In 1992, immediately following a then new vaccination against Haemophilus influenzae type b (Hib) infection, my two year old granddaughter became unresponsive and regressed until she lost all understanding and speech.

She was finally diagnosed with the extremely rare childhood disintegrative disorder Heller's syndrome.

An Australian National Health and Medical Council information sheet on Hib vaccines advises that Hib meningitis can cause brain damage with laterlearning difficulties and behavioural disorders (www.health.gov.au).

On hearing of US reports of an elevated risk of Hib disease in the week following Hib vaccinations, I sought as much information as possible. Through the US Freedom of Information Act (as WDDTY suggested), I was able to obtain adverse reports for 1988-90, when the vaccine given to my granddaughter was first used in the US.

The reports showed clustering of meningitis on day two following vaccination, with an unexpected

involvement of the MMR vaccine.

There are 140 serious outcome reports, with 24 cases of meningitis. Five meningitis cases occurred on day two following vaccination and one on day four; nine are classed as 'no drug effect' and nine had undefined timing. The 'no drug effect' cases must be vaccine failures, occurring at least a month, but up to two and a half years, after vaccination.

If the five day two meningitis cases represent 'background' disease, there should have been comparable reports for all seven days of the week following vaccination. It seems most unlikely that 'background' disease cases could be so concentrated on day two.

Seven of the 140 serious outcome children also received MMR vaccine, probably representing those who missed this shot at one year of age. Three of these seven children had day two meningitis. It is most unlikely that the involvement of MMR in day two meningitis is a chance occurrence.

If no one can say which brain damaging illness caused a particular child's autistic regression, greatest suspicion must fall on the most common illness with features consistent with parents' experiences. BG, Canberra