only one vaccine versus Lyme disease is currently under study. Developed by Valneva and PfizerVLA15 set to be tested in phase 3 clinical trials over 6,000 volunteers, from the age of 5, from the United States and all over Europe (50 participating sites in total). The objective is to test the efficacy and safety of VLA15 in comparison with a placebo.
The volunteers will receive three doses of VLA15, dosed at 180 µg, or a placebo at 0, 2 and 9 months. Following this first series of immunization, a booster dose will be administered 12 months after the last. To certify the effectiveness of the VLA15 vaccine, doctors will monitor the appearance of Lyme disease in vaccinated and unvaccinated people.
Results expected at the end of 2024
The Lyme disease is caused by bacteria Borrelia burgdorferi, transmitted by ticks of the genus Ixodes. The VLA15 vaccine is a multivalent vaccine with subunits proteins, i.e. it does not contain any infectious agent but protein expressed by it synthesized in the laboratory. VLA15 makes it possible to form a immunity specific to the OspA protein, present on the surface of Borrelia burgdorferi, which neutralizes it. Without it, the bacteria cannot be transmitted from tick to the human being during the bite. Valneva and Pfizer hope to obtain the final results of this clinical trial in December 2024.
Lyme disease affects more than 100,000 people a year in Europe and 400,000 in the United States. According a recent studycases have exploded 375% in rural America and 65% in urban areas over the past 15 years.
Towards a promising vaccine against Lyme disease
Article published on August 9, 2020 by Julie Kern
A French company of biotechnology leads clinical tests on a vaccine to prevent Lyme disease. It recently released early results from Phase 2 of its ongoing clinical trial and they are promising.
The biotechnology company Valneva, whose core business is the creation of vaccines against infectious diseases, has been working on a solution against Lyme disease for several years. This bacterial infection, caused by the bite of a tick of the genus Ixodes infected with a bacterium of the genus Borrelia, is difficult to diagnose. Erythema migrans, a red skin spot that extends around the tick bite, is not systematic. Others symptomssuch as fatigue, fever where the pains joints and muscles, may go unnoticed.
Moreover, it is a disease poorly understood by the population, 35% of French say they have never heard of it, according to Santé Publique France. As a result, the diagnosis of Lyme disease often falls late when joint or neurological complications are already advanced. There are approximately 50,000 cases diagnosed in France each year.
For the moment, the prophylaxis of Lyme disease is only based on prevention against the bites tick and its extraction in the event of a bite, antibiotic therapy being useless for this infection. Another solution could be vaccination. The first results of phase 2 clinical trials of Valneva’s vaccine, VLA 15, have just been shared in a Press release of the company. According to them, the vaccine candidate is effective and without severe side effects.
VLA 15, a vaccine with an unusual principle
VLA15 was tested against a placebo on 572 healthy adults in Europe and the United States aged between 18 and 65. Two doses were tested, 135 µg and 180 µg, with, for each, three injections spaced 28 days apart. L’immunogenicity was established by a dosage anti-OspA IgGs. According to these initial results shared by Valneva, the doses are immunogenic and without severe risks. The seroconversion rate is between 85.6% and 97% for the 18-49 age group. The press release also indicates that the vaccine is immunogenic in the oldest people, who are particularly affected.
The VLA15 vaccine protects against six serotypes of Borrelia burgdorferiI’species responsible for Lyme disease in Europe and North America, according to a rather special mechanism. Indeed, after vaccination, the immune system will produce antibody directed against the bacterial lipoprotein OspA. This lipoprotein is present in large quantities on the surface of the bacterium when it is in the intestine of the tick.
Thus, when the tick bites, it ingests the antibodies resulting from the vaccination and the bacteria will be neutralized in the body of the tick.mite. This vaccine process against Lyme disease has been known since the 90s, but no vaccine using it has yet been marketed. Valneva hopes VLA15 will be the first.
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