The Salk Vaccine Fiasco
BY
DR. ALFRED BYRNE WHEN the results of the Salk vaccine trial were assessed
statistically, the vaccine was pronounced to be effective, potent, and
'incredibly' safe. It has since proved so in Canada, where a million children
have been vaccinated against polio, none of them developing para- lysis
attributable to the vaccine. Yet the same type of vaccine prepared on a
commercial scale in America has apparently proved incredibly dangerous; so
dangerous that the British Government last week cancelled the proposed clinical
trials of the Salk vaccine. What went wrong? What, or who, is to blame for the
fact that so many American children injected with the Salk vaccine, and others
in contact with them, after- wards developed paralytic polio, which in some
cases was fatal?
It
now seems clear that some of these stricken children were given injections
containing the living virus. Dr. Salk based his whole case on the assumption
that the virus can be inacti- vated by formaldehyde, and that there is a clear
interval between the time the virus is inactivated and the time it loses its
power to excite the required antibodies—a time in which the virus is safe, but
still potent for vaccination purposes. In this very critical assumption, Salk
turns out to have been wrong.
Last
month (June) the US health authorities issued a tech- nical report on the Salk
vaccine. A British scientist closely concerned with polio policy in this
country, with whom it was discussed, described it as 'a terrifying document.'
The epithet may be unscientific but it is horribly apt. The Surgeon General of
the Health Service, Dr. Leonard Scheele, from whose department the report
emerges, has attempted to reassure the American public. But the report makes it
clear that the vaccine, prepared according to Dr. Salk's original
specifications, can be extremely dangerous. According to the report, Dr. Salk
was of the opinion that the process of inactiva- tion goes smoothly and
regularly from beginning to end. The experience of manufacturers, however,
suggests that the inactivation slows up as it goes along, so that it takes far
longer than was first thought to render the final tiny particles of the virus
inactive. In fact, there may be still a minute number of these active particles
still present at the end of the, whole procedure. Several of the six manufacturers
licensed to make the Salk vaccine have had the daunting experience of finding
active virus—in one instance, in four out of six batches tested—in the vaccine,
when it should have been safe and ready for use.
Much
of the American work which went towards developing this and other anti-polio
vaccines was financed by the National Fund for Infantile Paralysis, whose
president, Mr. Basil O'Connor, was a business partner of the late President
Roosevelt. In attempting to apportion the blame for the con- fusion in the
present mass immunisation which, after starting, Stopped, restarted, and is now
at a standstill again, the Fund must not be forgotten. Some months before the
publication of the Francis report on last year's field trial, to which even
Salk had not access, the NFIP placed an order for $9 million of the vaccine.
That extravagance could be interpreted either as a benevolent gesture towards
the manufacturing houses, or else it sprang from a burning but unscientific
desire to get on with the vaccinating and be damned, because at that time there
had still been no convincing proof that vaccines of the Salk type were
clinically effective against poliomyelitis in human beings.
The
Fund, which sponsored the field trials and paid for the assessment of the result,
was also, alas, behind the disgustingly vulgar and misleading publicity that
accompanied the announcement of the results at Ann Arbour, last April. There is
a rule of conduct observed on all levels of journalism that one must not
publish news which might raise false hopes or foster a false sense of security
in matters pertaining to health. Such, of course, was not the intention, but
that was the effect of the NFIP's exuberance in turning the announcement of the
Francis report, a formal and highly technical scientific paper. into 'the
greatest show on earth.' Even the selection of the day for the publication of
the paper—the tenth anniversary of the death of Roosevelt, who had been a polio
sufferer— smacked more of the circus than of the campus.
But
when joybells rang, sirens sounded and the glad news that the Vaccine was a
success was flashed across the tele- vision screens of the continent, lbw could
the press be expected to present the story in its proper perspective? The
newspapers seized happily on a sentence from the Francis teport that the
vaccine had proved successful in warding off Paralytic polio in from 60 per
cent. to 90 per cent. of cases. Carried away by the occasion, Dr. Dwight
Murray, chairman of the American Association's board of trustees who, pre-
sumably, had not had time to read the report, declared the Salk vaccine 'one of
the greatest events in the history of medicine.' No less moved. Dr. Salk said
he was 'sure' that bring vaccine was potentially 100 per cent. effective and
could bring complete triumph over polio. A more cold-blooded appraisal of the
results of last year's experiment would have shown that there is still no
information if the vaccine is effective in infants, how long the immunity may
last and what will happen if the children require to be reinjected with a
vaccine whose virus has been grown from potentially danger- ous monkey kidney.
There
was, however, no time for cold blood on April 12. The infectious enthusiasm of
the NFIP had already spread to the. Department of Health, Education and
Welfare, the long- expected resignation of whose secretary, Mrs. Oveta Culp
Ho4y, took place last week (July 13) 'for personal reasons of high order.'
Given a preview of the report, Mrs. Hobby's department was ready to issue
licences on the big day to approved firms to manufacture the vaccine. When,
later, Mrs. Hobby was sharply criticised for the way her department had'
handled the vaccination programme, she made the astonishing statement that she
had not anticipated the great public demand for the vaccine. It is hard to see
how anyone could underestimate the effect that the NFIP's rather shameful
publicity stunt would have had on the parents of America, where the problem of
polio is a larger and far more personal proble— than it is here.
At
mak, the health authorities checked batches of the manu- facturers' vaccines to
ensure that they were safely free froth active virus.
Later,
in response to public demand, the regulations were relaxed and the health
authorities released a large proportion of the vaecine used this year after
scrutinising the makers' records of their methods . of manufacture and testing.
Other batches were tested by tissue culture and on monkeys. Now, however, it is
known that the monkey test for live virus is so crude as to constitute a source
of danger since it will not always, by any means, differentiate between the
presence of no live virus and live virus present in small amounts. No wonder
some of the more reputable American virologists have (last inonth) voted to
stop using the Salk virus for this year's programme.
It
was indeed a bleSsing that the newspaper strike saved the health authorities of
this country from the obvious charge on the part of the unthinking of being too
cautious.
The
remarkable fact is that so few cases of paralysis fol- lowed the use of Salk's
vaccine. The number of casualties might hate been multiplied ten- or a
hundred-fold. If the British health authorities had been as impulsive\ as their
American counterparts this recent American tragedy could have been reproduced
here. Thank God for British phlegm !
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