One day down, the other day up – this appeared to be the story with the registration of daily coronavirus infections in Pakistan as the country reported 620 cases during the last 24 hours (Tuesday) as compared to 371 the previous day. The pattern with fatalities was the same as four deaths were recorded during the last 24 hours (Tuesday) as compared to one a day earlier, showed the statistics released by the National Institute of Health Pakistan on Wednesday morning.

As per the NIH data, the death toll in the country now moved up to 30,474 after adding the four fatalities (all reported from Sindh) while the number of total infections now stood at 1,551,871 after adding the fresh 620 cases.

During the last 24 hours (Tuesday), 16,704 tests were conducted throughout Pakistan whereas the positivity ratio stood at 3.71 percent. The number of patients in critical care was recorded at 191.

The maximum positivity ratio during the last 24 hours was recorded in Diamir which was at 12.24 percent, followed by Lahore at 7.80 percent and Karachi at 4.41 percent.

https://twitter.com/NIH_Pakistan/status/1552101324723986433

During the last 24 hours (Tuesday), another 588 patients have recovered from the Covid-19 in Pakistan and the number of total recoveries now stood at 1,513,737. As of Wednesday, the total count of active cases in the country was recorded at 7,660.

As many as 590,243 coronavirus cases have so far been confirmed in Sindh, 512,176 in Punjab, 221,063 in Khyber Pakhtunkhwa, 137,221 in Islamabad, 35,756 in Balochistan, 43,563 in Azad Kashmir and 11,849 in Gilgit-Baltistan.

As many as 13,587 individuals have lost their lives to the pandemic in Punjab so far, 8,169 in Sindh, 6,329 in KP, 1,027 in Islamabad, 793 in Azad Kashmir, 378 in Balochistan and 191 in Gilgit Baltistan.

Biden busts out of Covid isolation with gym session

Audio-bombed by a barking pet dog, wondering if he looks OK on video conference, and finally being allowed to hit the gym -- Joe Biden may be the most powerful man in the world but the ups and downs of Covid isolation are the same as for anyone else.

Tuesday was Biden's fifth day confined to quarters and his doctor, Kevin O'Connor, said the president has now completed a five-day course of the therapeutic Paxlovid, with nearly all symptoms of the coronavirus gone.

"His symptoms have now almost completely resolved," O'Connor said in a memorandum.

Biden is expected to be released from isolation once he's had a negative test.

But little question that the 79-year-old is already beyond ready, at least mentally.

While the doctor focused mostly on items like healthy oxygen saturation, pulse and temperature, the line really speaking to Biden's state was that he "feels well enough to resume his physical exercise regime."

Unlike his predecessor Donald Trump, who mused that gyms and the like may actually be bad for you, Biden works out every morning, as well as taking gentle bike rides at home in Delaware on weekends.

"He asked last night to exercise," Press Secretary Karine Jean-Pierre said. "He likes to do weights, he likes to do the treadmills."

- On-screen jokes -

The announcement last week that he had tested positive for Covid-19 meant Biden had to cancel domestic travel plans and reduce work hours in the White House, although staff emphasized that he continues to carry out full duties.

Although he is expected to return to working in person this week, Tuesday was another virtual day, with the president meeting executives from South Korean giant SK on plans to invest $22 billion in semiconductors and other high-tech industries.

While visitors and senior staff gathered in the White House's Roosevelt Room, Biden appeared on a video screen, laughing as he pointed out that he was in fact just a few doors away in the same building.

"I can walk out to the balcony and holler at you," he said.

Between discussing weighty issues of South Korean-US ties, Biden revealed the more human aspects of working from home that would be familiar to much of the planet over the last couple years.

“I'm feeling great. I hope it comes across" on screen, Biden quipped. "I hope I look as good as I usually do, which is not that good."

Then during an exchange with the executives on skilled workforces, a loud dog bark -- possibly Biden's German Shepherd Commander -- was heard interrupting the live feed.

Jean-Pierre said Biden is clearly on the mend.

"It brought a smile to my face when I saw he wants to work out," she said.

Pair of new studies point to natural Covid origin

An animal market in China's Wuhan really was the epicenter of the Covid pandemic, according to a pair of new studies in the journal Science published Tuesday that claimed to have tipped the balance in the debate about the virus' origins.

Answering the question of whether the disease spilled over naturally from animals to humans, or was the result of a lab accident, is viewed as vital to averting the next pandemic and saving millions of lives.

The first paper analyzed the geographic pattern of Covid cases in the outbreak's first month, December 2019, showing the first cases were tightly clustered around the Huanan Market. 

The second examined genomic data from the earliest cases to study the virus' early evolution, concluding it was unlikely the coronavirus circulated widely in humans prior to November 2019.

Both were previously posted as "preprints" but have now been vetted by scientific peer review and appear in a prestigious journal.

Michael Worobey of the University of Arizona, who co-authored both papers, had previously called on the scientific community in a letter to be more open to the idea that the virus was the result of a lab leak.

But the findings moved him "to the point where now I also think it's just not plausible that this virus was introduced any other way than through the wildlife trade at the Wuhan market," he told reporters on a call about the findings.

Though previous investigation had centered on the live animal market, researchers wanted more evidence to determine it was really the progenitor of the outbreak, as opposed to an amplifier.

This required neighborhood-level study within Wuhan to be more certain the virus was "zoonotic" -- that it jumped from animals to people.

The first study's team used mapping tools to determine the location of most of the first 174 cases identified by the World Health Organization, finding 155 of them were in Wuhan.

Further, these cases clustered tightly around the market -- and some early patients with no recent history of visiting the market lived very close to it.

Mammals now known to be infectable with the virus -- including red foxes, hog badgers and raccoon dogs, were all sold live in the market, the team showed.

- Two introductions to humans -

The study authors also tied positive samples from patients in early 2020 to the western portion of the market, which sold live or freshly butchered animals in late 2019.

The tightly confined early cases contrasted with how it radiated throughout the rest of the city by January and February, which the researchers confirmed by drilling into social media check-in data from the Weibo app.

"This tells us the virus was not circulating cryptically," Worobey said in a statement. "It really originated at that market and spread out from there."

The second study focused on resolving an apparent discrepancy in the virus' early evolution.

Two lineages, A and B, marked the early pandemic. 

But while A was closer to the virus found in bats, suggesting the coronavirus in humans came from this source and that A gave rise to B, it was B that was found to be far more present around the market.

The researchers used a technique called "molecular clock analysis," which relies on the rate at which genetic mutations occur over time to reconstruct a timeline of evolution -- and found it unlikely that A gave rise to B.

"Otherwise, lineage A would have had to have been evolving in slow motion compared to the lineage B virus, which just doesn't make biological sense," said Worobey.

Instead, the probable scenario was that both jumped from animals at the market to humans on separate occasions, in November and December 2019. The researchers concluded it was unlikely that there was human circulation prior to November 2019.

Under this scenario, there were probably other animal-to-human transmissions at the market that failed to manifest as Covid cases.

"Have we disproven the lab leak theory? No, we have not. Will we ever be able to know? No," said co-author Kristian Anderson of The Scripps Research Institute.

"But I think what's really important here is that there are possible scenarios and they're plausible scenarios and it's really important to understand that possible does not mean equally likely."

With inputs from AFP.