Experts stepped in to appease public worry after news outlets reported there have been six deaths and 450 cases of a severe respiratory illness, thought to be linked to vaping, across 33 states of America.

The patients were reported to be mostly young people with symptoms including shortness of breath, coughing, fever, fatigue and vomiting.

Of those hospitalized, many admitted to vaping a variety of substances including marijuana-based products and do-it-yourself brews, not regulated products.

US investigators are yet to establish the exact cause, but samples taken from patients with the condition showed high levels of vitamin E acetate, used as a thickening agent on the black market, which is commonly used to vape cannabis products.

In light of the news, the US government's Food and Drink Administration (FDA) has now advised the public to stop vaping THC specifically, the marijuana compound that produces a "high".

While some US states, which have legalized recreational marijuana for adult-only and medicinal use, oversee the products, the central government's FDA doesn't regulate it, meaning the black market has become flooded.

The FDA, the Centres For Disease And Control and Prevention (CDC) and US department of Health & Human Services (HHS) has also advised the public that cannabis vape products bought off the streets are untested, unregulated and could be contaminated.

Officials have also warned those who own illicit vape cartridges to throw them away immediately.

Health experts in both the US and UK have likewise stepped in to reassure regular vape users not to be concerned about using regulated vaping products and reiterated the concern is more with illegal substances and practices.

The FDA's former chief Dr. Scott Gottlieb said earlier this week the US government had put in a lot of work to ensure vape users buying regulated products are safe.

He wrote on Twitter: "The legal vapes have been actively regulated by FDA since Aug 2017. FDA has conducted thousands of inspections of manufacturers and vape stores, published manufacturing guidance, sought product removals etc. These tragedies point to illegal vapes and THC."

He added that health officials can target imports and conduct blitzes at international mail facilities to try and capture, shut down more illegal and counterfeit vapes and source some of the dangerous products.
There are already published FDA lists of known dangerous ingredients to look for.

Vapers in the UK have also been reassured by government body Public Health England, which has previously reported vaping is 95 per less harmful than smoking cigarettes that it is safe to vape, as long as it's from a reputable source.

Martin Dockrell, head of Tobacco Control at PHE, advised all vapers to use tightly regulated e-cigarette and vape products, saying: A full investigation is not yet available but we've heard reports that most of these cases were linked to people using illicit vaping fluid bought on the streets or homemade, some containing cannabis products, like THC, or synthetic cannabinoids, like Spice.

He added: "Our advice remains that e-cigarettes are a fraction of the risk of smoking, and using one makes it much more likely you'll quit successfully than relying on willpower alone.

"But it's important to use UK-regulated e-liquids and never risk vaping home-made or illicit e-liquids or adding substances, any of which could be harmful.”

Professor Linda Bauld, a public health expert at Edinburgh University, was also quoted in British newspaper The Guardian as saying: It seems highly unlikely that widely available nicotine-containing vaping products, particularly of the type regulated in Europe, are causing these cases.

All the evidence to date suggests that illicit marijuana vaping products (THC oils) are the cause. In particular, a compound called tocopherol acetate may be the culprit.

The US government's Centres For Disease And Control and Prevention (CDC), who is undertaking the investigation, along with the American Medical Association (AMA) who have been urging consumers to avoid vaping altogether, has also come under fire.

Gregory Conley, president of the American Vaping Association, criticized the AMA for "fear mongering about nicotine vaping products" and not mentioning "the very real risks of vaping illicit THC products".

Critics are also concerned the CDC's blanket advice serves more of an instruction to smokers to keep smoking tobacco than helping to prevent further hospitalizations of those who are vaping black market THC products.

Public health expert Dr. Michael Siegel, a leading doctor and researcher at the Boston University School of Public Health called it irresponsible adding: ":There are millions of people who are vaping nicotine-containing e-liquids and it would not be prudent for these millions of people to return to smoking in order to avoid the risk of this "unknown" and "mysterious" medical condition.

"Moreover, with such vague advice, no one is likely to change their behaviour because they are not being warned about any specific, identifiable risk."

Public Health England added that e-cigarettes remain a fraction of the risk of smoking and advise vapers to take sensible choices when vaping such as buying from a reputable source and ensuring they are properly regulated products.