The coronavirus "may never go away", the World Health Organization (WHO) has warned.
Speaking at a briefing on Wednesday, WHO emergencies director Dr Mike Ryan warned against trying to predict when the virus would disappear.
He added that even if a vaccine is found, controlling the virus will require a "massive effort".
Almost 300,000 people worldwide are reported to have died with coronavirus, and more than 4.3m cases recorded.
The UN meanwhile warned the pandemic was causing widespread distress and mental ill health - particularly in countries where there's a lack of investment in mental healthcare.
The UN urged governments to make mental health considerations part of their overall response.
What did WHO say?
"It is important to put this on the table: this virus may become just another endemic virus in our communities, and this virus may never go away," Dr Ryan told the virtual press conference from Geneva.
"HIV has not gone away - but we have come to terms with the virus."
Dr Ryan then said he doesn't believe "anyone can predict when this disease will disappear".
There are currently more than 100 potential vaccinesin development - but Dr Ryan noted there are other illnesses, such as measles, that still haven't been eliminated despite there being vaccines for them.
WHO Director-General Tedros Adhanom Ghebreyesus stressed it was still possible to control the virus, with effort.
"The trajectory is in our hands, and it's everybody's business, and we should all contribute to stop this pandemic," he said.
WHO epidemiologist Maria van Kerkhove also told the briefing: "We need to get into the mindset that it is going to take some time to come out of this pandemic."
Their stark remarks come as several countries began to gradually ease lockdown measures, and leaders consider the issue of how and when to reopen their economies.
Dr Tedros warned that there was no guaranteed way of easing restrictions without triggering a second wave of infections.
"Many countries would like to get out of the different measures," the WHO boss said. "But our recommendation is still the alert at any country should be at the highest level possible."
Dr Ryan added: "There is some magical thinking going on that lockdowns work perfectly and that unlocking lockdowns will go great. Both are fraught with dangers
Abed may have been onto something in Community when he said he couldn't let go of the idea of parallel timelines, some darker than others. Sure, there's an explanation to be had with Schroedinger's equation within the logic of the show and the dice roll that created those universes, but researchers believe they've found evidence of the potential for a parallel universe in high-energy particles found in Antarctica, according to New Scientist.
The researchers were perplexed by "a fountain of high-energy particles erupting from the ice" in Antarctica at NASA's Antarctic Impulsive Transient Antenna (ANITA). The phenomenon detected is "in pretty strong tension with the standard model of physics," University of Hawaii Physics and Astronomy Professor Peter Gorham said in 2018. These high-energy particles arrive from space, but cannot pass through the solid mass of the Earth. Yet, instead of detecting these particles coming from space or reflecting off the ice, ANITA has found them coming up from the ice. Low-energy neutrinos, per New Scientist, can pass through solid matter like the Earth, but that's not the case with high-energy neutrinos.
ANITA is a stratospheric balloon designed to detect cosmic-ray showers through radio-wave signals as they bounce up or down off the ice. It turns "an entire continent... into a gigantic neutrino telescope." ANITA has twice detected a "fountain" of high-energy particles coming up from the Earth's surface in years past, with the first time occurring in 2016. The rays resemble an "upside-down cosmic-ray shower," says Gorham. "What we saw is something that looked just like a cosmic ray, as seen in reflection off the ice sheet, but it wasn't reflected," he says. "It was as if the cosmic ray had come out of the ice itself. A very strange thing."
The phenomenon has been reviewed and more easily digestible explanations have been largely ruled out, according to the report, which hypothesizes that the particles may have been traveling back through time, providing theoretical evidence of a parallel universe. New Scientist explained that the "signal requires the existence of a topsy-turvy universe created in the same big bang as our own and existing in parallel with it. In this mirror world, positive is negative, left is right, and time runs backwards." It would be a universe "made of antimatter rather than matter."
The data is still being assessed, and they haven't completely ruled out the possibility that the data is the result of a malfunction with ANITA, per Newshub. Gorham also said that the phenomenon could be "a new class of subatomic particle" that can penetrate all the way through the Earth.
With the options left on the table, none of which include our universe's connection to His Dark Materials, researcher Ibrahim Safa put it bluntly to the New York Post, saying, "We're left with the most exciting or most boring possibilities." The team is still analyzing the latest data from ANITA but hasn't shared its latest findings. "We don't know how to represent it yet," Gorham told New Scientist, "but we've got something."