a couple ticks have been fed and they're still feeding.

KYRAN ROMANOWSKI: Some people are grossed out. Why would you do that? And I told someone, and they freaked out. You are going to put 30 ticks on you. Are you crazy?

MILES O'BRIEN: He may not be squeamish, but he was pretty happy when Dr. Hu took them off.

DR. LINDEN HU: Glad to see them go, Mr. Romanowski?

KYRAN ROMANOWSKI: I am ecstatic.

MILES O'BRIEN: Dr. Hu would share that emotion if his results would stop this raging, uncontrolled epidemic.

For the PBS NewsHour, I'm Miles O'Brien in Boston.

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