Many people associate the name Jonas Salk with the eradication of polio in much of the Western world. It’s ironic that people may fail to remember the other important name, Albert Sabin, that assisted in this quest, after Salk’s discoveries. The oral polio vaccine or Sabin vaccine was used almost exclusively in some places after it was developed in the 1950s, instead of Salk’s formulation. Though now organizations like the Centers for Disease Control are actually in favor of the Salk vaccine’s almost exclusive use, for many years doctors used the Sabin vaccine exclusively or combinations of Salk/Sabin immunizations.
One of the appeals of the Sabin vaccine was its oral administration, and it is thought to confer greater protection for a lifetime against the polio virus. Up until recently, doctors’ offices were stocked with small plastic containers containing several pink-colored drops that could be given to infants and older children on the appropriate vaccination schedule. The benefits of no needles could be extolled by those giving vaccinations to pained and resistant children, but also the ease of carrying the vaccination and giving it on a wide scale was praised.
The Sabin vaccine had some differences from Jonas Salk’s initial injection. First, it was made from what is called a live attenuated virus. This is a virus that has undergone some changes to make it less likely to cause contagion. It still confers immunity, but is usually unlikely to cause disease.
In practice this theory has not always worked well, and there are people who should never use the oral polio virus, or perhaps be caretakers for those who receive it. Any type of immunosuppressed condition may make it more likely that the Sabin vaccine could cause polio, and it is possible for a child having received the vaccine to pass it onto an immunosuppressed parent who is performing basic care like diaper changing. It is in part based on this heightened risk, and the reduced risk of catching wild virus polio that the oral polio virus is no longer recommended.
Given greater awareness of potential for polio contagion from the Sabin vaccine, doctors evolved a number of methods to reduce this chance. One was careful screening of receivers or their caretakers for diseases that might make them more prone to infection. In the 1990s, it was common for doctors to recommend using both the oral and inactivated/injection form. Children might start with injections of the inactivated polio vaccination and then at an older age would have at least one dose of oral polio vaccine.
In the 2000s, assessment of risk of catching live polio is rated lower and most doctors and health organizations no longer recommend administration of the Sabin vaccine. Yet it must be credited with doing much to eliminate polio in many countries. It has essentially made it possible to administer only the inactivated virus as conceived by Salk, since risk of wild polio contagion in countries with strong vaccination plans is extremely low.