Ticks and Lyme Disease: Your Questions Answered


Lyme disease, a tick-borne ilness that can cause long-term problems in some who catch it, is a growing health threat. The number of cases reported to the U.S. Centers for Disease Control and Prevention in 2019 was up more than 50% from 2004, and a warming climate is expanding the areas and seasons in which ticks thrive. This year, weather conditions may result in a larger-than-average tick population and increased risk of exposure, yet no vaccine is available. Sam Fazeli, a Bloomberg Opinion contributor who covers the pharmaceutical industry for Bloomberg Intelligence, answers questions about the disease and when protection might arrive. The conversation has been edited and condensed.

What is Lyme disease and how do you get it?

Lyme disease is the most common tick-borne disease in the developed world and is caused by a bacterial family of many species called Borrelia burgdorferi sensu lato, with 10% to 20% of ticks infected. When an infected tick “bites” or attaches itself to an animal or human, the overall risk of transmitting the bacteria is 1% to 2%, though it increases depending on the length of time the tick remains attached. If transmission does happen, the risk of developing Lyme disease is thought to be about 5%. Along with the fact that ticks are most concentrated in the Northeastern U.S., this is why the incidence is not huge, with about 10 per 100,000 in the U.S. in 2019, according to the CDC. The rate in Europe varies based on climate and forestation levels, among other things, with France for example recording 76 cases per 100,000 in 2019. The disease itself has three stages. The first is a local skin reaction. The next two  - which can last from months to years --  can manifest as neurological symptoms, such as nerve pain, facial paralysis and brain inflammation and joint pain (often referred to as Lyme arthritis). About 90% of cases do not go beyond the first reaction. While a large majority of people make a full recovery with treatment, some end up with longer-term problems. In rare cases, the bacteria can enter the heart, which can be fatal.

How is Lyme disease currently treated?
Antibiotics. The key is to notice the tick or the “bull’s-eye” rash that is caused by the tick bite early (if one develops) and start treatment even if no symptoms have developed. This essentially works as a prophylactic therapy. Antibiotics are also used for the more serious stages. But the earlier they’re used, the better.

What are the long-term health consequences of untreated Lyme disease? Is it worse in certain types of people?
You don’t need to be untreated to get longer-term issues. If treatment is not initiated quickly, arthritis and neurological issues can become permanent. The heart impact can be deadly.

There was a Lyme vaccine on the market once -- Lymerix from SmithKlineBeecham (now known as GlaxoSmithKline). Why was it pulled from the market? It was shown to be effective against Lyme disease in clinical trials.

There was slow uptake, and for many of the same reasons we’re seeing now with   Covid-19 shots – vaccine hesitancy and disinformation. Some experts even referred to the vaccine as a “problem-solver for the rich.” People were worried about longer-term side effects or that they would need booster shots. Longer term follow-up of the clinical trial and those who were vaccinated with Lymerix never showed any issues. But the vaccine was withdrawn from the market in 2002 because of declining sales, given all the misinformation, and SmthKline’s settlement  of a class-action lawsuit over alleged side effects. (The drugmaker did not admit fault or compensate  anyone who had used the vaccine.) In the end, demonization of the pharma industry and anti-vaccination falsehoods essentially took away a perfectly good vaccine. It is amazing that the same playbook is being used against Covid-19 vaccines. Clearly we don’t learn from history.

There is a new vaccine in development, from Valneva SE and Pfizer Inc. Does it look promising? When might that be available?

Is a vaccine likely to do better commercially this time around? It's sort of a tricky market -- only useful in a limited region for a disease that doesn't spread person to person and has rare bad outcomes.

Yes, but let’s not forget,cases of tick bites will increase, driven by climate change. So the commercial opportunity will be bigger than before. A recent research paper looked at the impact of climate change on various tick species. The milder winters and wetter, warmer summers are likely to continue to provide increasingly large habitats for ticks for longer periods. But changes in human behavior are likely to be the biggest driver of increased cases of Lyme disease. The Covid-19 pandemic has raised interest in outdoor activities, and that will increase the risk of tick bites. Of course, not everyone needs a vaccine for Lyme disease, and it’s likely that it would be recommended for those with increased risk because of their occupation or time spent outdoors in tick-prone areas. So it’s unlikely to be a huge market.

Will it have to be expensive to succeed?  Can it avoid misinformation and side-effect concerns?

I don’t think it needs to be expensive. A $100 course used in a few million recipients across different geographies comes to a tidy sum, but I doubt it will be a blockbuster vaccine. As for the second question, it’s hard to know, but given that these issues have crept up with Covid-19 shots, it’s clear that combatting anti-vaccination sentiment needs to be a big long-term public health priority no matter what.

What about antibodies as treatments or a short-term vaccine?

There is an antibody in development by the nonprofit organization MassBiologics. It is intended to be used as a pre-exposure prophylaxis (PrEP) with the idea being that at-risk people get a dose of the antibody to provide them protection against the infection in case a tick bites them. It sounds great, especially if it’s priced affordably. But the antibody (2217LS) is only in a phase I human trial designed to look at safety only. The good thing is that this is a subcutaneous injection, meaning that it can be administered easily, which is not always the case with antibodies. If it works, it could be a great complement to vaccines.   

Should everyone just get an antibiotics prescription at the beginning of the season and take it if they pull a deer tick off themselves? Or take a course of antibiotics at the end of the season, no matter what?

No – this is a bad idea. Antibiotics should never be used like this because it may contribute to the development of bacterial resistance. But people should alert their doctor immediately if they discover a worrisome tick bite or suspect an infection. Taking a course at the end of the season is bad – it will lead to problematic overuse because there’s a low rate of infection in the first place and a lower rate of disease and severe disease.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Sam Fazeli is senior pharmaceuticals analyst for Bloomberg Intelligence and director of research for EMEA.

©2021 Bloomberg L.P.

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