March 29, 2024
BANGOR DAILY NEWS (BANGOR, MAINE

Smallpox gone, not forgotten

From biblical times smallpox had been a scourge of mankind killing millions each year around the world. This began to end in 1798 when Jenner found that inoculations with material from cowpox lesions protected against smallpox. Inoculation programs ended smallpox in the United States in 1950 and the last reported natural case in the world occurred in Somalia in 1977.

In October 1979, the World Health Organization declared the world free of smallpox and formalized inoculation programs ceased. Today, the only known samples of smallpox virus are stored at the Centers for Disease Control in Atlanta and the Research Institute for Viral Preparations in Moscow. The journal Science reports that a fierce debate is raging over whether the last remaining traces of this once worldwide plague should be destroyed.

The argument against keeping the samples is twofold. First, that they are of little scientific value; second, that they pose a threat to a now unvaccinated world population if they should fall into the hands of terrorists. In 1991, biologists in the United States and Russia completely sequenced the genomes, or genetic DNA, of two major smallpox strains. This is sufficient, say scientists, to allow any possible new strain to be identified in the unlikely event one ever surfaces. Moreover, key bits of the smallpox DNA have been inserted into that of bacteria providing a harmless source of reference genetic material for diagnostic purposes. Thus a case cannot be made for keeping the virus for diagnostic purposes and, terrorism aside, a mishap at either repository could have deadly consequences. In 1978, a worker at the University of Birmingham died from accidental exposure to virus kept in a supposedly secure vault some distance from her laboratory.

A third reason given for destroying the stocks is political. There is no guarantee that all nations that agreed to destroy their smallpox viral samples actually complied. Some may have been retained out of suspicion of United States and Russian motives. Destruction of the two remaining stockpiles would send a clear message that their suspicions were unfounded. In fact, the World Health Organization wants to make the mere possession of smallpox virus an international crime.

The arguments to retain the virus are essentially the negative of those to destroy it. Opponents say that three sources of virus still exist and cannot be controlled. One is human cadavers of smallpox victims frozen in permafrost. Such cadavers carry smallpox antigens and are being tested for live virus. Another is viral stock either deliberately stored or forgotten in research laboratories. It is possible that many samples, collected during the eradication program, lay unmarked and forgotten in freezers around the world.

Third, there is a widespread virus, monkeypox, that causes a disease similar to smallpox but is almost never transmitted to humans. This could change with the emergence of HIV lowering human’s defense against monkeypox. Also there is little to prevent the smallpox genes now stored in bacteria from being transferred to monkeypox virus unleashing a new virulent form of smallpox. In essence, goes the argument, destroying the U.S. and Russian stocks will not erase the threat of smallpox from the world.

The benefits of saving the virus is that, while scientists have a blueprint of its genetic makeup, little is known about its mode of invading and replicating itself in the cell. Also, pure virus is required to study why smallpox only attacks human cells. Since this can only be done in living tissue, and not in a test tube or petri dish, one wonders how those who would keep the virus plan on testing these facets of the human-virus relationship. The argument that intact virus contains more information than a mere understanding of its DNA sequence is certainly a sound one however whether that is sufficient to offset its potential danger is the core of the debate.

The World Health Organization’s timetable for destruction of the samples was today (Dec. 31), a date that was almost certainly not met. Time shall tell which side of the argument proves to be most persuasive to the U.S. and Russian governments.

Clair Wood is a science instructor at Eastern Maine Technical College and the NEWS science columnist.


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