A link between brain tumors and a CMV strain of herpes has been confirmed in at least three new studies, triggering the launching of a CMV vaccine trial in California.

According to The San Francisco Chronicle cancer researchers have acted on a hunch that surfaced a decade ago, linking this CMV strain - that lies dormant in 80% of infected Americans - to cancerous brain tumors.

The young physician responsible for bringing forward this theory speculated that patients with brain cancer appeared to be mostly affluent and educated and were more vulnerable to common viruses such as the CMV Herpes strain because of their 'hyper-hygienic' lives.

CMV vaccine trials have begun for chemo patients leaving several recipients tumor-free after two years; which is un-common for a cancer such as this, that normally returns within months of treatment in 95% of cases.