This progress was enabled by rapid vaccine rollout, with most Western European countries and Canada overcoming their slower starts during the first quarter of and passing the United States in the share of the population that is fully immunized.
However, even that share has been too small for them to achieve herd immunity, because of the emergence of the more transmissible and more lethal Delta variant and the persistence of vaccine hesitancy. Among high-income countries, cases caused by the Delta variant reversed the transition toward normalcy first in the United Kingdom, where a summertime surge of cases led authorities to delay lifting public-health restrictions, and more recently in the United States and elsewhere.
The Delta variant increases the short-term burden of disease, causing more cases, hospitalizations, and deaths.
Our own analysis supports the view of others that the Delta variant has effectively moved herd immunity out of reach in most countries for now, although some regions may come close to it. While the vaccines used in Western countries remain highly effective at preventing severe disease due to COVID, recent data from Israel, the United Kingdom, and the United States have raised new questions about the ability of these vaccines to prevent infection from the Delta variant.
Serial blood tests suggest that immunity may wane relatively quickly. This has prompted some high-income countries to start offering booster doses to high-risk populations or planning for their rollout.
Data from the US Centers for Disease Control and Prevention also suggest that vaccinated people who become infected with the Delta variant may transmit it efficiently. These events and findings have raised new questions about when the pandemic will end.
Beyond that, a more realistic epidemiological endpoint might arrive not when herd immunity is achieved but when countries are able to control the burden of COVID enough that it can be managed as an endemic disease. Raising vaccination rates will be essential to achieving a transition toward normalcy. Vaccine hesitancy, however, has proven to be a persistent challenge, both to preventing the spread of the Delta variant and to reaching herd immunity.
Vaccines are also likely to be made available to children in the coming months, making it possible to protect a group that comprises a significant share of the population in some countries. In this article, we review developments since our March update, offer a perspective on the situation and evidence as of this writing, and present our scenario-based analysis of when a transition toward normalcy could occur.
We have written previously about two endpoints for the COVID pandemic: a transition toward normalcy, and herd immunity. The transition would gradually normalize aspects of social and economic life, with some public-health measures remaining in effect as people gradually resume prepandemic activities. Many high-income countries did begin such a transition toward normalcy during the second quarter of this year, only to be hit with a new wave of cases caused by the Delta variant and exacerbated by vaccine hesitancy.
VOA Newscasts Latest program. VOA Newscasts. Previous Next. July 31, AM. VOA News. The billionaire philanthropist has been very outspoken about how the world should combat the Covid pandemic since it began last March. Since January, more than In the U.
Climate change, caused by the burning of fossil fuels such as oil, gas and coal, is also among the major threats cited by the Doomsday Clock authors. Globally, the year tied with as the hottest on record. At the same time, they also warned of the worsening spread of disinformation and conspiracy theories, which would serve as a multiplier to the worsening threats of nuclear conflict and the climate emergency.
Doomsday Clock: seconds until the end of the world Since , the Bulletin of the Atomic Scientists annually adjusts its symbolic Doomsday Clock, which indicates how close humanity and the planet are to complete disaster.
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