Both deaths were linked to vapes containing THC, the psychoactive compound in cannabis, bought at legal shops in the US state, according to the Oregon Health Authority.
In the most recent death, the person was hospitalised with respiratory problems after vaping products that contained the cannabinoid.
The fatalities have led to calls for people to stop vaping and for a temporary ban on the sale of the products in Oregon.
Health officer Dr Dean Sidelinger warned: “People should stop vaping immediately.
“If you vape, whether it’s cannabis, nicotine or other products, please quit. If you haven’t started vaping, don’t start.”
Meanwhile, lawmaker Cheri Helt asked governor Kate Brown to immediately issue a temporary ban on the sale of all vaping products until health experts better understand the cause of the illnesses.
Ms Helt, a Republican from the small city of Bend, in Oregon, said in a statement: “Oregon needs an immediate pause in sales and stronger, longer-term regulation of all vaping-related products to save lives, prevent addiction and protect public health.”
Oregon has so far linked five cases to the national outbreak of severe lung injury thought to be caused by vapes and e-cigarettes. The state’s first death occurred in July and was announced on 3 September.
Those who have fallen ill in the state have been hospitalised after experiencing worsening symptoms, including shortness of breath, cough or chest pain.
Nationally, there have been 805 cases, mostly among youths and young adults, in 46 states and one US territory, according to the US Centres for Diseases Control and Prevention (CDC).
A total of 13 additional deaths, including Oregon’s first fatality, have been reported in 10 states.
The confirmed deaths include two in California, two in Kansas, two in Oregon and one each in Florida, Georgia, Illinois, Indiana, Minnesota, Mississippi, and Missouri.
In 373 of the cases, three-quarters of the victims were male, two-thirds were 18 to 34 years old and 16 per cent were minors, according to the CDC.
Health officials in California, home to the world’s largest legal cannabis marketplace, this week issued a public advisory urging people to stop all vaping.
Massachusetts, which like California allows so-called recreational use of marijuana by people 21 and older, went further than any other state, issuing a four-month ban on vape sales.