Vaccination: A Grant of Immunity
Robin Rowland, CBC News Online | March 3, 2003
Throughout the early history of mankind great plagues killed
millions of people. Often, healers noticed that, with some
diseases, once a person had become ill they didn't become
reinfected. One of the first written records of acquired
immunity came from the Greek author Thucydides who
noted during the great plague of Athens, in the fifth century
BC, that the people who survived did not get the disease
again.
It was in China in the 10th century that an early form of vaccination called
variolation was first used to combat smallpox. Healers would take samples of the
lesions caused by smallpox, grind them into powder, and put some under the skin or
inhale them through the nose.
Variolation reached Europe in the 18th century. In 1721, a royal physician in London
experimented on prisoners and found it was a somewhat successful way of
preventing smallpox. Those who were inoculated usually had a mild form of the
illness, though there were deaths.
The idea of vaccination began with an English doctor named Edward Jenner, who
began practising in Berkeley, Gloucestershire, in 1773. Jenner noted that local
farmers believed anyone who had become infected with cowpox wouldn't get the
more deadly smallpox. In 1796, Jenner began an experiment that today would be
considered unethical. He inoculated an eight-year-old boy with cowpox and later
exposed him to smallpox. The boy did not get the disease.
Jenner published his first treatise in 1798 and hospitals in London began vaccination
soon after. In 1802, the British Parliament awarded Jenner £10,000 to continue his
research. Around the world, individuals and countries began to adopt vaccination. In
1805, both Mexico and Guatemala were vaccinating their population. In 1807,
Bavaria made vaccination compulsory.
From the beginning, some people refused to believe vaccination worked, and refused
to be vaccinated. When the British House of Commons passed an act in 1853 to
make it compulsory, an anti-vaccination movement grew up. In 1870, a man named
George Gibbs complained of "medical spies" forcing themselves into people's homes.
In 1898, Britain changed the act to allow people to opt out of vaccination programs.
In France, Louis Pasteur was researching infectious diseases by growing bacterial
cultures and found that old, weakened bacteria didn't cause diseases in animals. In
1885, he first used weakened rabies bacteria to stave off an infection. Five years
later, two researchers found that animals inoculated with small amounts of toxin
could become immune and this led to vaccinations for diphtheria and tetanus.
Advances since World War II
It was only after the Second World War, with the new technology and
communications and the establishment of the World Health Organization, that there
were widespread efforts to promote vaccination.
There were also new advances, such as the discovery of the polio vaccine in 1954,
which used a killed version of the virus. The injectable vaccine was replaced with an
oral version in 1962, and according to the WHO, the vaccine "dramatically" reduced
the number of polio cases.
IN 1980, the WHO's campaign to eradicate smallpox was considered successful.
The World Health Organization estimates that vaccination saves millions of lives each
year-and it says that the lack of vaccination kills two million children a year, most of
them in the developing world. The WHO also estimates that 90,000 children fall
victim to polio each year, a disease that has been prevented by immunization in the
west since the 1950s.
The WHO had announced the aim of eliminating polio by the year 2000. By 1995, the
WHO estimated that 78 per cent of the world's children had received three doses of
polio vaccine. The same year, 146 countries reported no cases of polio. Although the
WHO did not make its goal, it says in most of the remaining areas, polio can be
described as "low-incidence."
Although the WHO set a target of immunizing 90 per cent of the world's children
against measles, the campaign has been less successful than the one against polio.
The organization is now trying for a new target, cutting measles deaths by 50 per
cent by 2005.
The problem, the WHO says, is that thousands of measles cases continue to occur in
the developing world, especially in Africa. The highest transmission rates occur in
areas of dense population, where people live in crowded cities.
Anti-vaccination fears
The British Medical Journal says, "immunization against infectious disease has
probably saved more lives than any other public health intervention apart form the
provision of clean water." It notes that improved living conditions are also
contributing to better lives.
The BMJ notes that without vaccination, smallpox would not have been eliminated
from the world-or at least smallpox is its wild state.
At the same time, there is a small but growing anti-vaccination movement.
What the BMJ calls "a vocal minority of parents" in Britain are opposing vaccination,
believing that the vaccination itself could be more dangerous than the disease. But,
as the journal points out, diseases such as measles, diphtheria and polio are still
common among unimmunized populations and could spread easily among a family or
community that forgoes immunization.
Dr. Ron Gold, a former head of infectious diseases at the Hospital for Sick Children in
Toronto, told The Current that a lot of parents fear the things that could happen with
vaccinations, and that fear makes them lose sight of the problems vaccinations
prevent. He adds that vaccinations can get the blame for childhood diseases that
parents can't otherwise explain.
Health Canada has noted on its Web site that the anti-vaccination movement causes
more problems than it solves.

In Ireland in 2000, measles cases rose to 1,200 from 148, after immunization
rates fell to 76 per cent. A number of children died.

In 1994, there were 5,000 cases of rubella in Russia after organized
immunization was suspended.

In the United Kingdom, after a major drop in pertussis (whooping cough)
immunization in 1974, there was an epidemic of whooping cough in 1978,
with more than 100,000 cases and 38 deaths.
Gold says in the U.K., publicity over unproven dangers from the measles-mumpsrubella (MMR) vaccine led to a drop in immunization rates; in Russia the problem
was fear of HIV from shared needles.
One of the biggest controversies is over thimerosal, an organic mercury compound
preservative added to some vaccines. Parents have claimed that thimerosal is linked
to autism in their children. In the United States, the Food and Drug Administration
investigated thimerosal and concluded that the risk to a baby receiving vaccines was
low and theoretical, that thimerosal was dangerous only in high doses. However, the
agency recommended that thimerosal be taken out of childhood vaccines.
Gold says, thimerosal was removed from most vaccines because it was no longer
needed, and there was a demand for a purer vaccine.
In Canada, there are small amounts of thimerosal in both the diphtheria -poliotetanus (DPT) and the hepatitis B shot. Gold says the preservative is metabolized as
ethyl mercury, which is less dangerous than methyl mercury, and is expelled from
the body.
Gold says the thimerosal controversy is not the first. He notes that parents once
claimed that the MMR shot was causing autism, until a number of studies showed no
connection,
He notes that there has been an increase in the rates of autism but that may be
because of an increased awareness of the disease.
Gold also says the increases in autism came long after thimerosal was introduced in
the 1930s, so it is hard to see what the link may be. Children usually receive their
first vaccinations around their first birthday and autism usually surfaces around 18
months.
Health Canada's Dr. Paul Varughese says the department has created a database to
track the side effects of vaccination, a database that is updated regularly from
doctors' reports.
Mary James, of Manitoba's Association for Vaccine Damaged Children says Canadians
should be concerned about the so-called "five-in-one shot"-the practice of putting
five vaccines in one shot. James she says that could overwhelm the "immature
neurological and immunological system."
Gold says there is no evidence that vaccines can over-stimulate an immune system.
He points out the natural environment challenges a child's immune system every
day. Challenges come from protein in food, bacteria on the skin and in the intestinal
tract and from viruses.
Bioterrorism
The spectre of terrorism is adding urgency to the debate over vaccination. Countries
around the world are stockpiling smallpox vaccine in case of a terror attack.
In the United States, President George W. Bush and the Department of Health and
Human Services ordered a mass vaccination program for front-line health care
workers.
Many, however, refused to take part because of fear of side effects. By the end of
February, the first month of the program 7,354 civilian health care and public health
care workers had been vaccinated, out of an estimated 450,000. The plan was that
those health workers would then vaccinate up to 10 million people in a threatened
area. The Centers for Disease Control reported that only two people had suffered
minor side effects. Studies show that for every one million people vaccinated, one or
two people could die and 52 become seriously ill.