Safety, immunogenicity, and efficacy of Borrelia burgdorferi outer surface protein A (OspA) vaccine: A meta-analysis.

INTRODUCTION Lyme borreliosis, caused by Borrelia burgdorferi sensu stricto in the United States and by several Borrelia species in Europe and Asia, has a great impact on the health of the global population. There are human vaccines available, such as the outer surface protein A (OspA) vaccine, but still more evidence is needed to verify its function. We investigated the safety, immunogenicity, and efficacy of adjuvanted or non-adjuvanted vaccines containing protective epitopes from Borrelia species OspA serotypes in healthy adults. METHODOLOGY Seven electronic databases were searched for clinical trials involving vaccine of OspA, with outcome data on safety, immunogenicity, and efficacy. The meta-analysis method was used to compare all vaccination strategies at the same time. RESULTS Three relevant studies were identified. All were randomized controlled trials (RCTs) or quasi-RCTs. Meta-analysis shows that, compared with low dose, high dose comes with a higher IgG titer with overall effect size of 6.39. For the 30 µg dose, the geometric mean titer was 6918.31, which is statistically significant when compared with 0. With respect to safety, only soreness showed a relatively high incidence of 40% (p < 0.05 when compared with 0, while the other side effects were no difference compared with 0). CONCLUSIONS The OspA vaccine against Lyme disease is safe and its immunogenicity and efficacy have been verified. Instead of stagnating or giving up, further research on improving the vaccine is needed. On the foundation of preliminary studies, we can attempt to develop new vaccines for human use.