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Dec. 9, 2005
Lessons for medicine
Moral of Sabin and Salk: don't get complacent.
MONIKA ULLMANN
Fifty years ago, this lecture would have been packed," observed
Dr. Ned Glick, who was virtually the lone attendant at an eye-opening
journey through the historic battle against polio given by Dr. Mel
Krajden on Nov. 21.
Krajden, director of B.C. Hepatitis Services and associate director
of laboratory services at the B.C. Centre for Disease Control, gave
his presentation as part of an ongoing series examining the role
that Jewish culture played in the lives of famous historical figures.
His talk, Jonas Salk and Albert Sabin: Jewish Scientists and the
Race to Conquer Polio, not only explained the competing methods
and vaccines developed by these two giants of medicine; it also
threw a bright light on the politics and unscientific rivalries
that often beset medical breakthroughs. And it illuminated the current
hysteria over the outbreak of a low pathogenic virus in wild bird
populations in the Fraser Valley.
"It's only because we can actually isolate the virus under
the microscope that we're reacting the way we are," said Krajden.
"The birds aren't sick; they're carriers of a virus, and it
may or may not mutate."
As far as polio is concerned, the good news is that, by 1999, the
disease was eradicated from most of the globe. Krajden said there
are still some polio cases in India and Nigeria, partly the result
of fear-mongering. Women in India believe that the oral vaccine
will make them sterile, and Dr. Ibrahim Datti Ahmed, president of
Nigeria's supreme court for sharia law, accuses the Americans of
lacing polio vaccines with an anti-fertility agent or HIV. There
are no polio vaccines in Nigeria.
Krajden suggested that fear and ignorance are preventing the last
cases of the disease from disappearing forever. It has been a long
fight, which began with what Krajden called "a middle-class
plague," with 21,000 cases of paralytic polio reported in the
United States in 1952. The first outbreaks on this continent were
in 1848 in the United States and in 1910 in Canada.
Franklin D. Roosevelt, who suffered from the disease, established
the National Foundation for Infantile Paralysis and the March of
Dimes in 1938.
The two men who were to conquer polio were bitter rivals, said Krajden.
Both came from overachieving immigrant families and worked incessantly
to achieve their goals. Salk was the younger of the two, born in
1914 in New York City – the son of parents who worked in the
garment industry. A superb student, he came to the attention of
Thomas Francis, chair of biochemistry at New York University, who
became his friend and mentor.
Funded by the March of Dimes, he started to work on the polio virus
in 1948. He finally tested a pilot vaccine in 1952, which led the
way for massive field trials that began in April 1954. The injected
vaccine used the inactive polio virus, IPV. It was tested on children
from grades 1 to 5, with 441,131 getting the IPV and 201,229 receiving
a placebo.
By April 1955, success was declared by newspapers all over North
America. "Polio is conquered," shouted the headlines.
Almost immediately, it became known that some of the vaccines had
not been properly inactivated. The result was that many children
actually got polio from the vaccine. "In those days, nobody
bothered with getting permission," observed Glick.
The more easily administered oral vaccine developed by Salk's arch-rival,
Dr. Albert Sabin, overtook the one he had developed. Sabin was born
in Bialystock, Russia, but his parents escaped persecution and fled
to Paterson, N.J., in 1921, when Sabin was 15 years old. He too
attracted a sponsor, a dentist who partly financed his education.
He began a quest for a weakened strain of the vaccine and in 1956
he had an oral polio vaccine (OPV) ready.
Sabin conducted field trials in the Soviet Union from 1957-'59 and
started testing it in the United States in April 1960. It was easy
to use, more potent and longer lasting than the vaccine developed
by Salk – it gave lifelong immunity. The only drawback was
that it sometimes caused polio in children with weakened immune
systems. Still, Sabin's vaccine is credited with the almost complete
elimination of indigenous polio by 1970.
However, the OPV risk/benefit relationship has been reversed. According
to Krajden, there are now eight to 10 cases of paralytic polio per
year from VAPP, the vaccine used for paralytic polio in the States
This has resulted in the development of more sophisticated and safer
vaccines and, after some lawsuits, the discontinuation of the OPV
vaccine.
What is the lesson for today? "We cannot afford," said
Krajden, "to be complacent or listen to crazy conspiracy-mongers."
Monika Ullmann is a freelance writer and editor living
in Vancouver. She can be reached at [email protected].
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