You just got your vaccine shot. You’re feeling great. Is it okay to celebrate with a joint? How long should you wait to fire one up?

Since COVID-19 is a respiratory disease, caution is advised. The research that’s out there suggests it’s a good idea to wait a few days after your shot to begin indulging—at least until the swelling in your arm is gone. Also, it will take a few days for any side effects from the vaccine (flu-like symptoms, for example) to subside.

If you’re a medical marijuana user and require cannabis for a condition, then the situation is more complicated. Here edibles are an option for some, but not others who rely on the immediate psychoactive punch delivered by smoking to help with pain relief and other conditions. Over-the-counter pain killers containing ibuprofen and acetaminophen are another option for medpot patients in the short-term.

If you happen to be over 65 or have an underlying medical condition, other considerations come into play, since the older you are the more susceptible you are to effects of the virus. Coincidentally, Canadians over 65 also happen to be the largest growing age groups among cannabis users and most of those are using it for various conditions.

Most medical experts agree that smoking in general may reduce the vaccine’s effectiveness against the virus. But there hasn’t been enough written on the subject of cannabis to know to what extent weed may hinder vaccine protection against the virus.

There’s some research to indicate cannabis’s anti-inflammatory properties may actually provide a layer of protection against the virus, similar to how cannabis helps alleviate the symptoms of some forms of cancer.

A study published in January by the National Center for Biotechnology Information in the U.S., for example, indicates that THC and CBD may help “down-regulate” the “cytokine storm”, the severe and acute inflammation that overwhelms the respiratory pathways in the lungs in serious cases of COVID-19.

In that research, three of seven sativa extracts tested caused “profound and concerted down-regulation of…other cytokines and pathways related to inflammation and fibrosis”. But one of the tested extracts had an effect “that may be deleterious, signifying that careful cannabis cultivar selection must be based on thorough pre-clinical studies”.

The findings are based on modelling and studies performed on mice.

Will smoking cannabis after receiving a vaccine reduce its effectiveness against the disease?

There hasn’t been much written on the subject and even less on edibles. Some published reports suggest there’s anecdotal evidence that smokers are actually less susceptible to COVID-19 for reasons that are not yet known.

The Canadian Centre for Substance Use and Addiction, the federal government advisory body on substance use, advises medpot patients against smoking. In a paper published shortly after the onset of the virus in Canada last year, the CCSA states that “there is no scientific evidence that demonstrates the benefits of either THC or CBD in preventing or treating COVID-19. On the contrary, the evidence shows that inhaling cannabis smoke, as with smoke from other sources such as tobacco, can have negative effects on the respiratory system.”

The CCSA points to one study evaluating risk factors in 78 cases of COVID-19 and found patients who smoke were 14 times more likely to develop respiratory complications from the virus, such as pneumonia.

The same CCSA advice applies to vaping, which is regarded as a less harmful way to ingest cannabis since you’re not inhaling the same amount of carcinogens as by smoking. The issue there is the vitamin E used in cannabis-infused oil products. Heating the substance “can produce carcinogenic alkenes”.

The CCSA says THC from cannabis in general can “inhibit” the body’s immune response to COVID-19, according to pre-clinical trials in rodents and monkeys “THC is able to suppress the ability of immune system cells and immune messengers to modulate an adequate immune response against foreign pathogens such as viruses".

The pandemic has been gangbusters for cannabis sales. Canadians are indulging more than ever.

Cannabis is having a big impact—a positive one—on the mental health of Canadians. But as with many issues involving the coronavirus, the science continues to evolve.

Seven things to remember about COVID-19 and cannabis

1. Do not share joints, vaping devices or bongs.
2. Wash your hands before putting cannabis products in your mouth.
3. If possible, limit your cannabis use to once a week.
4. Avoid inhaling deeply and holding your breath when smoking or vaping.
5. It’s a good idea to ensure your cannabis products are from licensed and regulated producers.
6. Use products that contain no more than 10 percent THC.
7. Consult your health care provider if you are using cannabis for medical purpose or with other medications.

Source: Canadian Centre for Substance Use