Experts say that the Omicron variant could dash any lingering hopes of populations reaching herd immunity against COVID-19, after a preprint study from South Africa suggests the highly-mutated strain is more capable of reinfecting people than previous strains.

South African researchers have found that Omicron is 2.4 times more likely to reinfect someone who has already had COVID-19 when compared to other studied strains.

The study found a recent spike in reinfections, which is likely attributable to Omicron, since researchers found no increased risk of reinfection during the waves of cases brought about by the Beta and Delta variants.

The study, which was released on preprint server MedRxiv by a cohort of South African labs led by Stellenbosch University, and is yet to be peer reviewed, indicates that Omicron may be adept at evading natural immunity built up by previous exposure to other variants.

"Analysis of routine surveillance data from South Africa suggests that, in contrast to Beta and Delta, the Omicron variant of SARS-CoV-2 demonstrates substantial population-level evidence for evasion of immunity from prior infection," said authors of the study.

Simon Clarke, who is associate professor in cellular microbiology at the University of Reading in the United Kingdom, said that Omicron has "blown a big hole in the controversial argument" that the infection should simply be allowed to spread in an attempt to create immunity.

"Herd immunity now seems like nothing more than a pipe dream," Clarke said.

While more data is needed, experts said that if Omicron is capable of evading natural immunity, there is a chance that current vaccines will prove less effective against the new variant.

"If it can escape natural immunity it is also likely to have substantial escape potential for vaccine-induced immunity," said Paul Hunter, a professor in medicine at the University of East Anglia.

There is currently no indication as to how Omicron is able to better escape natural immunity than previous variants, though Clarke says this is likely to do with the number of mutations on the spike protein.

Omicron has 32 mutations on the spike protein, which is the area of the virus targeted by both the body's immune system and by vaccines. By comparison, the Delta variant has 10 spike protein mutations. Put simply, a highly-mutated spike protein may be harder for the body — or a treatment — to recognize.

Michael Head, who is senior research fellow in global health at the University of Southampton, said that there is a chance that Omicron is better at evading natural immunity than it is at eluding vaccine protection.

"The immune response from vaccination is much stronger when compared with infection-acquired immunity," Head said. "Whilst there is likely to be some impact, it is likely vaccines will still provide some level of protection."

The study did not include data on the severity of illness among the reinfected, which is needed in order to forecast how reinfections might impact hospitalization rates and deaths.

Zheng Jingtai was a well-dressed partner at a law firm in Quanzhou, Fujian province, until two years ago. Then, he quit his job to take a break, and along with his wife, Qing Ying, embarked on a journey that took them from the eastern province to the country's northwest and back.

Their return journey to Quanzhou from the Xinjiang Uygur autonomous region was with the help of horses.

The experience won Zheng about 170,000 followers online after he did live broadcasting to share their journey from time to time.

"I had to give up my income and hand my work over to my business partners half a year in advance to ensure the best interests of my clients," recalls Zheng, 39. "I can always make money, but I can live only once, so I had to listen to my inner voice."

For him, it was a choice not so much out of a whim as it was about a search for the meaning of life.

In early 2020, Zheng had then been married for just two years and had about 400,000 yuan ($62,600) in family savings. The couple lived in a rented apartment in downtown Quanzhou. Zheng painted a rosy picture for Qing about the trip to persuade her to go along.

"I told her how romantic it would be to travel across the country, playing with horses and enjoying the sea and blossoms," he says.

He convinced his in-laws about how he had things all planned out for later. Zheng's partners at the law firm were supportive of his decision and would have him back after the trip, he says.

Getting the nod from his family, Zheng got down to preparations. He bought items such as a tent, sleeping bags, solar panels and a satellite phone. The two then left their 1-year-old daughter in the care of their parents and hit the road in March 2020. They first flew to Yining, Xinjiang.

"We were filled with excitement about the unknown," he recalls.

They went straight to local farmers and bought two tough horses for 50,000 yuan. Since there are many uninhabited areas in Xinjiang, some of which might have taken them days to cover, Zheng designed a wagon to carry supplies. "The first one was too light and could easily bump off the road."

So he used the steel and chassis of a motor vehicle to build a wagon that weighed about 200 kilograms and attached it to the horses. Yet, it didn't take long before reality diluted their enthusiasm.

"The horses had trouble climbing steep slopes, and we had to empty the wagon and then upload all over again in such places," Zheng says.

Moments of desperation also sneaked up when a wheel of the wagon broke in the middle of nowhere. "It was all exhausting, in terms of energy and money."

Yet, the stunning natural scenery in such places kept them going.

"At dusk, there were clouds all over the sky, which changed from red to purple as the sun shone on them, much like the nebula," Zheng says, poetically.

Such images "move you to tears and make you feel small in the big universe", he adds.

A white winter in Beijing is nothing new, the city is frequently enveloped in snow over the colder months, but the earlier than usual snowfall last weekend, only 7 days later than the earliest on record, led to a unique coalescence of the seasons and a contrast of colours, with the rich autumn palettes prevalent across the city partially shrouded in white.

Famous locales were blanketed with a layer of snow and visitors, including myself, flocked to landmarks across the city to take in these familiar sights with a new perspective. Camera in hand and braving the cold, I headed off to two of my favourite locations.

My first stop was Jingshan Park, constructed in the Ming Dynasty (1368 - 1644) the manmade hill and surrounding park offer remarkable views of the ForbiddenCity, the Beijing CentralAxis and wider city as a whole.

After a lengthy queue to get into the park, and an even greater one to reach the peak of Jingshan, or Prospect Hill, itself, I battled my way through the crowds to take in the landscape around me. It is a view I have seen innumerable times and remains one of my favourite in the city, and the coating of snow, contrasting with the vibrant colours of the autumn leaves and ancient structures only added to its elegance and mystery.

Next up was Xiangshan park, or FragrantHills, which dates back to the Jin Dynasty (1115 - 1234).

The park is most famous for its gardens that spring to life in the autumn, with people travelling from all over China to take in the natural scenery of the tree-covered hillsides transforming from their rich summery greens into striking yellows and reds like a blanket of fire, however the weekends abnormal weather had partially extinguished these fiery vistas.

The park had become a strange amalgam of two vastly different seasons, icicles hung menacingly from the eaves of temple roofs, while the golden leaves of the pungent gingko trees sprung out of the snow coating the ground.

Whatever the reason for this early snowfall, the contrasting colours of these two seasons colliding highlighted the natural and manmade beauty of the city, the results of which led to an incredible fusion that I won’t soon forget.