Zoster vaccine still produced responses during intravenous cyclophosphamide

Design

Sub-analysis of a prospective randomised placebo-controlled trial

Population

41 rheumatic disease patients on IV cyclophosphamide, 164 not on it, 164 healthy controls

Primary outcome

Humoral response after two doses

Effect

Seroconversion 91.9% vs 91.5% vs 99.4% in controls

This sub-analysis of a randomised, placebo-controlled trial compared the recombinant zoster vaccine in 41 patients with autoimmune rheumatic disease receiving intravenous cyclophosphamide, 164 patients with rheumatic disease not on it, and 164 healthy controls. Everyone received two doses.

Seroconversion was 91.9% with cyclophosphamide and 91.5% without, against 99.4% in controls. Antibody titres were similar between the two patient groups but lower than in controls. Cellular responses and disease flares did not differ, and there were no serious adverse events.

Cyclophosphamide was expected to blunt vaccine response heavily, which is why many clinicians defer vaccination. This small study suggests that is not necessary for the recombinant vaccine, though it measured immune response, not shingles prevented.

• Consider offering recombinant zoster vaccine to patients on intravenous cyclophosphamide rather than deferring it
• Use only the recombinant, non-live vaccine in immunosuppressed patients; live zoster vaccine is contraindicated
• Give both doses and record the schedule clearly
• Check local availability and cost, which limit access in India

Why it matters

It removes a common reason for postponing protection in patients at high risk of shingles.

Don't overread it

Antibody response is a surrogate; the study did not measure how many cases of shingles were prevented.

The statistics, in plain English

Seroconversion means a fourfold or greater rise in antibodies. Rates of 91.9% and 91.5% are effectively the same, though with only 41 patients on cyclophosphamide a modest difference could have been missed.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.