Lyme Disease Explained: Causes, Symptoms and New Vaccine Breakthrough

Pfizer–Valneva Lyme Disease Vaccine Shows Promise Amid Rising Cases

Lyme disease has gained renewed global attention after Pfizer and Valneva reported over 70% efficacy for their experimental vaccine in late-stage trials, signalling progress in controlling this growing health concern.

About Lyme Disease

Lyme disease, medically termed Lyme borreliosis, is a bacterial infection caused by Borrelia burgdorferi. It affects multiple body systems, including the skin, joints, heart and nervous system. First identified in 1976 in Lyme, the disease is now prevalent across North America, Europe and parts of Asia.

Transmission and Spread

The infection is transmitted through the bite of infected deer ticks, also known as black-legged ticks. These ticks thrive in wooded, grassy and bushy areas, often attaching to humans unnoticed. Lyme disease does not spread through person-to-person contact, air, food or water, and insects like mosquitoes and fleas are not carriers.

Symptoms and Disease Progression

The disease typically develops in stages. An early hallmark sign is a circular red rash, often resembling a “bull’s-eye” pattern. Initial symptoms include fever, fatigue, muscle pain and swollen lymph nodes. If untreated, the infection may progress to serious complications such as joint inflammation, cardiac issues and neurological disorders.

Treatment and Prevention

Lyme disease is generally treatable with antibiotics, especially when diagnosed early. Delayed treatment may lead to persistent symptoms and prolonged recovery. Preventive strategies include avoiding tick-prone areas, wearing full-body protective clothing and removing ticks promptly to minimise infection risk.

Exam-Focused Points

• Cause: Borrelia burgdorferi (bacterium)

• Transmission: Bite of infected deer/black-legged ticks

• Key symptom: Bull’s-eye rash (erythema migrans)

• Regions: North America, Europe, Asia

• Not spread by: Air, water, food, or human contact

• Vaccine: Pfizer–Valneva candidate shows ~70% efficacy