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Home » Valneva-Pfizer Lyme disease vaccine — phase 3 trials to start soon

Valneva-Pfizer Lyme disease vaccine — phase 3 trials to start soon

There is a new vaccine that is under investigation that could help us stop Lyme disease, and it’s beginning phase 3 clinical trials soon. That means we could have this vaccine widely available in just a few years.

Of course, dogs have had access to a Lyme disease vaccine, but there has not been a vaccine available for humans for over 20 years. It’s not that dogs are more important than humans (though many of us might argue that point), it’s just that about 20 years the anti-vaxxers got the vaccine pulled from the market, one of their few “successes” in getting rid of useful vaccines.

But a small company, Valneva, is getting a safe and effective vaccine moving down the development pathway. Hopefully, we’ll have it in just a few more years.

Let’s take a look at this disease.

What is Lyme disease?

Lyme disease is an infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Of the three species, Borrelia burgdorferi is the main cause of Lyme disease in North America, whereas Borrelia afzelii and Borrelia garinii are more prevalent in Europe. The disease was named after the towns of Lyme and Old Lyme, Connecticut, where several cases were initially identified in 1975.

Borrelia is transmitted to humans when bitten by infected ticks which belong to a few species of the genus Ixodes, called “hard-bodied” ticks. Although deer ticks, Ixodes scapularis, Ixodes pacificus, or Ixodes ricinus, are commonly considered to be the vectors for Borrelia infection, some of the other species in the Ixodes genus can transmit the disease. Lyme disease is the most common tick-borne disease in the United States.

There are several initial symptoms of Lyme disease – fever, headache, fatigue, depression, and a circular skin rash called erythema migrans (EM). If the Borrelia infection is not treated quickly, further symptoms may appear that can involve the joints, heart, and central nervous system.

There is generally only one known treatment for a Borrelia infection – antibiotics, which may include doxycycline, amoxicillin, and cefuroxime. Generally, the symptoms of the infection resolve after antibiotic treatment.

As I’ve written previously, the existence of “chronic Lyme disease,” a condition that some claim is a set of vague symptoms that are claimed to be a consequence of a permanent B. burgdorferi infection and somehow persists after antibiotic therapy. The existence of chronic Lyme disease is not supported by robust scientific evidence published in peer-reviewed, high-impact-factor biomedical journals.

Not real scientists not working on the Lyme disease vaccine.

The first Lyme disease vaccine

The only FDA-approved Lyme disease vaccine, LYMErix, was developed by SmithKlineBeecham (known now as GlaxoSmithKline) and introduced to the US market in 1998. Patients were given a three-dose series of the vaccine over a few months.

The vaccine worked uniquely – it stimulated antibodies that attacked B. burgdorferi bacteria in the tick’s gut as the tick was feeding on the human host. Thus, the bacteria were attacked before they were able to enter the human body. It was about 78% effective in preventing Lyme disease after all three doses were given. Better yet, the vaccine was also shown to be nearly 100% effective at preventing asymptomatic cases of Lyme disease, where an individual would get the disease and develop antibodies against it but never develop any symptoms.

In 2002, SmithKlineBeecham withdrew the vaccine from the market, and Pasteur Mérieux Connaught, who also had a Lyme disease vaccine, decided to withdraw its application to the FDA, despite showing safety and effectiveness in a Phase III clinical trial.

Because I want to focus on the potential of the Valneva-Pfizer Lyme disease vaccine, you can read about what happened to these other vaccines about 20 years ago in my other article on this topic. It’s the same old anti-vaccine bad science story, in case you’re wondering.

The Valneva-Pfizer Lyme disease vaccine

Without a doubt, we need a Lyme disease vaccine, because the infection is debilitating and takes some significant effort by medicine to diagnose and treat the disease. According to a Nature editorial,

It may go against the scientific grain for marketing considerations to play such a part in steering vaccine development. But in the real world, this may be unavoidable. Lyme disease is a serious illness and those who live in areas where it is spreading deserve a vaccine.

Luckily for those in areas with endemic Lyme disease, a small French vaccine company, Valneva, has been developing a new Lyme disease vaccine, code-named VLA15. According to Valneva’s website, VLA 15 is a multivalent vaccine that targets one of the most dominant outer surface proteins of Borrelia. Valneva has partnered with Pfizer to complete clinical trials and to bring the vaccine to the market in North America and Europe.

Preclinical studies showed that the vaccine was broadly effective against Borrelia. These types of studies are how most vaccines are developed, by trying them in animal models.

Soon thereafter, Phase 1 clinical trials, in which the vaccine is tested on healthy volunteers, were successful.  Valneva proceeded with two Phase 2 clinical trials.  

According to the National Institutes of Health clinical trial database, which tracks all clinical trials across the world that must be registered through the FDA, there are two Phase 2 clinical trials underway for VLA15:

  • A randomized, observer-blind, placebo-controlled, multicenter Phase 2 study which will include 570 patients, ages 18-65 has been completed. At least this study will satisfy those anti-vaxxers who whine complain constantly about the lack of placebo controls in many vaccine studies. Because this new Lyme disease vaccine lacks any antecedent vaccine (it’s off the market), it is ethical to run a placebo-controlled study. The study was done in Stamford, Connecticut (USA), Binghamton, Rochester, and Endwell, NY (USA), Warwick, RI (USA), Ghent, Belgium, and Berlin and Hamburg, Germany. 
  • A second randomized, observer-blind, placebo-controlled, multicenter Phase 2 study has also been completed – this one examined the vaccine schedule, another important consideration (and will probably be used as evidence by the CDC to establish a schedule for the vaccine). This study included 250 patients, ages 18-65, and was located in Stamford and Milford, CT, and in Rochester, Binghamton, and Endwell, NY. 
  • The third study examined different adjuvants to determine whether they provided a better response than vaccines without adjuvants. It included 180 patients in California and Belgium. It was completed in 2019.

Valneva has reported that the Lyme disease vaccine candidate was immunogenic across all dosages. They also found that the results did not indicate that prior exposure to Lyme disease had an impact on immunogenicity or safety.

The seroconversion rates (SCR) ranged from 85.6% to 97%. The immunological response in older adults, one of the main target groups for a Lyme vaccine, is particularly encouraging, stated the company.

Now, as I’ve written extensively regarding the rush for a coronavirus vaccine, we should reserve any optimism until the results are published in a peer-reviewed journal. And seroconversion does not necessarily mean immunity, although it would strongly indicate that.

VLA15 was granted a Fast Track designation by the FDA in July 2017. Because this designation is often misunderstood, I’ll try to explain it. Fast Track is granted by the FDA to investigational products that are under development for serious conditions and have the potential to fulfill an unmet medical need (in other words, the Lyme disease vaccine is a perfect example).

The process facilitates clinical development and expedites the review of new drugs and vaccines. It accelerates the availability of promising products on the market.

This does not mean that the vaccine gets less than a thorough review. It does not mean that Valneva and Pfizer can skip any of the phases of human clinical trials. Fast Track speeds up the review process. The process does not become easier.

At this time, Valneva and Pfizer have not posted any information about a phase 3 clinical trial on the clinical trials database for the vaccine. In the non-COVID-19 world of vaccine development, usually, the FDA reviews phase 2 data before a company proceeds with phase 3. This allows for both the agency and the sponsoring company to thoroughly vet the data to make sure there are no anomalies that may cause either to tap the brakes on phase 3.

Apparently, Valneva and Pfizer have submitted phase 2 clinical trial results to the FDA and are awaiting the go-ahead for phase 3. At that time, the clinical trial will be posted on the website. You may be able to contact one of the investigators to be included in the phase 3 trials, although you may end up in a placebo group. However, if you are, and if the vaccine shows strong safety and effectiveness in the phase 3 trials, the placebo group will be unblinded and will have an opportunity to get the vaccine. The researchers probably will only include test subjects who live in areas where Lyme disease is endemic such as the northeastern and midwestern parts of the USA and Ontario, Quebec, and the maritime provinces of Canada.

Phase 3 trials usually take two or three years, though if data is strongly positive in phase 3 studies, it could be speeded up. I know we are all spoiled with the speed of the COVID-19 vaccines, but that’s not normal, unfortunately.


  1. Imagine the response from anti-vaxxers if the CDC added the vaccine to the recommended schedule – Twitter might break from all of the nasty comments. At this time, Lyme disease is most prevalent in the Northeast along with the mid-Atlantic and upper Midwest along with many areas in Northern Europe. However, there have been reports of Lyme disease outside of these, since the Ioxedes tick has been found outside of the traditional Lyme disease areas, putting these areas at risk of outbreaks of the disease. 


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