Novel vaccine against Lyme disease reported to be secure and effective

In a recent study published in The Lancet Infectious Diseases, researchers determine the security and immunogenicity of a novel candidate vaccine against Lyme borreliosis.

Study: Safety and immunogenicity of a novel multivalent OspA-based vaccine candidate against Lyme borreliosis: a randomised, phase 1 study in healthy adults. Image Credit: Evgeniyqw / Shutterstock.com

What’s Lyme disease?

Lyme borreliosis is a tick-borne disease that commonly occurs in North America and Europe. Yearly, Lyme borreliosis affects over 200,000 and 500,000 people in Europe and america, respectively.

Lyme disease is brought on by the pathogenic spirochetes belonging to the Borrelia burgdorferi sensu lato complex. This species comprises B. burgdorferi sensu stricto, which is accountable for serotype 1, B. garinii, which causes serotypes 3, 5, and 6, in addition to B. afzelii and B. bavariensis, which cause serotypes 2 and 4, respectively.

Lyme borreliosis manifests as erythema migrans, which is an erythematous skin lesion with incidence specific to serotypes, together with fever, fatigue, headaches, myalgia or arthralgia, and mild stiffness within the neck.

Although this disease could be easily treated with antibiotics if detected within the early stages, untreated Lyme borreliosis can affect the joints and heart resulting in oligoarticular arthritis and carditis, respectively. Neurological consequences of untreated Lyme borreliosis include facial palsy, meningitis, and radiculopathy.

The distribution of previous monovalent Lyme borreliosis vaccines was discontinued within the U.S. on account of low acceptance after concerns about potential autoimmune arthritis induction following vaccination; nonetheless, no evidence was found for this safety concern.

Concerning the study

In the current study, researchers evaluate the immunogenicity and safety of a hexavalent candidate vaccine VLA15 amongst humans after the vaccine was shown to induce long-lasting immunity in mice models.

The goal of most Lyme borreliosis vaccines has been the outer surface protein A (OspA), which is dominantly expressed by the Borrelia spirochetes within the midgut of the tick vector. The antibodies induced by vaccines against Borrelia OspA are expected to focus on and neutralize the spirochetes within the tick midgut before they may cause infections in humans.

The hexavalent VLA15 vaccine incorporates three lipidated fusion proteins, each of which link the OspA C-terminal domains of two serotypes to ultimately goal six serotypes.

All study participants were healthy adults between the ages of 18 and 40, whose seronegativity for Lyme borreliosis was confirmed using enzyme-linked immunosorbent assay (ELISA). The participants were randomly assigned to groups that received 12, 48, or 90 micrograms (µg) doses of the vaccine, with and without adjuvants.

The first objective of the study was to watch safety endpoints, which included the severity and frequency of solicited systemic and native hostile reactions, in addition to unsolicited mild to severe hostile reactions for up to at least one month after completion of the first vaccination regimen.

The solicited local hostile reactions included pain, erythema, swelling, tenderness, itching, and induration within the injection site. Systemic reactions included fever, nausea, headache, fatigue, rash, arthralgia, flu-like symptoms, and myalgia for one week after administration of the vaccine.

The secondary endpoints included evaluating hostile events at various time points after the completiong of the first vaccination regimen for up to at least one 12 months, with additional observations conducted one and 6 months after booster vaccination. Vaccine immunogenicity was evaluated based on the geometric mean titers of immunoglobulin G (IgG) against any of the six serotypes, which were measured through seroconversion rates and ELISA.

A secure and effective vaccine against Lyme disease

Primary vaccination, which involved three doses of the hexavalent VLA15 vaccine against Lyme borreliosis, was secure and well-tolerated by the healthy adult human population within the study. VLA15 also elicited significant immune responses against all six serotypes based on OspA.

Some mild systemic and native hostile reactions equivalent to tenderness and pain within the injection site, in addition to myalgia, fatigue, and headache, were observed. Nonetheless, no hostile reactions much like manifestations of Lyme borreliosis, or any evidence of systemic inflammation, including changes in biomarkers equivalent to C-reactive protein, leukocytes, or erythrocyte sedimentation rates, were observed.

Booster vaccination 13 months following the primary vaccine dose was equally secure and induced substantial anamnestic immune responses. The observed reactions to the VLA15 vaccine were typical of the hostile reactions to other lipid-formulated recombination vaccines.

Conclusions

The hexavalent VLA15 vaccine against Lyme borreliosis was found to be secure and didn’t induce any serious systemic or local hostile reactions. The vaccine also elicited significant antibody responses against all six serotypes targeted by the vaccine. Moreover, substantial anamnestic immune responses were induced by booster vaccination roughly one 12 months after the first vaccine.