Though the World Health Organization has not yet established clear measures for when a pandemic has ended, officials have previously cited criteria such as vaccine development and evidence of herd immunity.

World Health Organization (WHO) Director-General Dr. Tedros Adhanom Ghebreyesus declared the COVID-19 outbreak a global pandemic on March 11, 2020, based on an increase in cases outside of China, according to the National Library of Medicine.

Ghebreyesus said that progress on effective vaccines against COVID-19 should give people hope, but warned that the pandemic is far from over, according to the United Nations News on Dec. 4.

“The pandemic still has a long way to run and decisions made by leaders and citizens in the coming days will determine both the course of the virus in the short term, and when this pandemic will ultimately end,” Ghebreyesus said, according to UN News.

“It will take a long to beat it (the Coronavirus)” @JoeBiden at the END of his Presser when he starts talking about COVID. He puts on the mask to say we are still going to be dealing w/ the virus in the SUMMER & EARLY FALL.

He could have worn the mask the entire time. #politics pic.twitter.com/IbnzllwI47

— PARIS (@PARISDENNARD) January 25, 2021

Ghebreyesus has not yet specified the standards for declaring an end to the pandemic, according to the WHO.

Pandemics and epidemics such as Ebola and H1N1 or “Swine Flu” have previously been declared over after a decline in outbreaks and some evidence of herd immunity, according to the WHO.

Former WHO Director-General Margaret Chan declared an end to the H1N1 influenza pandemic after consulting with an emergency committee in August 2010, according to MedPage Today. Chan said that the “virus has largely run its course,” and that it would likely appear similar to the seasonal flu “for some years to come.”

Chan added that serious outbreaks of H1N1 were still possible and that people should continue getting vaccinated despite announcing an end to the pandemic, according to MedPage Today. The decision to officially end the pandemic was made by considering the lack of outbreaks that occurred over the summer, data that showed outbreaks mirrored the intensity of the seasonal flu and some evidence of community immunity that suggested between 20% and 40% of the population had been infected.

The 11th Ebola outbreak went on for six months before it was controlled and ended by mass vaccinations that began four days after the report of the epidemic, according to the WHO. Over 40,000 people who were at high risk of infection were vaccinated, there were 119 confirmed cases, 55 deaths and 75 recoveries reported with the outbreak.

Herd immunity is achieved through vaccination or developed immunity to a disease, according to the WHO. Herd immunity to COVID-19 should be developed through vaccinations which activate an individual’s immune system to produce antibodies, though it is unknown what percentage of the population would need to be vaccinated against COVID-19 to achieve herd immunity.

“This is an important area of research and will likely vary according to the community, the vaccine, the populations prioritized for vaccination, and other factors,” according to the WHO. “Globally, data from seroprevalence studies suggests that less 10% of those studied have been infected, meaning that the vast majority of the world’s population remains susceptible to this virus.”

Around 4.7 million new cases were reported in the last week, a 6% decrease from last week, according to the WHO. New deaths reached a record high with 93,000 reported, over 2 million people have died of COVID-19.

The U.S. reported 1,583,237 new cases last week, an 11% decrease from last week, according to the WHO. (RELATED: COVID-19 Antibody Cocktail Effective At Preventing Symptomatic Infections)

Countries began reporting a new variant strain of COVID-19 on Jan. 19 in Brazi, several countries responded by implementing additional travel restrictions, according to the WHO. An international team of scientists is reviewing research to determine the origin of the virus in China.

Professors Susan Allen, Steve Buka, Simin Liu, Stephen McGarvey and Tongzhang Zhen from Brown University did not respond to the Daily Caller News Foundation’s request for comment.

Colby McCoy contributed to this report.        

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