I mean "Is it safe to read"
Why on earth would you want to ? The 'message' is of no consequence, it's just there to transport the virus.
I thought a virus was sent from the address book of an infected computer - if I don't know any one of the fifteen (so far) virus senders, then why is my address inside their computer
Typical viruses use both a 'from' and 'to' address culled from an infected system's .pab file. The one you received is from someone who has both your address and the senders' addresses, the apparent sender is a spoof.