Why does a virus particle need to be purified in order to determine the sequence of its genome? There is absolutely no doubt that we have the viral sequence.Did they purify to a particle that could transmit illness?
Do you believe that conjectured particle actually hijacks cell replication and bursts cells?
And how would you assess the ability of that supposedly purified particle to transmit illness without injecting it into a susceptible person?
And what is your means for assessing "purity"?
Viruses can definitely be lytic, but many are not. All viruses, however, hijack cellular genes to assist in their replication.