Editor's Note: The following is a summary of new Oliver Wyman analysis about recent COVID-19 vaccination considerations for business leaders. Read our full analysis here: The Long Haul to Normalcy.

The fourth quarter of 2021 is likely the earliest we get close to “back to normal” in the United States, according to recent Oliver Wyman analysis, even with the promising vaccine efficacy news. Companies must consider if what has been working for the past seven months can be sustained for the next 12 to 15 months. They must also consider what they may need to adjust.

The key to “getting back to normal?” Cumulative immunity. There are several dimensions to this that need to be considered. One is the percentage of the population that has already been infected and has protective immunity. Another is the percentage of the population that is either naturally immune to infection or has been effectively vaccinated. We need enough cumulative immunity present in the population to stop the virus from spreading.

In The Long Haul to Normalcy, which leverages our Pandemic Navigator and a team of infectious disease experts, we provide four possible scenarios on when the appropriate threshold immunity can be achieved and share the key levers that impact timing – both hindrances and accelerants. The research also offers business leaders three “no regret” moves to aid their planning and response efforts.

SOME SCENARIOS TO CONSIDER IN THE US

There are many possible paths to the HERD IMMUNITY threshold. Each example below represents only one of many possible pathways to herd immunity threshold; pathways become more distinctive and flexible the further out the target date.

Source: Oliver Wyman analysis