The Taxonomic Position of Common Cold Viruses and Some Others

During recent years workers in several countries have isolated a number of "new" viruses from upper respiratory infections. For some of these viruses claims have been made that they cause common colds. Before accepting such claims it is well to be sure of two things: i) that the viruses can be recovered with reasonable frequency from typical common colds in adults; and ii) that they will reproduce typical common colds in volunteers. The second criterion is more easily fulfilled. Workers at the Common Cold Unit at Salisbury have produced cold-like symptoms in volunteers with the following viruses propagated in tissue cultures or in fertile eggs: Influenza A; Parainfluenza 1 and Parainfluenza 31; ECHO 112; ECHO 20; ECHO 28 (JH or 2060)2; Coe virus4; Adenovirus5. With most of these viruses, the colds produced were not quite typical, particularly when attention was given to the whole group of inoculated persons and not only to individuals. For instance, the adenoviruses and parainfluenzas gave rise to numerous cases of fever; ECHO 11 and 20 caused gastro-intestinal as well as respiratory symptoms (usually sore throats). The Coe virus, however, produced typical colds; so too did Echo 28, though the earlier results were hard to interpret. On the other hand, most of these viruses were not isolated from typical colds. The parainfluenzas in particular came mainly from minor respiratory infections in children, while the adenoviruses, Coe virus, and some others were most frequently from outbreaks in recruits. During fifteen years' work at Salisbury, none of these viruses has been recovered from nasal washings from typical naturally-occurring colds in adults, though such washings will reproduce colds in a high proportion of volunteers. Several strains of Echo 28 have recently been isolated, however, from washings from colds in children. All things considered, the Salisbury workers did not feel that typical common cold viruses were being dealt with. Then, in 1960, it was reported that some rather different viruses had been cultivated from colds