As daily new cases of COVID-19 in Ontario begin to creep over 800 again, another health official in the province is warning that we could see more lockdowns this fall if certain measures aren't taken.

Dr. Beate Sander is among the experts on the province's COVID-19 Science Advisory Table, responsible for the modelling projections that have been released to inform public health and safety policy, such as business closures and other restrictions.

Though modelling is somewhat of an inexact science that has predicted worst-case scenarios that have not come to fruition, experts agree that we are already in a fourth wave of the virus, which could get dire very quickly despite our already high vaccination numbers.

The latest numbers from the table, released just this week, show that the province could see up to 9,000 new cases of the virus per day if the spread is not mitigated.

Nope…. Not doing that again

— Sandra Payne (@SandraPayne16) September 2, 2021

The group recommends continuing with masking, mass vaccination and working from home, as well as implementing earlier restrictions such as capacity limits in indoor settings and cutting down on large gatherings and events.

This is all in an effort to reduce contacts, which Sander is reiterating as absolutely crucial to prevent shutting down parts of the economy once more — something that proved to be extremely harmful for people's health, and that Premier Doug Ford said would never happen.

"Long weekend, re-opening of workplaces and education in Sept. will INCREASE number of contacts and hence transmission. Meaning without further interventions, our trajectory will be between the current trajectory and the worst-case scenario," Sander tweeted in a lengthy thread on the topic on Thursday.

"We need to REDUCE CONTACTS to this year's late June/early July levels (~70% compared to pre-pandemic) to mitigate the 4th wave," she continued, adding that if we can't surpass a vaccination level of 85 per cent of the eligible 12+ population, we will "need to reduce contacts even further."

If we don't, the doctor believes a lockdown this season is "inevitable."

It DOES MEAN we need to SLOW DOWN now. Delta is like driving on an icy road, traveling fast means we need to break hard at the Stop sign ahead of us. Traveling slower means we won’t need to break as hard and have more time to react. 10/n

— Dr. Beate Sander (@BeateSander) September 2, 2021

At current, some 77 per cent of Ontarians 12 and over are double dosed. Meanwhile, experts are estimating contact levels in August to be 83 per cent. In September, with schools reopening and more events scheduled, they will be greater.

The announcement of the province's vaccine passport on Wednesday has already prompted higher immunization uptake among those still left to get jabbed, though it has also led to protests and further division.

Hopefully, even a slight increase in vaccination rates will mean we can avoid any return of the heavy-handed lockdown measures it feels like we only just escaped from.