New modelling suggests that the Omicron wave has plateaued in Ontario or is in a decline but COVID-related hospitalizations are expected to rebound with a “prolonged peak” after reopening with increased contacts.
In documents released on Tuesday, Ontario’s COVID-19 Science Advisory Table noted that recent changes in testing eligibility made it challenging to model the spread of the virus as they had done in the past and instead focused on other key indicators.
For example, the science table used wastewater signal which they said likely peaked around Jan. 4.
Taking into account a time lag of diagnosis and reporting, the province’s wastewater signal of Jan. 4 would correspond to a peak in cases around Jan. 11, the documents read.
It also noted a “plausible range” for COVID-19 infections that have occurred since Dec. 1 — based on wastewater signal — is 1.5 to 4 million infections.
The science table also said that it expects hospitalizations to rebound after reopening on Jan. 31 and remain at a “prolonged peak.”
The prolonged peak for hospitalizations could stretch into March, based on the trajectories modelled.
Different modelling scenarios all took into account an increase in contacts between people as the province loosens public health restrictions. It also looked at different levels of community immunity gained through the Omicron wave. And some models assumed that around 8 million people would have received a booster. As of Tuesday, more than 6.4 million Ontarians are boosted.
Only under the most favourable assumptions would hospitalizations start to decline, the table noted.
COVID-19 hospitalizations have risen across all age groups and have reached an all-time high, the science table said.
“Hospitals are now caring for the highest number of people with COVID- 19. Admissions are at highest levels across all age groups. ICU occupancy continues to be high. Staffing in hospitals remains critical,” the science table said.
The science table said surveillance will be important in detecting changes in the pandemic’s trajectory.
“Omicron appears to affect the upper respiratory tract more than the lower respiratory tract, and therefore may have a different clinical course than previous variants, which may affect hospital and ICU admissions and lengths of stay,” the documents read.
Although testing is limited, based on the testing that is being done, test positivity has declined suggesting Ontario is past the peak of the Omicron wave.
The science table also said vaccination continues to be highly effective at preventing severe outcomes such as landing in hospital or ICU.
“Unvaccinated people currently have a 6-fold higher risk of being in the hospital and 12-fold higher risk of being in the ICU compared to people who received 2 or 3 doses of a COVID-19 vaccine” the science table wrote.
— More to come.
Comments