Lyme Disease Vaccine Candidate VLA15 Advances Through Phase 1 Trials


Valneva, a French biotech company focused on developing vaccines, has announced it has obtained successful Phase 1 results for its Lyme disease vaccine candidate, VLA15 [1]. The Food and Drug Administration (FDA) approved a Fast Track designation for VLA15 in 2017 due to the increasing severity of Lyme disease. Therefore, the vaccine candidate will be given priority at every step of the licensing process [2]. Phase 1 of the clinical trial aimed to evaluate the safety and tolerability of VLA15. It is expected to enter Phase 2 clinical development by the end of 2018, to test efficacy of the vaccine [1].


Lyme disease is a vector-borne disease spread by ticks carrying the bacterium Borrelia burgdorferi [3]. Unlike many bacterial infections, it is found in the body’s tissues rather than circulating in the blood, making it more difficult to detect and treat [2]. Symptoms include fever, headache, fatigue and skin rash, all of which can usually be treated with antibiotics. If left untreated, the infection can spread to the heart and the central nervous system. Lyme disease is considered the most common vector-borne disease in the Northern Hemisphere and the burden of the disease is growing each year. The World Health Organization (WHO) estimates that there are 532,125 cases in the world annually [4].


The VLA15 vaccine targets the outer surface protein A (OspA) of Borrelia burgdorferi. It confers protection by creating antibodies that prevent Borrelia from migrating from the tick to the human after a bite occurs [1]. VLA15 protects against the majority of human pathogenic Borrelia species. The target population includes individuals over two years of age living in endemic areas or those planning to travel to endemic areas. Study subjects in the Phase 1 trial were given the vaccine three times, each one month apart. This is the likely number of doses that will be needed to confer immunity, pending the remaining trials[1].


To date, there has only been one other licensed Lyme disease vaccine on the market, from 1998 to 2002. This vaccine, called LYMERix, was given in a three-dose series and was 78% effective in protecting against infection after all three doses [5]. Shortly after the vaccine arrived on the market, several reports were made of serious adverse events, as well as cases of arthritis believed to be caused by the vaccine. Simultaneously, many people were growing suspicious of vaccines, particularly fueled by the now-retracted Lancet study that falsely claimed that the measles, mumps and rubella (MMR) vaccine was linked to autism [6]. The cases of arthritis combined with anti-vaccine media and lawsuits caused the vaccine to be withdrawn from the market. Though official safety data did not show a difference in chronic arthritis between those who received the vaccine and those who did not, public concern ultimately carried the most weight [5].


Until now, there have been no other attempts to develop a new human Lyme disease vaccine, in part due to this failure of LYMERix in the eyes of the public. More than a decade after the first and only vaccine was withdrawn from the market, Valneva has placed priority on the increasing incidence of Lyme disease in the United States and worldwide, in the face of the modern anti-vaccine movement.











Related Posts