IHME forecasts enormous spread of Omicron

New Delhi: Institute for Health Metrics and Evaluation (IHME), an independent global health research centre at the University of Washington has released a research report on Omicron, a variant of SARS-CoV-2.

Comparing the Omicron variant with the Delta variant IHME research says that the Omicron is more transmissible and with 40-60% immune escape combine to lead to rapid increases in reported case counts. A much larger fraction of infections is symptomatic – likely up from 40% for Delta and prior variants to 90-95% for Omicron.

However, it also shared that based on the best available data, the infection-hospitalization rate is dramatically lower (note the infection-hospitalization rate is not the case-hospitalization rate), likely 90-96% lower than for Delta. The infection-fatality rate is dramatically lower, likely 97-99% lower than for Delta.

The research also forecasts around 3 billion infections to occur in the next 2 months. That’s as many infections as was seen in the first 2 years of the pandemic. Peak transmission should be in mid-January with over 35 million global infections a day, nearly three times the Delta wave peak in April. Given the immune escape and transmissibility, eventually Omicron will reach all country soon, shares the IHME research report. Even countries with strict border controls like New Zeeland based on the Delta experience are likely to eventually see Omicron surges in all country including China we expect in the future. Detected infections at the global level will reach 3 times previous peaks.  In the US, the peak will be over 400,000 a day.

The analysis by IHME shows that increasing mask use to 80% will have a huge effect on cases, hospitalizations, and deaths. More rapid and extensive delivery of third doses of vaccine will also reduce the burden of hospitalization and death. The unvaccinated and never infected are at greatest risk. Vaccination for the unvaccinated is a powerful way to reduce personal risk.

Given the rapid spread and increase in Omicron and the high fraction asymptomatic combined with much lower infection-hospitalization and infection-fatality rates, employers and schools will need to re-evaluate their approach to testing and quarantine. Going forward, tracking hospitalizations rather than reported cases will be a more relevant measure for local action than case counts.