Monday, July 18, 2005

Speaking of anti-science idiocy

Ron Law who appeared on the close up program mentioned in the previous post, published this article along with journalist Barbara Sumner Burstyn. In their press release they claimed there was an increase in the risk of meningococcal infection in preschoolers as a result of the vaccine. This is an amazing example of their general ignorance and that they do not understand the science behind what they are claiming.

Firstly, the study did find that the vaccine they had given was ineffective in toddlers, for two doses. Studies that were conducted and used three doses found that the vaccine worked very well and was highly effective; from the paper in question
Infant participants in the Tappero et al. study were given three doses of either the NIPH, or the FI, or a control vaccine.12 After three doses, 98% and 90% of infants who received the NIPH or FI vaccine, respectively, were seroresponders against their vaccine strain (homologous strain); that is, they demonstrated a fourfold or greater rise in serum bactericidal antibody levels. Seroresponse in infants to strains other than the vaccine (heterologous strain) was poor. Tappero et al. noted that for the FI vaccine recipients, the percentage of seroresponders almost doubled from dose two to dose three, and that had the participants in the Sao Paulo study19 been given three doses, the efficacy of the vaccine may well have been found to be much higher. The New Zealand clinical trials are being conducted using three doses of vaccine, and the use in younger age groups of a fourth dose (if needed) has not been ruled out.

There is a very large body of applicable safety data on group B OMV vaccines that provides considerable reassurance that an OMV vaccine against the New Zealand strain,
although reactogenic, will be safe in all age groups.
Which is a very different tune than the claims Ron Law is trying to sell you. Of course, if Ron Law wasn't being disengenuous to begin with you'd realise there isn't any issue to make anything out of here, unless we take something horrifically out of context. The only significant finding that we can take from Ron Law and Barbaras distortion is that neither of them understand statistics! The first problem with their analysis is they try to posit that the confidence interval in the graph indicates that the children in those groups have increased sensitivity. This is not at all the case. If a confidence interval passes zero (IE goes negative) as it does in the presented graph, it does not mean that there is an increased risk, it means there is a strong indication of a lack of efficiency but not of increased disease.

Such elementary mistakes from people who are supposedly 'informed' about their crusade against the MeNZB campaign speaks volumes of their credibility.

Study cited:
Sexton K., D. Lennon, P. Oster, S. Crengle, D. Martin, K. Mulholland, T. Percival, S. Reid, J. Stewart and J. O’Hallahan (2004). The New Zealand Meningococcal Vaccine Strategy: A tailor-made vaccine to combat a devastating epidemic. New Zealand Medical Journal, 20-Aug-2004 - Vol 117 No 1200