The US introduced mass chickenpox immunisation in 1995. It is now obligatory for school entry. Many other countries, including the UK, are considering following suit.

Marc Brisson and colleagues at the UK’s Public Health Laboratory are concerned that, whilst mass immunisation against chickenpox may save some children’s lives over time, it will also reduce adult exposure, increasing the incidence of shingles in the elderly, people with insulin-resistant diabetes, and immun-odeficiency diseases like AIDS. His team have calculated that the reduction of chickenpox in the environment could lead to 21 million extra cases of shingles, resulting in 5,000 deaths across fifty years. This level of deaths is, coincidentally, almost the same as the level of US children dying from chickenpox complications.

Whilst chickenpox is self-limiting and usually a mild illness, shingles is anything but benign. An outbreak is pretty unpleasant whilst running its course, but can leave sufferers with a disablement like facial paralysis, hearing loss, or permanent blindness and pain.

• Marc called for a full review of mass chickenpox immunisation.

• Vaccine manufacturers are proposing a new vaccine against the shingles their chickenpox vaccine will lead to

Ed.- (i) When a child catches chickenpox, the virus remains in the body for life, dormant in most but reactivated in some to cause shingles. Reactivation can be caused by (e.g.) physical or mental stresses, certain medications (like steroids), chemotherapy and radiation (including, of course, radiotherapy). Marc hypothesises that subsequent exposures to chickenpox virus reinforce dormancy.

(ii) There is no real case for mass vaccination. Generally, chickenpox is a mild illness. Pneumonia and encephalitis are rare complications. It can also be deadly in persons who have leukaemia or other diseases that weaken the immune system. Care must be taken that the rash does not become secondarily infected by bacteria.

(iii) A study of 461 adults who had taken part in trials of chickenpox vaccine 1979-99 found that it gave an average 91% protection against chickenpox for at least three years.
But see also Chicken pox jab only 40% effective.