Re: Re: Further to Peter Flegg and the TB ref.
Mr Flegg wished to discuss BCG, and considers this vaccine
worthwhile, at least in terms of complications and mortality, so I would
value his input on the following:
Has Mr. Flegg read the most recent Indian trial of 366,625 people
published in the Indian Journal of Medical Research, 1999; 110:56 which
also found the BCG vaccine to be useless? If so, what did he think of it?
Has Mr. Flegg also read the Malawi Lancet study, March 14, 1992,
Pages 636 - 639 which said in the abstract: "There was no statistically
significant protection by BCG against tuberculosis in this population.
These findings add to the evidence that BCG vaccines afford greater
protection against leprosy than against tuberculosis."
Has Mr. Flegg also read the research led by Dr Annelies van Rie of
the University of Stellenbosch in Tygerberg which found that people
subsequently recovered from one TB infection, could acquire a new one,
because strains in any country appear to change quite quickly.
Has Mr Flegg also read the editorial in the same issue of the New
England Journal of Medicine (1999), in which he says:
>>>>" If natural infection does not confer protective
immunity... the development of improved vaccines against tuberculosis will
be especially challenging."<<<<
Paul Fine also says in "Epidemiologic Reviews", 1993, Volume 15,
Number 2 page 294:
>>>>>>>>"natural immunity to tuberculosis is
general associated with persistent, rather than self-limited infection...
.....There has been little discussion of herd immunity with reference
to tuberculosis. A major reason for this silence is the rudimentary level
of our understanding of the nature and implications of either natural or
vaccine derived immunity to this disease.... there is no convincing
evidence that the use of BCG vaccines has reduced the risk of infection
with the tubercle bacillus in any population In the absence of greater
basic understanding of the nature and implications of the immune response
to tuberculosis , it is of questionable utility to ponder its theoretical
Mr Flegg has admitted that herd immunity isn't a consideration but I
am puzzled why Mr Flegg considers vaccination of UK infants of much use in
the context of the above.
As far as I know, the "understanding" of the medical profession on Mr
Fine's points has not progressed that much further. Research appears to
focus on more financially rewarding aspects of TB... like DNA vaccines,
Could Mr Flegg comment on the above please in connection with the
best way to assist both AIDS patients, immigrants and the UK population at
Has the infectious diseases unit which Mr Flegg is associated with
made sure that the "importing" strains of TB into the UK are all DNA
characterised, so that that can that be taken into account when chosing an
In reference to Mr Flegg's comment that he cannot recollect any
studies where BCG was shown to be worse than ineffective in India, there
is another study I would like his comment on.
It is one of the several studies which the USA did, upon which it
decided NOT to use the BCG vaccine at all.
Contrary to Mr Flegg's suggestion that the USA didn't use the vaccine
because their TB levels were low, and they wanted to be able to use skin
tests of reactivity to tuberculin for diagnostic purposes, I find that the
USA would have used the vaccines had any of their studies showed solid
demonstrable benefit. None did.
Looking that the USA's historical statistics of TB deaths and
incidence, they appear pretty much as anywhere else in the world. I can't
find any evidence that the two reasons stated by Mr Flegg are really
Had there been such a low level of TB there, as alleged, why would
the USA have bothered with any trials at all? It is hard to escape the
conclusion that the principle reason for the non-use of the BCG in the USA
was simply because the vaccine was of no benefit. And yes, in that
context, it would very clearly blur the ability to diagnose any actual
The particular study Mr. Flegg's comment is asked for, was reported
in AJPH March 1974, Volume 64, No 3, pgs 283 - 291. It was called
"Evaluation of BCG vaccination among Puerto Rican Children", in which a
total of 191,827 were included in the study population in which the result
was that the overall reduction in tuberculosis was less than 9 percent.
There is an interesting comment on page 291, which says:
"...it is particularly tragic that the use of scarce resources to
administer BCG must still be based on blind faith."
As an offshoot of this study, the same population was reported on in
a second study called "Efficacy of BCG vaccination in prevention of
Cancer: An Update : Brief communication." J. Natl Cancer Inst: Volume 60
No 4, April 1978 pages 785 - 788.
The comment made on page 785 is:
"Although no statistically significant protective effect of BCG could
be demonstrated, the vaccinated group had a slight deficiency of leukemia
cases and an excess of lymphosarcoma and Hodgkins disease."
Given that Mr Flegg says that the resumption of the UK vaccine
programme is in part due to an influx of people from high TB prevalence
areas (immigrants) and given that these are exactly the countries where
the TB vaccine appears not to work... and given that it appears that
strains vary hugely, even within one country, how does Mr Flegg believe
that the use of "whatever" BCG vaccine will assist the general British
And can he guarantee that the use of BCG vaccines will not increase
the rates of certain cancers as in the Puerto Rican study, or have any
other unforeseen impact to children, in the future?
And given that a Finnish study (Am J Epidemiol 1999, Sep 15; 150(6)
632-641) showed that there is a lower tuberculosis incidence in subjects
who consume more fruits vegetables and berries, and that they found a
highly statistically significant inverse association between calculated
vitamin C intake and the incidence of tuberculosis, what is that he, as an
expert in infectious diseases, and infection, proposes to suggest to the
UK population, as well as these immigrant people at high risk of
tuberculosis as their best method of bolstering natural resistance?
I ask this, because my points raised above on "Nutrition, infection
and immunity" also appear to have gone unanswered, which, given Peter
Flegg's qualifications, I now find a strange omission.
Given the the admittedly complex nature of the BCG debate, and such
uncertainty over which strains are in what BCG vaccine, it would seem to
me that the issues of nutrition and their relevance to diseases, natural
immunity, immune mechanisms and host responses might be worth a closer
Mr Flegg's expert comment would be welcomed.
Competing interests: No competing interests