Sunday, September 22, 2013

Honouring the Lie

The expression 'honouring the lie' was used by a friend a few weeks ago, and it ties in very neatly with the extraordinary claims surrounding widespread vaccination of badgers with BCG.

We won't repeat ourselves with the background to all this, which started here (link) in 2010 with an amazing headline from the BBC.
Progress of a sort was made last year (link) and the '74 per cent' was quietly reduced to 54 percent. A fair drop. And remember that this was on pre screened, non infected badgers. Not an indiscriminately trapped hotchpotch with just under half (FERA's figure for badgers excluded from the headline 844) already positive to three diagnostic tests for zoonotic Tuberculosis.

 Unfortunately those headlines in 2010 are still wafting around, still stacked as 'science', still believed,(link) and used to hoover up funds. So if they don't believe us, and think vaccinating badgers for zTB is like vaccinating children for measles, perhaps the Wildlife Trusts should take note of the EFRA Comittee's report on vaccination published earlier this year (link) where they spell out some of the points which we have made:
45. As with the 2010 study, the higher figure from the 2012 work (76%) is widely quoted[74] despite the more sensitive and specific test showing the effect of vaccination was to reduce the risk of a positive result to the lower figure of 54%. In order for vaccination to be considered part of a strategy to eradicate bovine TB we first need to establish what level of efficacy can be expected.
Precisely. To license this product, no efficacy data was produced: so it's no use the little poppets waving their collecting boxes and bleating that 'If it didn't work, it wouldn't have a license'. It does. But BCG for badgers  has a ' Limited Marketing Authority'  (LMA) license only. Which in the Veterinary Medicines Directorate's  (VMD) own words, means that "efficacy data is limited" and "the applicant must demonstrate the benefits outweigh any risks".

Crucially VMD state:
"Decisions as to whether the vaccine is suitable for use in a particular situation are outside the VMD's statutory role [snip ] and are the responsibility of the end user".
But back to the EFRA report which echoes those eerily silent squeaks from Defra when the headline of '74 per cent ' was launched, and in the two years since then. The EFRA report notes, amongst other points, that launching BCG into an endemically infected population of badgers, (as is being done now), may just make things a whole lot worse for many years longer:
62. [] However, it remains the case that vaccination does not remove and has no effect on already-infected badgers. Indeed, mitigating the effect of the disease through vaccination may increase the survival time of carriers and secretors.[98]
This nails the misconception that a single jab of BCG vaccine will prevent tuberculosis in the first place. It will not. If it works at all, and in almost half the pre screened candidates vaccinated with BCG, the vaccine does not work, it reduces the size of lesions and thus some of the bacterial spread from them.
But tuberculosis is still there. So badgers will have a little bit of 'tuberculosis' - as in be a 'a little bit pregnant'? They still have lesions and still spread bacteria. As EFRA correctly point out.
63. Benefits from vaccination would be expected to accrue incrementally over several years as the number of badgers vaccinated increased and infected badgers died off. Although, according to Defra, most individual badgers already infected with bovine TB will die off within five years, it is likely that annual vaccination would need to last many years more to be successful.[99]

For vaccination to produce herd immunity, a significant proportion of badgers need to be captured. The Carter et al research suggested that vaccination reduced the risk of a positive test result by 54% in vaccinated individuals.

However, if only 50% of badgers were trapped and vaccinated with a vaccine that is 54% effective then just a quarter of the badger population would have a reduced risk of infection - and that is assuming that those vaccinated were not already infected.

The more endemic the disease the more difficult it will be and the longer it will take for vaccination to be effective.[100]
Quite. A lot of 'ifs' there, and many assumptions of current disease status, trapping rates and vaccine efficacy.
So why are the Wildlife Trusts, Badger Trusts and Uncle Tom Cobley Brian May and all,  still ratting on that indiscriminate vaccination of an endemically infected badger population, will zap zoonotic Tuberculosis in the population, within 5 years - for ever?

And have you noticed that all this raises it's head in the middle of yet another consultation (link) on culling badgers?

And that really is 'Honouring the Lie'.

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