Albert Kapikian of the NIH, for example, identified a rhesus strain of virus, and Fred Clark and Stanley Plotkin of Wistar identified another bovine strain that might replicate more vigorously.

• 例如NIH的卡匹肯找到一种恒河猴病毒品系，威斯塔研究所的克拉克及普洛金则找到另一种能积极复制的牛病毒。