THE POLIO SUGAR CUBE

Is It Safe?

In 1960 a medical debate raged over the polio vaccine. In 1954 Dr. Jonas Salk had produced a killed-virus vaccine that was administered by injection and was 90 percent effective. The vaccine seemed relatively safe and cheap. Then in 1955 Dr. Albert B. Sabin of the University of Cincinnati produced a live-virus vaccine that was placed on a sugar cube and eaten, rather than injected. Researchers, physicians, and patients were wary. Researchers suspected that the attenuated, or weakened, virus might gain the strength to cause polio once it was introduced into the human body. Physicians felt the Salk vaccine had been proven, and it was not worth the risk to switch to an oral vaccine simply for the sake of convenience. Patients were suspicious of a process of preventing polio by eating the live polio virus.

A Cautious Success

The live-virus vaccine was tested as an oral medication on children between six-months and one-year old in Houston, Texas, and on children under five in New Haven, Connecticut. In Cleveland, Ohio, newborn babies were given an eyedropper full of vaccine without the sugar cube. Large-scale testing was done outside the United States. In the Soviet Union the Sabin vaccine was given to twelve million people. By the middle of 1960 U.S. Surgeon General Le Roy Burney gave results of two years of testing on one hundred mil-lion people around the world. The Sabin vaccine was 95 percent effective and was cheaper than the Salk. It also provided "herd immunity," the ability of the vaccine to pass along its protective qualities by infection.

Sabin's Vaccine in the United States

Still, the vaccine was introduced cautiously. By August 1960, 800,000 Americans had taken the Sabin vaccine. A major study was conducted in Miami and its vicinity in Dade County, Florida. Statisticians predicted that during the term of the study twenty-seven cases of polio would occur in the county. Only eight were actually seen, however, and none of them were of the same virus type as the one used in the vaccine. The oral polio vaccine was approved for general use in August 1961 and all but replaced the killed-virus vaccine.

Three Types

There are three types of polio virus. The Salk vaccine was effective against all three types but was weak against Type III. The oral vaccine originally approved was effective against only one type (Type I), but the Type II oral vaccine was ready for approval soon after the Type I. The Type III oral vaccine experienced a delay in U.S. distribution, though; when it was injected directly into monkeys' brains, some nerve damage resulted. Although millions of people around the world had already taken the Type III oral vaccine without experiencing problems, the Public Health Service withheld approval until the vaccine met their strict testing requirements.