Friday, February 3rd, 2023 08:28:51

Understanding another Covid-19 surge

Updated: December 28, 2022 1:45 pm

The COVID-19 pandemic has not left us, still lurking in the darkness in India. In China, it has created massive devastation, millions lives stand to perish now. The global pandemic of coronavirus caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identified in an outbreak in the Chinese city of Wuhan in December 2019. Attempts to contain it there failed, allowing the virus to spread to other areas of Asia and later worldwide. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern on 30 January 2020, and a pandemic on 11 March 2020. As of 27 December 2022, the pandemic had caused more than 657 million cases and 6.67 million confirmed deaths, making it one of the deadliest in history.

Now, the new sub-variant of the highly infectious Omicron variant of coronavirus is driving the current surge of Covid-19 infections in China. China is currently witnessing an unprecedented Covid-19 surge and Chinese healthcare system is overwhelmed. Shortages of medicines have also been reported amid suggestions that Chinese authorities are covering up the true extend of outbreaks. The China’s Covid-19 surge is being driven by BF.7 Omicron sub-variant. The surge follows the relaxation of China’s ‘Zero Covid’ policy after a wave of intense nationwide protests. Projections show that China’s Covid-19 situation is expected to get worse through the winters.

The BF.7 Omicron sub-variant’s full name is BA.5.2.1.7. SARS-CoV-2, the virus that causes Covid-19 disease, has evolved since it first emerged in 2019 just like any other virus. As SARS-CoV-2 evolved, it acquired a number of mutations which led to a number of variants, such as Alpha, Delta, and Omicron. These variants further went through mutations to form branches of themselves, leading to sub-variants.

Every variant has a number of sub-variants. The deadly Delta variant behind India’s second wave has up to 200 sub-variants.

What we know of BF.7 Omicron sub-variant in China?

It’s known that the BF.7 Omicron sub-variant is driving the current Covid-19 surge in China.

Though the virus is primarily driving the surge in China, it has been found in the United States, Denmark, Germany, France, and India.

Chinese experts have said that it is much more transmissible than earlier coronavirus strains. It’s reportedly the main strain in Beijing which is reporting a surge of infections.

The BF.7 Omicron sub-variants has the “strongest infection ability” so far poses risk of “hidden spread”, according to Beijing-based expert at Xiaotangshan Hospital. Li Tongzeng. Compared with the BA.1, BA.2 and BA.5 variants detected previously, Omicron BF.7 has more immune escape capability, a shorter incubation period and faster transmission rate.

Tongaeng said the reproduction number (R0) of the BF.7 Omicron sub-variant is 10 whereas it was 5-6 for Delta variant.

R0 is a number that measures how transmissible an infectious disease is. The higher the number, the more infectious it is.

R0 tells you the average number of people who will contract a contagious disease from one person with that disease.For example, if a disease has an R0 of 18, a person who has the disease will transmit it to an average of 18 other people.

Though BF.7 has very high transmissibility, its symptoms are similar to earlier Omicron sub-variants. These are:

Fever

Cough

Sore throat

Vomiting

Diarrhea, etc


What makes BF.7 different and concerning?

As the virus mutates over time, some of the mutations that the resultant variants and sub-variants acquire enable them to work better. For example, the Delta variant is deadlier and Omicron variant is highly transmissible because of their unique mutations.

The new subvariant has a change in the spike protein —a feature that allows it to enter cells— seen in other Omicron strains making headway. It also has a change in the nucleotide sequence —sometimes referred to as the blueprint of an organism— that could cause it to behave differently than other subvariants. These mutations give BF.7 some immune-evasive abilities, which means it can escape immunity from vaccine or previous infection, according to microbiology expert Manal Mohammed of University of Westminster.

A recent study examined the neutralisation of BF.7 in sera (a component of blood that should contain antibodies) from triple-vaccinated healthcare workers, as well as patients infected during the omicron BA.1 and BA.5 waves of the pandemic. BF.7 was resistant to neutralisation, driven partly by the R346T mutation. Though BF.7 causes concerns, it is not having an effect similar to China in the United States or United Kingdom. Citing recent data, she notes that BF.7 amounts to just 5.7 per cent cases in USA and 7 per cent in UK.

The BF.7 severe impact in China could be because of lower vaccination or lower immunity among people, either from lower vaccination rates or fewer previous infections. BF.7’s high R0 might be due in part to a low level of immunity in the Chinese population from previous infection, and possibly vaccination too. We should, of course, be cautious about the data from China as it’s based on reports, not peer-reviewed evidence yet.

China has rejected foreign vaccines and has relied on Chinese vaccines known to be less effective. This has been flagged as possible reason for the current surge in infections.

The lower efficacy of the two key Chinese-made vaccines became a concern early in the pandemic, when global health experts suggested adding a third shot to protect older people. Vaccines from two companies, Sinovac and Sinopharm, are based on an inactivated form of the virus. The mRNA vaccines, by contrast, instruct the body’s own cells to build a replica of a key coronavirus protein to trigger an immune response.

What is alaraming! Sorry, for being a doomsday preacher. Up to 2 million can die in China: Projections

Projections of infections and deaths in China say that 1.3-2.1 million people could die in China in near future from Covid-19. These are the projections by The Economist and The Lancet.

The Economist reports around 1.5 million Chinese could die based on its model that calculates the trajectory of China’s outbreak under different scenarios based on estimates of the rates at which people become infected, get sick, recover or die – referred to as the SEIR model, according to PTI.

It reports The Lancet’s report quoting a projection saying that somewhere between 1.3 and 2.1 million people could die from Covid-19 after China re-opens.

There are also signs that Chinese authorities are covering up the true extent of the Covid-19 outbreak.

Reuters reported that dozens of funeral took place in Beijing with funeral staff in hazmat suits despite China reporting zero Covid-19 deaths.

“At a crematorium in Beijing’s Tongzhou district, a Reuters witness saw a queue of about 40 hearses waiting to enter while the parking lot was full. Inside, family and friends, many wearing traditional white clothing and headbands of mourning, gathered around about 20 coffins awaiting cremation. Staff wore hazmat suits and smoke rose from five of the 15 furnaces,” reported Reuters.

It also reported that medicines are in shortage at places in China.

“The abrupt change of policy has caught a fragile health system unprepared and hospitals are scrambling for beds and blood, pharmacies for drugs, and authorities are racing to build special clinics,” reports Reuters about how Chinese healthcare system is being overwhelmed.

“There will certainly be more omicron subvariants developing in China in the coming days, weeks and months, but what the world must anticipate in order to recognize it early and take rapid action is a completely new variant of concern,” said Daniel Lucey, a fellow at the Infectious Diseases Society of America and professor at Dartmouth University’s Geisel School of Medicine. “It could be more contagious, more deadly, or evade drugs, vaccines and detection from existing diagnostics.”

The closest precedent to what could happen, Lucey says, is the experience with delta in India in late 2020 when millions of people were infected over a short period of time and the deadly strain raced around the globe. While it’s not inevitable, the world must protectively prepare for such an event so that vaccines, treatments and other necessary measures can be ready, he said.

 

Tracking

China is closely watching omicron subvariants circulating in the country, Xu Wenbo, director at the National Institute for Viral Disease Control and Prevention, said Dec. 20 at a briefing in Beijing. It has established a national Covid viral sequencing database, which will receive genetic sequences from three hospitals in every province each week to catch any emerging variants, he said.

There is little clarity now about infections and deaths in China, after the country largely abandoned its mass testing regime and narrowed the way it measures Covid mortality.

 

Diverging Paths

There are two paths the virus could take in China. Omicron and its hundreds of subvariants may sweep directly through, likely in several waves, leaving no room for other contenders – as it has in the rest of the world for all of 2022. Vaccination and infections will boost immunity until eventually antibodies in the population will help control serious disease.

 

“It might be that China catches up, and what comes out is more of what we have already seen,” said Stuart Turville, a virologist at the University of New South Wales’ Kirby Institute, who has conducted research showing that existing antibodies in some people bind even to emerging variants. “Our antibodies are mature enough to deal with them.”

 

The other possibility is that something else entirely develops, much like the way the original omicron emerged in southern Africa in late 2021. That could pose a novel threat for the world.

 

Omicron “came out of nowhere,” Turville said. “It made an evolutionary change in a way that’s different. If that’s the path, and it spreads more easily, there might be another parachuting event, where it takes a trajectory we don’t expect.”

Lagging Immunity

The fact that China doesn’t have a lot of previous exposure to the virus could work in its favor when it comes to the risk of new variants. In most of the world, the virus has been under severe pressure, forced to mutate like a contortionist to get around existing antibodies, Turville said. That may not be necessary in China

“It’s a different situation,” said Alex Sigal, a virologist at the Africa Health Research Institute in Durban. “It’s going through a population that doesn’t have a lot of immunity. Just because there are more infections doesn’t mean we’ll have nastier infections.”

 

On the other hand, it may give other new variants a chance to take off because there isn’t such a bar of immunity, Sigal said. That could be problematic if something worse emerges.

That is Turville’s primary concern.

“Maybe it will go down a different route because it’s not under pressure and there is more room to move,” he said. “It could be a seismic shift, something that’s completely different. It may be a low probability, but it’s a probability and we have to be ready for that. At the moment, it’s crystal ball gazing.”

 

Omicron doesn’t penetrate as deeply in the lower respiratory tract or do as much harm as some of the earlier strains. Its superpowers include its contagiousness and ability to evade existing immunity, a combination that slammed the door on other variants – including those that could have been more virulent.

 

Low Risk

Not everyone is concerned. Stephen Goldstein, an evolutionary virologist at the University of Utah, said the differences in the immunity landscape between China and the rest of the world makes it unlikely that the emerging omicron subvariants will have advantages over what is already circulating.

“With respect to new dangerous variants emerging from China, I’m not particularly concerned right now,” he said. “I don’t think the situation in China significantly affects the situation everywhere else,” he said. “Could something out of the blue emerge and cause problems? Maybe – but we can’t predict it and it isn’t what I expect,” he said.

While Covid science has become highly politicized in China, officials there also say the danger is remote, even as omicron continues to mutate.

To Catch a Killer

Yet the global pullback from sequencing Covid could mean a new, possibly dangerous variant evades detection until it’s spreading widely.

“This will bite us,” said Maria Van Kerkhove, the World Health Organization’s Covid-19 technical lead. “We need to have some eyes around the world on this,” she said.

The virus “hasn’t settled down into a predictable pattern,” the WHO scientist said. “We know that it will continue to evolve. And this notion that it will only become more mild is false. It could – and we hope so – but that’s not a guarantee.”

 

China’s Covid Tsunami Could Spark a Dangerous New Variant That Infects the World

The tsunami of Covid-19 that’s taking hold across China is spurring concern that a dangerous new virus variant could emerge for the first time in more than a year, just as genetic sequencing to catch such a threat is dwindling.

The situation in China is unique because of the path it’s followed throughout the pandemic. While almost every other part of the world has battled infections and embraced vaccinations with potent mRNA shots to varying degrees, China largely sidestepped both. The result is a population with low levels of immunity facing a wave of disease caused by the most contagious strain of the virus yet to circulate.

The expected surge of infections and deaths are taking hold in China within a black box since the government is no longer releasing detailed Covid data. The spread has medical experts and political leaders in the US and elsewhere worried about another round of disease caused by the mutating virus. Meanwhile, the number of cases sequenced globally each month to find those changes has plunged.

Comments are closed here.