Monday, October 26, 2009

Epidemic! The Battle Against Polio

Just finished reading "Epidemic! The Battle Against Polio" by Stephanie True Peters last night.

Some interesting facts from the book:

There are three kinds of polio virus, Type I is called Brunhilde, after a chimpanzee. Type II is called Lansing, after a town in Michigan. Lansing was the hometown of a man who died of polio. Type III is called Leon, after an 11 yro old boy from LA. The vaccine contains all three strains as antibodies that fight against one strain do not protect against the other two strains.

Wild Polio - Polio caught from the environment (not from another person) (my note/question/thought: Might it always be from another person and maybe appears to come from the environment, but we just don't know this yet?)

1979 was the last case of wild polio in the United States (that was recorded).
1991 was the last case of wild polio in the Western Hemisphere (that was recorded...and as of the writing of this book which was 2005).

1952 was the latest big polio epidemic in the US.

Dr. Jonas Salk, developed the first effective polio vaccine in the form of a killed virus given via shot.

Salk did two secret experiments on humans to test out his killed poliovirus vaccine - the first (spring 1952) was done on kids just outside of Pittsburgh who lived in the D.T. Watson Home for Crippled Children. Only the subjects (who had polio before) and the staff knew. The experiment was a total success as the blood samples from the kids had increased antibodies after getting the polio shot. The second trial (date? who were the subjects?) was conducted on humans who never had polio before. Luckily it too was a success as the people's antibody levels rose and they did not contract the virus.

In 1953, Salk got support from the research community and conducted his trials using a few hundred subjects at a time. Each trial produced positive outcomes.

In 1954, the National Federation of Infantile Paralysis (NFIP) sponsored a nationwide vaccination program using Salk's vaccine. It cost about 9 million dollars (back then!!) for 27 million doses of the vaccine. Of about two million children, 1/2 were given the vaccine and 1/2 were given a placebo. The trials were a success. In 1955, Salk received a license to market his vaccine. Doctors around the world could now vaccinate people.

Unfortunately, in April 1955, Cutter Laboratories in California made a batch of vaccine that mistakenly contained some lives viruses. 204 children contracted polio. Of those 204, 153 became paralyzed and 11 died. Note that some kids got it not via the shot, but by contracting it through those who received the shot. This made other manufacturers more careful, but it did not halt the vaccination campaign for polio.

The NFIP is now called the March of Dimes. This organization was created by FDR who contracted polio as an adult before becoming President and during a stay in Campobello Island in Canada in 1921. And today ..some doctors and scientists think that FDR actually had Gulliane-Barre syndrome, not polio. Other doctors and scientists still think he had polio.

- Intermission -
My own thoughts.....
.....With the use of Salk's (shot) vaccine, there is a chance that some virus might still be alive as per the incidence at Cuter Labs in April 1955. Guess those taking the shot choose to take the risk that the lab that made their vaccine batch used utmost care and sanitation. Page 56 of "Epidemic! The Battle Against Polio" book says, "Yet not everybody agreed that the Salk vaccine was the best. Some pointed to the Cutter Laboratories incident as proof that using a killed strain of the virus could be dangerous, since, they argued, ther was no way of knowing whether all the viruses had been killed. One person who raised his voice in loud opposition to Salk was Dr. Albert Sabin." And yet if a person gets the Sabin vaccine (live oral virus), it offers better protection, but more chance (maybe? depends on how careful those labs are making the killed virus I suppose) that one will contract the virus from the vaccine. Hmmm. Tough call. I got the live vaccine as a child. I remember being grateful it was an oral vaccine as I feared shots. I am so glad I did not contract the virus. What would people do if the virus resurfaced? If an epidemic broke out and I was not vaccinated, I would seriously consider either vaccine - both have their pros and cons as mentioned above. As of now, if I were unvaccinated for polio and stayed in the USA, I'd feel comfortable. However, if I were to travel to another country, I would research whether it would be wise to get the vaccine. Prudent decisions or not? Only time will tell. And each of these decisions are so very personal and should be decided by each individual - or they should be up to each individual!!.

- Back to the story....introducing Dr. Albert Sabin
and his live oral polio vaccine -

Dr. Albert Sabin believed live viruses to be better than killed virus for a polio vaccine. He found evidence that poliovirus entered the body through the mouth and created a live atttenuated oral vaccine. (attenuated virus means a weakened virus) He did his testing and further research overseas and finally got the attention of the World Health Organization(WHO). In 1957, WHO authorized the mass vaccination of children living in areas with polio epidemics, especiall Russia. By 1959, 4.5 millions of Russians had received the oral vaccine and polio had declined. This success got the attention of the United States and in 1960 Sabin's live polio vaccine was licensed in the USA. By 1965, oral vaccine was used most often all over the world. Polio in the USA decreased from 37,000 cases during 1951-1955 to approximately 600 cases in the early 1960's.

Oral poliovirus vaccine (OPV) is responsible for causing vaccine-associated paralytic polio in one out of every 2.2 to 3.5 million people. Therefore, in 1999, the Center for Disease Control (CDC) recommended the Salk vaccine (shot of killed virus) instead of the Sabin OPV. However, in countries where wild polio still causes the disease (afghanistan, Pakistan, India, etc), OPV is still used and even preferred as OPV creates antibodies in the blood and blocks the virus from replicating in the intestinal tract. Because Salk's vaccine is injected, it does not enter the digestive tract and can allow the virus to replicate in the intestines.

It was once thought that polio was not even a virus. In 1908, Dr. Karl J. Landsteiner and Erwin Popper said that it was a virus. Yet in 1916, people still had crazy ideas (maybe due to the epidemic....they were fearful and panic stricken) - some thought animals passed it, others thought mosquitos passed it. Some even thought tarantulas injected the virus into bananas! It took time to discover that poliovirus enters through the mouth and replicates in the gut and is transferred via fecal matter. Usually a person caught the virus by drinking or swimming in contaminated water. (My note: But since it is a virus, I'd assume that any transmission of the virus to another person's mouth could obviously transmit it.)

Sister Kenny ("sister" means nurse in Austrailia), an Australian, invented a way to help polio victims. Because her ways were different than conventional treatments, doctors were not interested in her therapy. She wrote once that "the extraordinary attitude of the medical world in its readiness to condemn anything that smacked of reform or that ran contrary to approved methods of practice." She once wondered "how many promising discoveries have been consigned to oblivion without being given an opportunity to prove their worth." She later did come to the US, had great success here and was even invited to lunch with FDR! (I must read more about her!)

Since 1988, the Global Polio Eradication Initiative, a joint venture of the WHO, CDC, UNICEF and Rotary International has been active in eradicating the disease.

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