Sixty years ago, polio was infecting tens of thousands of children a year. In the past few years, despite setbacks, it has been brought near eradication. Two different vaccines are responsible for the fight against polio. An inspirational story... if the two people who developed the vaccines hadn't spent their whole lives hating each other.
Salk and Sabin
Although all advancements in science are the result of hard work, high-level training, and intelligence, in the early 1950s the development of the polio vaccine looked as close to a "paint by numbers" problem as medical science was going to get. There were two different avenues open to creating a vaccine for polio. One, which had recently been proven to work with the influenza virus, involved a killed-virus vaccine. The other avenue, older but considered more perilous after a failed previous attempt at creating a vaccine, involved a weakened virus being made into a vaccine. It was just a matter of which vaccine the National Foundation for Infantile Paralysis (NFIP) would choose, and who they would choose to develop it.
In the end, they chose the relatively young and unknown Doctor Jonas Salk, who had worked on the killed-virus vaccine for influenza. This was something of an upset, but no one can say that Salk didn't come through. He found a way to grow the poliovirus in monkey kidneys, then kill it off with formaldehyde. When he injected the vaccine into monkeys, they no longer grew sick and paralyzed in reaction to exposure to a live virus. When he injected it into humans, including his own family as a sign of his confidence in the vaccine, they also resisted the deadly effects of polio. Salk was hailed by the country as a hero.
This did not sit well with Arthur Sabin. Sabin was also a polio researcher, and had his own ideas about how to go about creating a vaccine. He experimented with growing the viruses in different media, and finding different mutations of the virus. When, at last, he found a variation of the virus that could excite the proper immune response without seeming to put anyone in danger, he developed that into another vaccine — one that could be taken orally instead of injected. He didn't get nearly the same exposure Salk did. This did not please Sabin, and he let his displeasure be known.
The Furious Feud
It cannot be said that either researcher handled the feud with dignity and aplomb, but given how long it went on, it's understandable that they both had their less-than-pleasant moments. Salk maintained a good public face, but being a good public face was, according to many, part of the problem. While Salk appeared humble in public, many of his staff members complained that he claimed all the credit for their work, and minimized their contributions. Salk seemed to quietly make a lot of enemies. Although there was a Nobel Prize awarded for polio research, Salk didn't get it. He also never got elected to the National Academy of Sciences, while many of his colleagues on the polio project did.
Sabin is the most quotable person when it comes to the feud. He would do things like call Salk directly and make accusations. He would also write scathing critiques of Salk, which was fair enough, except he would send copies of them directly to Salk with personalized cover letters. The text on one such cover letter went as follows:
This is for your information — so that you'll know what I am saying behind your back. This incidentally is also the opinion of many others whose judgment you respect."
Both men claimed their vaccine was the safest. At the time, Sabin had good reason to believe his vaccine was safer, as Cutter Laboratories improperly prepared a batch of the Salk vaccines in 1955. The virus wasn't completely killed, and the children who were injected with it got sick. Eleven children died. Sabin was rightly outraged officials downplayed the incident, and refused to switch to Sabin's live, weakened virus vaccine.
That being said, Sabin's vaccine wasn't entirely safe, either. While weak viruses do no damage to the vast majority of people who are exposed to them, they can and have caused serious and even fatal cases of polio. Both vaccines had drawbacks, although neither was as bad as letting the virus continue to spread unchecked.
Who Eradicated Polio?
One of Albert Sabin's famous quotes is, "I developed the vaccine, not a vaccine." The weak virus vaccine was given to people in the form of a sugar cube, which was cheaper than an injection. Because the virus was living and could reproduce inside the body, the weak virus vaccine didn't require as high a dose of the virus as the killed-virus vaccine did. As it was cheaper to make and easier to administer, it played perhaps the greatest role in reducing polio worldwide.
Today it's Salk's vaccine that is considered the standard. The killed-virus vaccine is the safest option, as there is nothing the dead virus can do to the human body except make it more able to withstand polio. The last person to get a polio vaccine will probably be getting Salk's shot.
In the end, the world benefited from having two different options for a vaccine — one that could be administered under any conditions, and one that is more expensive, but is safer. It's a shame that the two people who led the effort to fight polio were even more interested in fighting each other.