By: Paul A. Offit, MD
First, immunity does appear to decline after 5 years, earlier than had been suspected. Secondly, if you look at vaccine effectiveness, within a year of getting the vaccine, it’s in the low 90% range, within 1 to 2 years of receiving the vaccine, it’s also in the low 90% range, but when you look between 2 to 5 years after vaccination, although the numbers are fairly low and the confidence intervals are wide, it looks like the protection drops into the low 50% range.
Similarly, some evidence for herd immunity was expected, as had been seen for the conjugate Haemophilus influenzae type-B vaccine and the conjugate pneumococcal vaccine, but that didn’t appear to be happening. It appears that the vaccine is protecting only those who are vaccinated and not extending beyond that group. For that reason, members of the Advisory Community for Immunization Practices (ACIP) considered at their last meeting in October whether they should change the recommendation, and they did.
(Note from SaneVax: Just so everyone is on the same page here – this clearly states a vaccine that was marketed as lasting ten years only lasts five. The often cited ‘herd immunity’ does not apply, at least to this particular vaccine.
Was there any discussion about improving the efficacy of the vaccine? No. Was there any discussion about how severe a threat meningitis poses? No.
Was there any discussion about what genotype of meningococcal bacteria caused the few cases reported? No.
Was there any indication that the vaccine recommended for booster shots was relevant to the genotypes causing meningitis? No.
The recommendation was just to increase the use of a vaccine that is clearly not functioning as intended. What is wrong with this picture?)