Contagious subvariants dominate COVID-19 rates

Highly contagious BA.4 and BA.5 subvariants now make up more than 70% of all COVID-19 cases in the Region 5 area that includes Chicago.

• The rate is calculated by running thousands of samples through genomic sequencing.

Why it matters: The subvariants appear to be able to reinfect vaccinated people and even those who've recovered from recent Omicron infections.

• They have also driven infection surges in South Africa and are gaining prevalence in Europe.

By the numbers: The Great Lakes states making up Region 5 are reporting an average of around 77,000 cases a week, but those figures don't count home tests.

What's next: An FDA committee is considering a vaccine strategy to protect against the subvariants, but the timetable is unclear.