Of Delta-cron & Milder-cron

Since the Omicron variant of Covid-19 was named by WHO on November 26, 2021, it has moved at lightning speed. In less than three months, Omicron has spread around the world, caused record peaks in cases in many places, and is now declining just as quickly....

Prospects for the rest of the year and beyond hinge on the questions of whether and when future variants will emerge.... A new dominant variant will receive a Greek-letter name, but, until then, we have created more descriptive names for our scenarios. Under the 'Omicron's twin' scenario, a variant that evaded prior immunity (including from Omicron) but was otherwise similar to Omicron in transmissibility and severity of disease might cause a wave of disease broadly similar to the one we have recently experienced....

A worse case might be 'Delta-cron', a variant that evades prior immunity and combines the infectiousness of Omicron with the average severity of Delta. This might occur if vaccines proved less effective in preventing severe disease, and could lead to the worst wave yet for many locations.


The 'Milder-cron' scenario would continue the trend toward less severe disease. Countries might then experience a smaller version of the recent Omicron wave, which might be managed similar to the way societies manage flu on an ongoing basis.

From 'When Will the Covid-19 Pandemic End?', McKinsey & Co