MONTREAL -- Quebec's vaccination numbers are not enough to ward off the Delta variant, according to the Quebec Institute of Public Health (INSPQ).

"The Delta variant, which is more contagious than the original virus and the Alpha variant currently prevalent in Quebec, has emerged and will likely be the dominant strain in the coming weeks," it indicates. "Vaccine coverage in the Quebec population does not currently appear to be sufficient to effectively counter the threat of the Delta variant, according to current knowledge."

As of Aug. 3, 83 per cent of the eligible population aged 12 and older in Quebec has received one dose of a vaccine; 67 per cent has received two doses.

From July 1 to Aug. 4, Quebec has seen an increase of 301 Delta variant cases, compared to 199 of the Alpha strain, 21 of the Beta and 44 of Gamma.

The INSPQ notes that people who are fully vaccinated "seem to have effective coverage" against most variants, including the Delta strain. Nevertheless, "several uncertainties persist and in this context, caution is warranted."

Given the forecast about the Delta variant, public health officials are recommending people keep a safe distance of two metres from each other in the workplace. 

"In the workplace, where interactions are often more frequent, unavoidable and of longer duration, the SAT COVID-19 workgroup and the INSPQ recommend maintaining a minimum distance of two metres both indoors and outdoors," the institute states. "When this distance cannot be maintained due to the nature of the tasks, it is recommended that adequate physical barriers be installed or that a quality mask be worn."

It acknowledges that over the last few months, the Quebec government has allowed a certain lifting of restrictions, including keeping a one-metre distance in green zones.

However, it points out that working is a "mandatory activity" for most people and Quebec's occupational health and safety law (LSST) must "protect the health and ensure the safety and physical integrity of workers."

The INSPQ states numerous researchers have found that the transfer of SARS-CoV-2 is primarily still through close contact (less than two metres) for a prolonged period of time (more than 15 minutes).

"Inhalable aerosols account for a significant portion of this close contact transmission," it explains. "In some special circumstances -- prolonged contact in small, crowded, inadequately ventilated spaces -- transmission can occur at distances greater than two metres."

The advice from the INSPQ comes with numbers steadily remaining over 100 since July 28.

In addition, public health officials tell CTV News they are unable to provide a breakdown of whether people currently being infected with COVID-19 are vaccinated or not.

"Our team is working to get more data on our website," the INSPQ confirmed.

As of July 28, the INSPQ states people who have been in contact with someone diagnosed with COVID-19 for at least 15 minutes, and within a two-metre distance, must isolate unless both subjects were wearing a mask or there was a physical barrier between them.

This applies to meetings both indoors and outdoors as the modes of transmission are estimated to be the same, though there is less documentation for cases outside.

"Outdoors, there is a dilution effect of particles by ambient air movement and this effect increases with distance," it explains. "This dilution effect decreases the likelihood of outdoor transmission with increasing distance. However, the lack of conclusive data on the magnitude of the dilution effect on outdoor transmission makes it impossible to specify at what distance and under what conditions this effect will be felt."