One of the tests was whether you could lift your head off the
bed, he said. I remember not being able to do that, and wondering
what that meant. It meant polio, one of the most feared diseases of all
time. The viral illness paralyzed tens of thousands of children in the United
States and half a million worldwide each year. Wilson was among the last
Americans stricken. On April 12, 1955, scientists announced they had a
successful vaccine. They made it without even being able to see the virus --
microscopes weren't powerful enough back then. They did it at great personal
risk, without modern protective gear or fancy lab equipment. It wasn't the first
vaccine -- ones for smallpox, diphtheria and the flu preceded it. But it became
another shot heard 'round the world, revolutionizing how people
viewed science and launching a new war on germs.
Scientists headed to labs with fresh enthusiasm, convinced they could brew
similar magic potions against other scourges of mankind. It seemed to say it was
only a matter of time until we beat infectious diseases, said Wilson, now
a historian at Muhlenberg College in Allentown, Pennsylvania, and author of a
new book about polio. Today, we have more vaccines than we did 50 years ago, and
more tools and knowledge to make them. But we also have more and different kinds
of germs. Hubris has turned into humility in the face of failure to develop
vaccines for many of them. In fact, many of the world's top killers -- AIDS,
malaria, tuberculosis -- got that way because there aren't effective vaccines.
Infectious diseases are still the third leading cause of death in the United
States, and they kill more than 1 in 4 people worldwide. Existing vaccines
aren't panaceas either. Recent years have seen debate over resuming smallpox
shots, the safety and effectiveness of other vaccines, and whether the widely
used vaccine preservative thimerosal caused health problems.
The most common vaccine of all -- the annual flu shot -- is under intense
scrutiny. Issues include the antiquated way it is made, a fragile supply system,
worries about the threat of a pandemic, and research suggesting it might not
help as much as had been believed. Vaccines also are about money as much as
medicine, sharply dividing the haves and have-nots. The world's richest man,
Microsoft founder Bill Gates, has donated a staggering 1.5 billion for
immunizations in poor countries, where more than 2 million children die each
year of diseases largely vanquished from the United States. Even the polio
vaccine is only a partial success story. Officials have been unable to rid the
world of the Great Crippler as they once did smallpox, and many
doubt they ever will.
Despite these problems, vaccines clearly have changed the world and saved
millions of lives. The challenge now isn't just developing new ones, but also
getting parents to accept existing ones, said Dr. Neal Halsey, director of the
Institute for Vaccine Safety in Baltimore. Here at Johns Hopkins
Hospital, Halsey said, we have a child who is basically on a
ventilator and has severe pertussis. The child is lucky to have lived, almost
died. We have another child with meningitis that could possibly have been
prevented by a vaccine. I have seen children with all of the diseases that we
currently protect against with vaccines. Once you have seen children die from
those diseases, you want to do what you can to help prevent other children from
dying, and vaccines are our best tool to do that.
For many years, it seemed fairly simple. Scientists would isolate a germ,
kill or weaken it so it was no longer harmful, and give it to people so their
immune systems would go on alert and be able to recognize and attack the real
bug if they ever caught it. One by one, diseases began to fall. Measles, mumps,
rubella. Hepatitis, meningitis, chickenpox. Even cancer turned out to be
vulnerable: the hepatitis B vaccine wound up preventing liver cancer, too.
Modern genetics gave the field a boost, cutting the time it takes to analyze a
germ and providing a way to make vaccines from gene segments. Some of this
research is really wild: Scientists are growing what could be tomorrow's flu
shots in insect cells instead of chicken eggs, and an Arizona biologist is
developing vaccine-laced potato cubes that can be freeze-dried, shipped around
the world, reconstituted and given to children to eat.
Each new germ poses new challenges
But after decades of successes, reality set in. Each new germ posed unique
challenges. A promising vaccine against rotavirus, a killer diarrheal disease,
was withdrawn after it was linked to a rare but serious bowel problem. A Lyme disease vaccine lasted on the market only four years. Even though no
science supported allegations that it was unsafe, its manufacturer didn't want
to defend the product in the face of limited sales.
There have been shortages of some childhood immunizations, and of companies
to make them. Timing is a problem. Scientists rush to develop a vaccine when a
scary new disease appears, often to see the germ diminish in later years and be
eclipsed by newer threats. Today, the big worry is bird flu, said Dr. Gary Nabel,
director of the Vaccine Research Center at the National Institutes of Health.
A year from now it could be something else. A couple years ago it was West
Nile virus, then SARS, he said. What it points out is the need to
have a more concerted and longterm vision for public health with respect to
infectious diseases, and to view vaccines as just one tool for controlling
them, along with quarantine, antibiotics and antiviral drugs, Nabel said. The
biggest disappointment has been the long quest for an AIDS vaccine. Nothing has
proved effective at preventing HIV infection, or preventing infection from
developing into AIDS.
Nabel refuses to give up. We can't afford to say, 'Oh, it's too hard,'
and not work on it. We need to bring all we can bear in terms of the science to
try to attack it rationally, he said. Several problems have been
insurmountable. The virus attacks the immune system -- the very thing vaccines
depend on to work. HIV also constantly mutates, so giving a vaccine strain won't
protect against other forms. In this respect, HIV is like flu viruses, which
change so much that new vaccines continuously must be made. We were fairly
lucky working on polio because we had a very genetically stable virus and we had
a disease that induced longterm, permanent immunity itself. We just had to
duplicate what mother nature did naturally, said Dr. Walter Orenstein, an
Emory University vaccine expert who for many years led the National Immunization
Program at the federal Centers for Disease Control and Prevention.
Polio itself is an unfinished victory. Seven years after Jonas Salk's vaccine
-- a shot that uses killed virus -- Albert Sabin made a vaccine using live but
weakened virus that could be given orally, an easier form for developing
Polio still unfinished victory
Polio was eradicated in the United States in 1979, and the World Health
Organization in 1988 launched a drive to do it globally. By 2001, polio had been
confined to just 10 countries. But setbacks occurred. The Caribbean had
outbreaks when the weakened vaccine virus mutated back into a form that caused
disease. Parts of Nigeria stopped using the vaccine because of rumors it caused
infertility. Polio resurged and now is in more than a dozen African countries
that once were polio-free. Dr. Donald D.A. Henderson, who helped
lead the smallpox eradication campaign and is now at the University of
Pittsburgh's Center for Biosecurity, thinks the polio campaign should be
abandoned and efforts focused on controlling outbreaks.
He said extraordinary work has been but added, The probability of
eradication is not high. Dr. Stephen Cochi, the CDC's National
Immunization Program director, has clashed with Henderson and has a different
view of Nigeria's misstep. I think the folly of that basically political
decision has been recognized, and the negative impact that it has had on African
children and the adjoining countries has resulted in a new resolve to
stamp out the disease, Cochi said.Rotary International, which has given 500
million and raised another 123 million for the cause, is in this till the
very end, said spokeswoman Vivian Fiore.
And it still believes the end is in sight.
(Source: CNN.com, April 11, 2005)