Medicine: Man v. Viruses

Of all mankind’s enemies, the tiniest and most elusive may also be the toughest : viruses. Despite recent breakthroughs, such as development of vaccines against polio, viruses still cause an immense amount of disease. There are no cures or even effective treatments for illnesses brought on by the smaller, typical viruses. These facts were emphasized last week as the American Public Health Association convened in Atlantic City, with a generous sprinkling of foreign experts to sound the keynote, “Public Health Is One World.”

The more man learns about viruses, said the University of Minnesota’s Epidemiologist Leonard M. Schuman, the more he has to learn about controlling them. And this circular motion has speeded up enormously. Up to 1947 only 60 viruses had been listed as causing disease in man, and a mere 20 of these singled out the human species as their prime prey. The rest, like the one that causes eastern equine encephalitis (TIME, Oct. 5), normally attack lower animals, infect man accidentally, said Dr. Schuman.

Pandora’s Box. Then the isolation of Coxsackie virus by New York’s Dr. Gilbert Dalldorf (TIME, Oct. 19) in 1947 opened a Pandora’s box of viruses. By now, 76 new types of viruses that prey on man have been described—more than all the viruses of any kind recognized before 1947.

To the ailing human and his physician, a major difficulty is that viruses cannot be identified by the disease they cause—many different ones may produce seemingly identical symptoms. And a single virus may touch off, in different people, symptoms ranging from a “cold,” a “sore throat,” or “fever” to paralytic polio. Even paralytic polio cannot be diagnosed as surely as was believed in what Dr. Schuman called “the happy, unenlightened first quarter of this century,” because several viruses simulate its signs. Even such time-honored children’s infections as measles, German measles and mumps may deceive the physician. So, said Dr. Schuman, diagnosis often cannot be positive without a battery of laboratory tests.

TP for KFD? Reports of progress and setbacks came from disease fighters on far-flung sectors of the virus front: <J India’s Dr. Chindaman Govind Pandit: in the forests of western Mysore, a virus kills monkeys and men with a hemorrhagic fever dubbed KFD (Kyasanur forest disease). Though the virus is akin to that of Russian spring-summer encephalitis, Soviet-made RSSE vaccine gives negligible protection against it. While India is trying to make a safe vaccine from KFD virus itself, Dr. Pandit hoped for help by a roundabout route. British researchers in Malaya have isolated (from rodents) a related virus known as TP-21. It protects mice not only against KFD but also RSSE and other diseases of the group. Dr. Pandit suggested that a vaccine made from a live but nonvirulent form of TP-21 (the hope that was also in Pandora’s box) might benefit millions in the whole of Europe and Asia. Cf The University of Michigan’s Dr. Gordon C. Brown: widespread Salk vaccination of childbearing women has led to unexpected complications in protecting their infants against polio. If the mother had no antibodies, her baby responded well to vaccination when only two to four months old. But now most young mothers have the antibodies and pass them on; they persist for about six months in the babies. And these babies get little benefit from early vaccination (the mother’s antibodies get in the way). Better wait until mother’s antibodies have died out before giving polio shots, suggested Dr. Brown. CJ Toronto’s Dr. Donald M. McLean: to the long list of exotically named viruses must be added Powassan, after a town (pop. 935) in northern Ontario. A Powassan boy of five died of encephalitis similar to the eastern equine variety, and the guilty virus proved to be of the same family. It can infect man without causing disease: 3% of the adults tested around North Bay had antibodies against Powassan but no history of a mystery illness. Chipmunks and squirrels are suspected of harboring the virus, but how it gets from animal to man is not known.

Reversion to Type? Word of the world’s most massive attack on disease, using live-virus vaccines as the weapons, came from Moscow’s Virologist Anatoli A. Smorodintsev. Dr. Smorodintsev told an avid audience that Soviet scientists give full credit to U.S. pioneering by Drs. John F. Enders. Jonas E. Salk. Hilary Koprowski and Herald R. Cox. But he noted that while the Salk killed-virus vaccine protects 70-80% of the vaccinated against paralytic polio, it has no effect on the persistence of polio virus in a community. So it cannot be expected to wipe out the disease.

With more boldness than U.S. medical authorities have shown, the Russians took up the vaccine made from live (but weakened) virus by Russian-born Dr. Albert Sabin, now at the University of Cincinnati (TIME, March 16), made it themselves. They have given it to almost 12 million children under 15, of whom an estimated 2,500,000 were susceptible to polio. The rest served as a check on the vaccine’s safety. Most urgent was the fear, still held in some U.S. and British circles, that while multiplying in vaccinated children’s digestive tracts and spreading to siblings or schoolmates and multiplying again, the virus might mutate and regain its power to cause paralysis. Not so, said Dr. Smorodintsev, emphatically: in elaborate tests of both vaccinated and contact children, there has been no sign of reversion to type.

The Soviets’ domestic aim, he proclaimed, is “to eliminate virulent polio viruses by the rapid production of hundreds of millions of resistant intestinal tracts so that these dangerous strains will have no place to multiply.” The international aim: “I would be delighted if [our experience] could provoke interest in the U.S. in live-virus vaccine as the most successful immunizing agent against polio.”

Soviet Progress. Dr. Smorodintsev also described a live-virus vaccine against influenza, made by taking weak laboratory strains and letting them multiply in the respiratory tracts of human volunteers (unidentified). Unlike the polio viruses, these regain some of their former potency, and the final vaccine is too dangerous for children under ten; it gives them a feverish illness like flu itself. But adults get two small doses, one against Asian A and the other against Type B flu, squirted into their nostrils with an atomizer. The Leningrad-made vaccine falls short, Dr. Smorodintsev conceded, because it protects only a half to two-thirds of the vaccinated against flu. But that, he noted, is a great gain against a disease which has laid low from one-quarter to one-half of the people in a community.

Biggest jolt to U.S. complacency came when Dr. Smorodintsev reported that his research team had developed a live-virus vaccine against mumps. It has caused no ill effects, he declared, and has protected 90% of 35,000 children in a three-year trial. And he indicated that U.S. laboratories had better look to their laurels in another field: his Soviet colleagues are hot on the trail of a live-virus vaccine against measles, following a method devised by Harvard University’s Dr. Enders. The U.S. product has not yet been widely tested.