Infectious Diseases: Rubella Vaccines

The 1963-65 U.S. epidemic of rubella, or German measles, was a national disaster. Rubella virus is as deadly as thalidomide for the unborn, and the epidemic left an estimated 30,000 babies marred for life by cataracts, deafness, heart malformations or mental retardation. Ever since, virologists have been racing against time, trying to perfect and test an effective rubella vaccine that can be marketed soon enough to avert the next predictable epidemic, expected in early 1970. Last week it appeared certain that the U.S. would have at least three different vaccines in time.

Besides the inevitable competing claims of the vaccine producers, there may be controversy as to which type is safest and most effective. The front runner so far is a vaccine named HPV-77 by the virologists who developed it in the Federal Government’s Division of Biologies Standards. This has already been tested on more than 20,000 persons and satisfies the three main requirements: 1) although it causes a mild rash in a few vaccinated children, it has no serious side effects; 2) it produces good antibody levels, and therefore immunity, in more than 90% of those vaccinated; 3) the weakened virus in the vaccine does not spread to people who come into contact with those who receive it. HPV-77 is also the only vaccine so far put to the test of a major natural epidemic, which erupted on Taiwan last winter. It protected 93% or more of Taiwanese grade-school boys.

Nose Droos. Even so, Dr. Stanley A. Plotkin of Philadelphia’s Wistar Institute noted at a Manhattan conference last week that while the virus in HPV77 is attenuated, it is still alive. This, he said, would be the first live-virus vaccine against any disease ever licensed to be given by injection. (The Sabin live-virus polio vaccine is taken by mouth.) Plotkin also noted that some lines of HPV-77 are grown in cultures of monkey-kidney cells, which may be contaminated by other, and dangerous, viruses. Not surprisingly, Wistar has its own vaccine, also live-virus but grown in cultures of human cells and therefore free of animal viruses. This, said Plotkin, has the further advantage that it can be given in the form of nose drops, whereas other vaccines must be injected under the skin.

A third live vaccine, an injectable one produced in Belgium and grown in rabbit-kidney cells, is being extensively tested by Smith Kline & French Laboratories. Because of its head start in Europe, this may be the world’s first licensed rubella vaccine. Additional U.S. testing will probably take a year.

Although the purpose of vaccination against German, or “three-day,” measles is to protect pregnant women for the sake of the unborn, the plan is not to vaccinate women.* Instead, public health officials hope to stamp out rubella by vaccinating children; thus, as they put it, “drying up the reservoir” of susceptible subjects who spread the infection. Some time in their lives, most adults have had a touch of rubella with no ill effects, and are now immune.

*The last epidemic created a widespread demand for legalization of therapeutic abortion in cases where a woman has had rubella in the first three months of pregnancy.