Hib (Haemophilus influenzae type b) has all but been eliminated in the UK so who or what should take the credit?
According to the UK’s Public Health Laboratory, the laurel wreath should go to an effective vaccination programme. Certainly, the rates of Hib have fallen dramatically; in both 1994 and 1995, only one case a year was reported in Oxford where 63 cases were previously reported every year. Similarly, just eight cases of Hib in children under the age of 5 from five other regions were seen in the nine months from October, 1994, compared to 270 and 269 cases in similar periods in 1990 and 1991.
So successful has been the campaign, say the experts, that no booster shot is needed when the child is aged 2.
Unfortunately, there is one niggling statistic that deserves to be heard. Of the 164 cases reported in the year from October 1992, 43 were true vaccine failures and, of these, 31 had had the prescribed three shots.
So is the vaccine really so effective after all or is medicine trying to take credit for a cyclical downturn in a disease, as other experts have suggested (The Lancet, 1997; 349: 1197-1201).
A similar sound of back slapping can be heard in the US, where they say the statistics back up their policy of a two dose measles immunization campaign, with the second dose given at school entry.
Experts from the Mayo Vaccine Research Group reckon that 98 per cent of children had measles antibodies after two vaccinations. But, again, there are always the niggardly statistics to spoil the party. In this case, 130 children who had no measles antibodies after the first shot were reimmunized, and this time 106 of them had developed antibodies six weeks after the jab. But this left 24 or 18.5 per cent who obstinately remained without immunity. Interestingly, the age of the child seemed to affect the outcome those aged under 13 months when they had the second jab were less likely to develop antibodies (JAMA, 1997; 277: 1156-8).
For more information, see WDDTY’s Vaccination Bible.