Major New Lyme Vaccine Clinical Trial Coming To Nantucket

A major new Lyme vaccine clinical trial is coming to Nantucket this summer.

With Nantucket’s incidence rate of tick-borne diseases among the highest in the nation, the pharmaceutical giant Pfizer will look to test its new vaccine - now in the third and final phase of study - on the island’s vulnerable population.

Nantucket residents will soon have the opportunity to sign-up for the clinical trial later this summer, as Pfizer is contracting with Care Access, a decentralized research organization, to bring a mobile site vehicle to the island.

Care Access has partnered locally with Dr. Tim Lepore, the island’s leading expert on tick-borne diseases, as well as Briarpatch Pediatrics’ Dr. Leif Norenberg, to help roll out the clinical trial on Nantucket.

“I think it’s interesting and exciting for the island,” Dr. Lepore said. “I’m recommending it to my patients. I think it’s going to be significant.”

Pfizer and Care Access will begin officially enrolling participants in the trial over the summer, but will launch an education and recruitment campaign this month.

“The study we are bringing to Nantucket is a very large, phase 3 study looking to bring a true vaccine to this disease,” said Tyler E. Miller, MD, PhD, Care Access’ director of patient access. “Care Access is planning on opening a location on the island to enable people locally to easily participate if they would like to. We want to bring it to places where Lyme is endemic and bring it to people who are most affected and stand to benefit the most from a vaccine.”

The vaccine is a “traditional protein-based vaccine,” Dr. Miller said, and is not an mRNA vaccine. Dr. Lepore described it as similar to the LYMErix vaccine that was available in the late 1990s before it was pulled from the market over concerns regarding autoimmune reactions, despite evidence it was safe.

“LYMErix was very effective and we had good success with it here,” Lepore recalled. “It’s very similar to that vaccine. I was buying lots of LYMErix, in large amounts, and there was a real demand for it here. People were very upset (when it was pulled).”

Miller said that while they are indeed similar, there are key differences in the Pfizer vaccine under development to address the potential reactions observed with LYMErix.

"The protein used is slightly different and the vaccine components are different," Miller said. "For anyone who had a concern over that vaccine, I just want them to know this formulation is trying to address those concerns while still being effective."


Nantucket continues to have one of the highest incidence rates of tick-borne diseases in the country, with Lyme disease the No. 1 culprit. Since 2019, more than 500 cases of Lyme have been diagnosed on Nantucket, according to Nantucket Cottage Hospital’s infection prevention manager Elizabeth Harris.

And that number is strictly confirmed laboratory tests, so it doesn’t include cases in which clinicians diagnosed obvious incidences of Lyme disease (for example, when a patient’s bullseye rash is prominent) and prescribed antibiotics without laboratory confirmation. It also does not encompass patients who may have acquired Lyme disease while visiting Nantucket but were diagnosed elsewhere.

Nationally, the CDC estimates that Lyme disease affects more than 300,000 people annually.

Participants in the Pfizer trial would receive three doses: one shot during the summer; a second shot 50 to 70 days later, and a booster dose around April 2023. Half of the recipients would receive a placebo.

Overall, the study aims to have roughly 10,000 participants in multiple locations around the U.S. in the third phase of the trial, and a total of 18,000 globally.

In New England, the trial will include areas of Maine, where residents recently learned of the pending clinical trial.

Anyone between the ages of 5 and 85 will be eligible to participate, although there will be caps on the number of patients in different age groups. Individuals who have previously had Lyme disease will be able to participate in the trial, but those who have had the LYMErix vaccine, or a severe case of Lyme, will be prohibited. In addition, there will be a restriction on anyone who has had a tick bite within the previous four weeks.

Given Nantucket’s high incidence rate, that may preclude a large number of people, but Miller said the island community is still an ideal place to enroll participants in the trial.

“It’s the right population,” he said. “Nantucket has one of the highest risks in the country.”