We’re about a month away from the first day of summer, and from tick season –– the peak months of activity for these tiny biters— is already here. Typically the season runs roughly April through September, but the season is getting broader as climate change makes winters more hospitable for tick survival.
Currently, the best option is prevention, through measures like keeping grass cut low, treating clothes with 0.5% perethrin, using EPA-registered insect repellants, and other methods.
There’s plenty of reason to be concerned. The Centers for Disease Control and Prevention’s emergency room data in its Tick Bite Data Tracker reports that tick-bite ER visits are higher throughout the United States (outside of the South Central states) than they’ve been since 2017. The worst numbers so far in 2026 are here in the Northeast region of the country.
But maybe there will be hope in years ahead? For Lyme Disease Awareness Month, the Drexel News Blog checked in with Garth D. Ehrlich, PhD, a professor of microbiology and immunology, and otolaryngology-head and neck surgery at Drexel University’s College of Medicine about his experience researching Lyme disease and his thoughts on the prospects of a new Lyme vaccine.
Please briefly talk about your experience when it comes to Lyme disease and other bacterial pathogens.
I have been studying chronic bacterial infections, which most Lyme cases are, for 35 years. I brought the biofilm paradigm into medicine in the mid 90’s as a means to explain bacterial persistence and chronicity in the face of both the host’s immune response and bacterial resistance to antibiotics. I then coupled the biofilm paradigm with the ‘distributed genome hypothesis (DGH)’ (which predicted the bacterial pan-genome) forming the rubric of Bacterial Plurality. The DGH states that different bacterial strains of the same species often infect patients polyclonally (more than one infection simultaneously) leading to chronic disease because horizontal gene transfer (essentially bacterial sex) among the multiple strains provides for the constant generation of new bacterial strains with novel combinations of disease-causing factors during infection such that the body’s immune system is constantly chasing a moving target.
We published a paper last year showing definitively that the genus Borrelia (which contains the Lyme disease bacterium) is actually two different genera – i.e. it needs to be split into two. My other work in Lyme disease has been developing DNA-based diagnostics that we have used to characterize the microbiomes of ticks (which transmit Lyme and associated chronic infectious diseases and to examine the brains of patients who have died with Lyme disease). We have also been developing a new class of antibiotics that targets biofilm bacteria.
Pfizer recently announced that it will seek regulatory approval for a Lyme disease vaccine candidate. Is it too soon to celebrate what may become a viable vaccine for people looking for protection against Lyme?
Yes, it is too soon to celebrate. The results do support cautious optimism – I would be extremely careful in providing this vaccine to patients already with Lyme disease as it could trigger a systemic inflammatory response as these patients often display heightened sensitivity to foreign proteins.
How does this vaccine operate once injected into the body and how many doses does Pfizer say are needed?
This vaccine is designed to prevent transmission of the Lyme disease agent from ticks to persons, i.e. once the tick bites the persons antibodies would enter the tick and bind and prevent the translocation of the bacteria. It would likely not provide protection if a tick had bitten someone else immediately prior to biting the vaccinee as the Lyme agent would have already mobilized. The requirement for four doses makes compliance difficult. Many persons would find having to get four doses of a vaccine onerous.
Please talk a bit about how dangerous Lyme can be and the importance of removing ticks as soon as possible to prevent transmission.
Lyme disease, once it becomes chronic, is a lifelong disease. Once it infects the central nervous system, the heart, and other deep tissues it is not currently possible to completely eradicate; thus, patients will need episodic therapy for life. The best treatment is prevention. Whenever someone has been outdoors, they should have a partner inspect them for ticks which should be removed immediately. If ticks are found, the person should start on prophylactic antibiotics.
If regulators approve, how soon could this vaccine be offered at pharmacies?
I think we are still several years away from a commercial rollout.
Reporters interested in talking with Ehrlich should contact Greg Richter, an assistant director of media relations, at 215-895-2614 or gdr33@drexel.edu.
