Vaccine update: hiv, polio, flu

Three vaccines against HIV infection are to be tested on children in the US. Ninety healthy HIV infected children aged between 1 month and 12 years are to be recruited to the study (The Lancet, 3 April 1993).

The current schedule of three doses of the oral polio vaccines is not adequately protecting children, according to an Indian study (The Lancet, 3 April 1993).

In the town of Vellore, even though virtually all (98 per cent ) of its children had had three doses during 1991 and 1992, and 90 per cent had four doses in 1992, the disease has failed to go away. "In 1991 and 1992, six fully immunized children developed poliomyelitis, for a mean annual incidence of 1.4 per 100,000," said the researchers. They blame "suboptimum vaccine efficacy and inadequate herd effect". The solution? Up the schedule to seven doses.

Some flu vaccines can lead to a false positive diagnosis of HIV infection. In the US, 10 people who gave blood during a month and a half at the end of 1991 were wrongly diagnosed as having two or more of the following viruses: HIV, HTLV-I, and hepatitis C (JAMA, 28 April 1993). All had earlier been given a flu jab, from the batch of vaccine formulated for the 1991-92 season.

On the subject of flu vaccines, a Leicester based study (BMJ, 10 April 1993) found that almost a third of those having the jab didn't need it. They had none of the underlying factors chronic cardiovascular, pulmonary or renal disease, or diabetes supposedly placing them at greater risk. Of those who really could have used the jab, less than half had been immunized.