Coronavirus updates: 'Close contact' definition updated by CDC
The CDC offered new, more strict guidance on Wednesday.
A pandemic of the novel coronavirus has now killed more than 1.1 million people worldwide.
Over 41.1 million people across the globe have been diagnosed with COVID-19, the disease caused by the new respiratory virus, according to data compiled by the Center for Systems Science and Engineering at Johns Hopkins University. The criteria for diagnosis -- through clinical means or a lab test -- has varied from country to country. Still, the actual numbers are believed to be much higher due to testing shortages, many unreported cases and suspicions that some national governments are hiding or downplaying the scope of their outbreaks.
Since the first cases were detected in China in December, the virus has rapidly spread to every continent except Antarctica.
The United States is the worst-affected country, with more than 8.3 million diagnosed cases and at least 221,987 deaths.
California has the most cases of any U.S. state, with more than 886,000 people diagnosed, according to Johns Hopkins data. California is followed by Texas and Florida, with over 868,000 cases and over 760,000 cases, respectively.
Nearly 200 vaccine candidates for COVID-19 are being tracked by the World Health Organization, at least 10 of which are in crucial phase three studies. Of those 10 potential vaccines in late-stage trials, there are currently five that will be available in the United States if approved.
Latest headlines:
- New CDC study finds multiple, brief exposures within 6 feet can heighten risk of transmission
- New Jersey Gov. Phil Murphy self-isolating after close contact with someone who tested positive
- US surgeon general says herd immunity could 'lead to many complications/deaths'
- Analysis shows rise in COVID-19 hospitalizations in 42 US states
- US reports over 60,000 new cases, nearly 1,000 deaths
NYC mayor says health care personnel, essential workers and vulnerable will get vaccine priority
New York City Mayor Bill de Blasio unveiled a two-phased vaccination plan for the city during a news conference Wednesday.
In Phase 1, when the vaccine is in limited supply, de Blasio said health care personnel, front-line and essential workers, and vulnerable groups will be prioritized.
Phase 2 comprises of the general public, the mayor said.
"The vaccine will be a crucial part of our rebirth and open the economic bridge to our recovery," de Blasio said.
He added that he does not have an exact date of when the phases would happen, and it remains contingent on an approved vaccine, but promised “it will be sooner rather than later.”
New York City's rollout plan is in line with proposed federal prioritization plans, as the push for first dibs on a vaccine is already underway.
Boston Public Schools to suspend in-person learning amid rising positivity rates
Boston will suspend all in-person learning for its public school system, effective this Thursday, Superintendent Brenda Cassellius announced on Wednesday in a letter to employees obtained by ABC News' local affiliate WCVB.
The move came after local health officials said that the citywide seven-day COVID-19 positivity rate had increased to 5.7% -- a jump from 4.5% last week, and 4.1% two weeks before.
“We remain committed to providing in-person learning opportunities to our students as soon as it is safe to do so, and will continue to prioritize out students with the highest needs for in-person learning,” Cassellius wrote.
Boston will resume in-person learning for high-need students in public schools once the seven-day positivity rate is below 5% for two consecutive weeks. A phased-in approach will also begin for the districts youngest students when the positivity rate is below 4% for two consecutive weeks.
The seven-day average of new cases in Massachusetts has been on the rise for nearly seven weeks, increasing by 86% just in the last month.
ABC News' Arielle Mitropoulos contributed to this report.
Russia reports record high of 317 deaths in a day
Russia registered a record 317 deaths from COVID-19 in the last 24 hours, according to the country's coronavirus response headquarters.
The previous record of 286 fatalities from COVID-19 in a 24-hour reporting period was set just last week.
An additional 15,700 new cases of COVID-19 were also confirmed nationwide in the past 24 hours, down from a peak of 16,319 the previous day.
Nearly 28% of the new cases -- 4,389 -- and almost 20% of the deaths -- 63 -- were reported in the capital, Moscow.
The cumulative totals now stand at 1,447,335 cases and 24,952 fatalities, according to Russia's coronavirus response headquarters.
Although Russia has been breaking its own records for daily case counts and deaths almost every day since Oct. 9, authorities there are resisting shutting down businesses again. Few measures have been imposed in Moscow, the epicenter of the country's COVID-19 outbreak and recent surge.
The Eastern European country of 145 million people has the fourth-highest tally of COVID-19 cases in the world, behind only the United States, India and Brazil, according to a real-time count kept by Johns Hopkins University.
ABC News' Alina Lobzina contributed to this report.
US surgeon general says herd immunity could 'lead to many complications/deaths'
U.S. Surgeon General Jerome Adams said Wednesday that a "herd immunity" approach to combating COVID-19 could "lead to many complications/deaths."
Adams posted the comment on his official Twitter account, along with a link to a recent article from The Journal of the American Medical Association entitled "What is Herd Immunity?"
"The summary: Large numbers of people would need to be infected to achieve herd immunity without a vaccine; this could overwhelm health care systems and lead to many complications/deaths," Adams tweeted. "So far, there is no example of a large-scale successful intentional infection-based herd immunity strategy."
Instead, Adams urged people to "wear masks," "wash hands" and "watch distances."
The surgeon general's comments come after the White House embraced a controversial declaration by a group of scientists calling for an approach that relies on "herd immunity."
The so-called Great Barrington Declaration, which claims on its website to have been signed by more than 9,000 medical and public health scientists around the globe, opposes lockdowns and argues that authorities should allow the novel coronavirus to spread among young, healthy individuals while protecting the elderly and the vulnerable.
Dr. Anthony Fauci, the nation’s top expert on infectious diseases, has called the concept "ridiculous" and "total nonsense."