Omicron Helps to Shatter Infection Records

The rapidly spreading Omicron variant and its viral competitor, the Delta variant, are setting new case records globally and in the U.S.

3 minute read

December 31, 2021, 6:00 AM PST

By Irvin Dawid


An image showing a smart phone with information from the World Health Organization about the Omicron variant of the coronavirus.

Tada Images / Shutterstock

Infections from the Omicron and Delta variants have topped the previous infection record set by a close descendant of the original strain of the coronavirus, reports Jinshan Hong for Bloomberg Prognosis on Dec. 27, 2021.

The more than 1.44 million worldwide infections smashed the prior record after factoring out a day in December 2020 when Turkey backdated a significant number of cases. A more conservative gauge -- the seven-day rolling average that smooths out one-time fluctuations and holiday reporting irregularities -- is also at an all-time high, owing to a tidal wave of omicron infections.

The highly mutated and most transmissible variant yet, omicron is fast becoming the dominant strain globally as it evades immunity normally provided by vaccines and previous infections. The seven-day rolling average of cases on Monday stood at about 841,000, a jump of 49% from a month ago, when omicron was first identified in southern Africa

The New York Times global tracker recorded the 7-day average for Wednesday (Dec. 29) at 1.015 million, +62% in the past 2 weeks. The daily average of deaths was 6,200, [–14%] in the past 2 weeks.

"Governments already are warning that infections and hospitalizations may soar following the holidays, setting a grim tone as the world heads into the third year of the pandemic," adds Hong.

The silver lining is that daily Covid deaths haven’t significantly increased. The seven-day rolling average of deaths has hovered at about 7,000 since mid-October after falling from a delta-driven peak, despite the emergence of omicron. 

U.S. infection record 

A record was also set in the U.S.on Monday with over half a million cases recorded according to The New York Times U.S. coronavirus tracker (click on their interactive graph titled, "New reported Cases"), meaning that over a third of the global cases recorded on Dec. 27 were Americans. The seven-day average for Dec. 28, 267,000, broke last winter's record set on Jan 11, 2021, of 251,000.

On Dec. 29, average daily cases had already topped 300,00, up 153% in the past two weeks.

In keeping with the guidance noted in a recent post given by Dr. Ashish Jha, dean of the Brown School of Public Health, here are the other two health metrics for Wednesday to consider during the Omicron wave:

  • Hospitalizations: 75,500 (7-day average), +11% in past 2 weeks
  • Deaths: 1,200 (7-day average), [–7%] in past 2 weeks

Not all Omicron

In an unusual correction, the U.S. Centers for Disease Control and Prevention revised the share of infections resulting from the two prevalent variants. Nathaniel Weixel of The Hill reports on Dec. 28:

According to agency data, omicron accounted for about 59 percent of all U.S. infections as of Dec. 25. Previously, the CDC said the omicron variant comprised 73 percent of all cases for the week ending Dec. 18. But that number has now been revised to 22.5 percent of all cases.

The new estimates mean that while a majority of new infections are attributed to the omicron variant, the delta variant has not been sidelined, and still accounts for about 41 percent of infections. 

Weixel reminds us what to expect from so-called 'mild infections' due to Omicron which is considered to be less virulent than Delta.

While evidence appears to show an omicron infection may be more mild for people who are fully vaccinated, experts say the experience is not likely to be pleasant, and people with such infections should expect to be sick for multiple days.

Related in Planetizen:

Monday, December 27, 2021 in Bloomberg Prognosis

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Get top-rated, practical training

Close-up of "Apartment for rent" sign in red text on black background in front of blurred building

Trump Administration Could Effectively End Housing Voucher Program

Federal officials are eyeing major cuts to the Section 8 program that helps millions of low-income households pay rent.

April 21, 2025 - Housing Wire

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

April 30, 2025 - Diana Ionescu

Ken Jennings stands in front of Snohomish County Community Transit bus.

Ken Jennings Launches Transit Web Series

The Jeopardy champ wants you to ride public transit.

April 20, 2025 - Streetsblog USA

Close-up of white panel at top of school bus with "100% electric" black text.

Driving Equity and Clean Air: California Invests in Greener School Transportation

California has awarded $500 million to fund 1,000 zero-emission school buses and chargers for educational agencies as part of its effort to reduce pollution, improve student health, and accelerate the transition to clean transportation.

April 30 - California Air Resources Board

Aerial view of Freeway Park cap park over I-5 interstate freeway in Seattle, Washington at night.

Congress Moves to End Reconnecting Communities and Related Grants

The House Transportation and Infrastructure Committee moved to rescind funding for the Neighborhood Equity and Access program, which funds highway removals, freeway caps, transit projects, pedestrian infrastructure, and more.

April 30 - Streetsblog USA

"No Thru Traffic - Open Streets Restaurants" sign in New York City during Covid-19 pandemic.

From Throughway to Public Space: Taking Back the American Street

How the Covid-19 pandemic taught us new ways to reclaim city streets from cars.

April 30 - Next City