Rebuttal to Wakefield Called 'Weak' with 'Distortions': Shattock
January 26, 2001
This Wednesday we posted a report from Mike Watson in the
UK which
purports to correct items in the recently released Andrew Wakefield study.
The study challenges the safety of the MMR vaccine. "A Rebuttal to
Wakefield's "Measles, Mumps, Rubella Vaccine. . ." was the newsletter item.
Paul Shattock, the Director of the Autism Research Unit,
University of
Sunderland, writes in to report his reactions and counter-rebuttals to what
he asserts are specious and even deceitful arguments by rebuttal author Mick
Watson. Watson is the Medical Director of Aventis Pasteur MSD.
"For us it is always a pleasure when the opposition
shows what it has
in terms of arguments, remarks Shattock as he removes his gloves, "it is
even better when their case is so palpably weak that they must resort to
distortions of fact that are easily detectable to even a casual reader."
Below are quotations from the Wakefield study followed by
Watson's
rebuttals. Following that are the counter-rebuttal comments from Shattock.
Wakefield: The first thing to note is that these were
short-term
safety studies with periods of observation lasting at most 28 days, and
often considerably less.
Watson: The observation period in the study that the
authors
concentrate on (Stokes et al, 1971) is clearly stated in the first page of
the paper as being "six to nine weeks". That is up to 63 days, rather than
28 days.
No parent whose child has been involved in a clinical study
will
forget this. Indeed, a sticker is often placed on the front of the child's
notes to ensure that everyone is aware of this. If the parent or a
healthcare professional perceive there have been any unusual problems in a
clinical trial subject, they are extremely likely to report it.
Shattock: No idea what this sticker business is about but
let
us quote the paper:
The abstract states, "Joint
involvement was notably absent during
the six to nine week follow-up".
On the final page comes the main
reference to this element of the
trial.
"The present studies with queries at
six to nine weeks following
vaccination did not reveal any occurrence of arthritis or
arthralgia
beyond the 28 day period for close observation."
It is so abundantly clear that the trial
was for 28 days. No data
are provided for anything over that save this particular
feature
which (quite correctly) was sought by the researchers.
Wakefield: Prior to its licensing in 1975, trials of
combined MMR
vaccine safety were the subject of two relatively small-scale controlled
studies.
Watson: MMRŽ (1st generation, Merck) was licensed in the
US in 1971
and in the UK in 1972.
Safety of MMR vaccine (from one manufacturer alone - Merck)
was
investigated in four studies prior to licensure. In addition, seven studies
(two of which are published) investigated the safety of MMRŽ II prior to its
licensure - these are not even mentioned in the paper.
The safety of another MMR vaccine, ImmravaxŽ, was studied
in seven
studies prior to its licensure in the UK.
Shattock: I am positive beyond any doubt whatsoever that Dr
Wakefield
was absolutely assiduous in seeking data. There would have
been no
point in any paper that did otherwise. It is unclear
whether these
studies were published or retained in secret files which
are not
available. We would greatly appreciate the published
citations so that
any errors can be drawn to the attention of the authors.
Wakefield: The potential for delayed intestinal pathology
is borne out
by Fournier et al's demonstration of persistent measles virus infection of
the diseased appendix in 1968.
Watson: Virologists generally accept that wild measles
virus only
causes persistent disease in the central nervous system - subacute
sclerosing panencephalitis (SSPE) and measles inclusion body encephalitis
(MIBE). MMR has been demonstrated to protect against these diseases.
No group has ever shown reproducibly by accepted methods
that measles
virus, either wild or vaccine-derived, causes persistent GI infection in
children with autism. This includes Wakefield's own group (Chadwick N, Bruce
IJ, Schepelmann S, Pounder RE, Wakefield AJ. Measles virus RNA is not
detected in inflammatory bowel disease using hybrid capture and reverse
transcription followed by the polymerase chain reaction. J Med Virol 1998;
55(4): 305-11].
Shattock: Hmm. Strange that there appears to be an
SSPE death related
to the MMR a couple of weeks back. I concede that the
Wakefield team,
in the paper quoted above, failed to isolate the measles
virus RNA.
The method used was not sufficiently sensitive and would
require a
huge infection to show up. Fortunately, it now appears that
adequate
techniques such as those employed by the Japanese and by
O'Leary have
remedied the situation. The Japanese have published.
The principal of publishing results, even
though they fail to
support your case, must be unusual in a commercial or non
investigative laboratory. Dr Wakefield and his colleagues
have
been much derided by opponents for doing this. The
principle is
called "integrity". It is an alien concept in
Departments of
Health and certain areas of commerce. This is the
area where
science is lost to political or economic requirements.
Watson: However, it is thought that mutant measles virus
genetic
material can persist in the tissues of apparently healthy people without
causing disease [Katayama Y, Kohso K, Nishimura A, Tatsuno Y, Homma M,
Hotta H. Detection of measles virus mRNA from autopsied human tissues.
J Clin Microbiol 1998; 36(1): 299-301].
Shattock: So "mutant" measles can persist but
Moraten and Schwarz
strains cannot? Those would be interesting references
(please).
Watson: Background rates of gastroenteritis in Philadelphia
and
Costa Rica-San Salvador.
These data are presented as 5.6% and 44% respectively.
However, it is
not appropriate just to sum the percentages in the gastroenteritis rows of
Tables 6 and 7 of the paper (Stokes et al, 1971) since they may result in
double counting (subjects may have reported gastroenteritis in more than one
of the time intervals). This is especially true for countries with higher
rates of enteric infections.
A similar argument pertains to the "unrelated
illnesses" referred to
later in the paper.
Shattock: Exactly the same, the same caveats apply to both
groups
equally. It is the overall comparison of the two groups
that is
important. One group (MMR) had way more GI problems than
the controls.
Please examine this for yourselves and thank you for
drawing the
casual reader's attention to this, one of the key points of
the whole.
Wakefield: Combination of the data sets [gastroenteritis in
Philadelphia and Costa Rica-San Salvador], as presented, obscured these
facts...
Watson: These data are not presented combined, but rather
separately,
in Tables 6 and 7 of the paper (Stokes et al, 1971).
Shattock: The data are indeed presented separately. There
is no
evidence, in this particular paper, that the figures from
Philadelphia
and Costa-Rica were combined to obscure the differences
seen in the
developed and undeveloped world.
In the next paper (Schwarz AJF etc 1975)
there is no attempt to
separate results from the 282 children from Daytona (Ohio)
- a
developed country and the 1192 from the undeveloped Santo
Domingo and
Panama. Given the significant differences referred to
above, this
would seem a very unscientific and unsatifactory approach.
It was also
difficult to understand why Gastro-enteritis was completely
omitted
from the list of "side effects" considered when
the differences were
so blatant.
Watson: High rates of gastroenteritis post-MMR vaccine.
The gold
standard in safety studies for common events following MMR vaccine was a
placebo-controlled crossover study of 1162 twins in Finland in 1982 - this
is not even mentioned by the authors.
More detailed data from this study has recently been
published
[Virtanen M, Peltola H, Paunio M, Heinonen OP. Day-to-day reactogenicity and
the healthy vaccinee effect of measles-mumps-rubella vaccination.
Pediatrics.
2000 ; 106(5): E62]. In this study, diarrhoea, nausea and vomiting after MMR
were reported with the same frequency as placebo.
Shattock: Was this 1982 study published? If so where?
It would have
been difficult for Dr Wakefield to quote the 2000 paper
which appeared
after his own paper had been submitted. If the results are
as you
suggest they would appear to be at variance with the
previously
published report referred to above. Checking is clearly
required.
Wakefield: Follow up for detection of adverse events was
reduced from
4 weeks in the initial controlled trial, to 3 weeks in subsequent studies.
Watson: As mentioned earlier, the observation period in the
initial
studies was not 28 days but up to 63 days.
Shattock: Again I must disagree. Observations were for 28
days only.
At the time of "the second bleeding" (up to 63
days) parents were
asked about "any significant illness". Given the
nature of the
questions and the fact that there was none for the whole 63
days, the
side-effects listed in the paper were clearly excluded.
There is no
doubt that the 28 days is accurate.
Watson: The later development studies of MMRŽII had an
observation
period of 42 days. PriorixT studies had observation periods of 42-60 days
Shattock: Publication details please! You could be right
and we
need to know.
Watson: Numerous post-marketing surveillance studies of MMR
vaccines
have been conducted and published - these are not even mentioned by the
authors.
Shattock: All that has been requested from day one is the
science
that demonstrates safety. If these numerous articles exist
why have
they not been quoted by the Department of Health and why
has no-one
been able to locate them? References please.
Summary - Watson: This review has been published in an
obscure
journal aimed at toxicologists and clinical pharmacologists. It has a
worldwide circulation of 400 copies (www3.oup.co.uk/drugsj/adrates/). It
would not have been accepted by a mainstream journal. The paper has been
widely leaked to the media but its first author would not provide Aventis
Pasteur MSD with an embargoed pre-publication copy.
Shattock: The paper was about "Adverse Drug
Reactions" so a journal
about "adverse drug reactions" would seem to be
appropriate. There
are few journals designed for such studies.
An advance copy was sent to the
Department of Health. Leakage did
nothing to help the authors' case and was unfortunate all
round. Not
only did it obscure the authors' presentation but
interfered with
the Department's own pre-emptive campaign of the previous 3
weeks.
For Aventis Pasteur to expect advance
copies of such material
when their own 30 year old research is still unavailable
for
assessment by interested parties is really a bit much.
Watson: The paper is a selective, biased and flawed attempt
to
undermine confidence in MMR.
The authors themselves concede that the contents of the
paper have no
relevance to autism.
The paper is littered with inaccuracies. The
worldwide literature on
the positive aspects of MMR safety has been totally disregarded.
No published epidemiological study has ever shown a link
between MMR
vaccine, autism and inflammatory bowel disease.
Shattock: I would invite and encourage readers to compare
the
quality of the evidence and the tone of the Wakefield paper
with that
presented by the company representative before making any
final
conclusions.
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