Chickenpox may be a childhood memory, but the virus never leaves. It lies dormant in nerve cells and can return decades later as shingles, a blistering rash with nerve pain that can linger long after the rash fades. In this episode, host Pushpa Narayan, a senior editor with TOI, speaks to Dr Subramanian Swaminathan, president of the Clinical Infectious Diseases Society of India.

Dr Swaminathan explains why the varicella zoster virus reactivates, and why one in three people will get shingles in their lifetime — age, diabetes, cancer treatment, steroid use, organ disease and HIV all raise the risk. Early shingles pain can be mistaken for a heart problem, dental trouble, or appendicitis, and starting antivirals early can ease the rash and reduce pain severity afterwards. He also covers rare but serious complications, including spread to the lungs and brain, and a higher risk of heart attack and stroke in the months after infection.

The conversation also addresses whether shingles is contagious, how it differs from other herpes viruses, and why a blood test before vaccination adds no value. The episode ends with a clear case for the two-dose shingles vaccine from age 50.

Chapters:

00:00 – Introduction: the chickenpox virus that returns as shingles

00:48 – Why chickenpox comes back: the “Mexican standoff” with the immune system

01:58 – Who gets shingles: one in three, and the role of age and illness

03:03 – What happens in the body: a dormant virus travels along a nerve

04:21 – Spotting shingles: misdiagnosis, one-sided rash, 48–72 hours to appear

06:08 – Cost of delay and the treatment: antivirals and painkillers

07:35 – A nerve "on fire": neuropathic pain and serious complications

09:23 – ICU risk, severe disease and the heart attack and stroke link

11:00 – Is shingles contagious? Caregivers and isolation rules

12:57 – The herpes virus family and why this virus is so "smart"

15:50 – Do other herpes viruses cause shingles?

17:00 – Prevention: the chickenpox vaccine and the shingles vaccine

18:20 – Is a blood test needed before the shingles vaccine?

19:47 – Two doses, and how long protection lasts

20:47 – Why 50 is the sweet spot, and why not earlier or later

22:42 – Cost versus benefit: efficacy against shingles and pain