Does the first coronavirus that triggered the pandemic still exist? – Orange County Register

Of course, you know alpha, beta, and delta (similar to Prince, the virus formerly known as B.1.617.2).

But do you know Delta AY? What about epsilon, gamma, iota, lambda, mu and theta? These variants of SARS-CoV-2 have all been recorded in Southern California, and dozens of other versions of the virus are circulating around the world, battling for world domination like the tiny Dr. Evils in an Austin Powers movie. .

So what happened to the “original” virus? The very first who jumped from bats or labs – or anywhere – in human beings who were immunologically powerless against her, ultimately leading to the deaths of nearly 5 million people and crippling global economies?

Gone are the “way of the dinosaurs, at least in humans,” said Dr. George Rutherford, professor of epidemiology and biostatistics at UC San Francisco.

“He was moved. Cut out by newer, more competitive strains, ”said Andrew Noymer, epidemiologist and demographer at UC Irvine who studies infectious diseases.

No one can say for 100% certainty that it’s gone, however, Noymer said. And Rutherford adds this caveat:

“God knows what’s going on with bats.”

Welcome to this user-friendly tutorial on viral mutation and why your life may depend on it.

The SARS-CoV-2 that surfaced in Wuhan, China in 2019 was probably not the original, say the researchers. And the version that swept across the United States in the fall of 2020 was already a mutation of the Wuhan version. And the one that swept across the United States this summer was different again.

Scientists have recorded dozens of virus versions that causes COVID-19 across the world, and through genetic sequencing, they can identify those circulating where. Sometimes these genetic changes have little impact. Sometimes they make the virus much more effective at infecting humans or evading treatment, and therefore more dangerous.

The United States Centers for Disease Control and Prevention lists only highly contagious delta B.1.617.2 and AY lines as “worrisome variants”Here in the United States, while the World Health Organization also includes alpha, beta and gamma on its list of “worrying variants”.

Mutants to watch out for? WHO keeps an eye on lambda and mu.

Once upon a time viral

Scientists saw it coming.

Michael Buchmeier, an infectious disease researcher at the UCI who has studied coronaviruses for decades, takes us back twenty years to the original strain that started the SARS-1 epidemic in 2002-03.

At the time, only 12 other animal or human coronaviruses were known.

SARS-1 likely arose when two or more strains of bat coronavirus combined and jumped on palm civets, a masked animal that resembles a raccoon and is widely sold in animal markets. alive all over Asia, he said. There, the virus was amplified and adapted, and eventually infected humans. It has spread widely in China, Hong Kong, Taiwan and Canada due to travel.

The death rate was 10%; for those over 50, it was close to 50%.

However, there is one key difference between SARS-1 and SARS-2: SARS-1 infections were essentially always symptomatic, making it much easier to spot and isolate outbreaks. SARS-2 can be transmitted by people without symptoms, making it much more difficult to stop.

So where is this virus now?

“SARS-1 as a single pathogen appears to be ‘extinct’ in nature, but the conditions that produced it still exist,” Buchmeier said.

“That is, the presence of coronavirus present in wild bats, especially in horseshoe bats common throughout South Asia and China, and the breeding of hosts suitable enhancers like civet, raccoon dog, and now pangolin and possibly others able to adapt the virus to infect humans more easily.

Hundreds of viruses have been isolated from bats in Asia and around the world, many of which are coronaviruses that can recombine into dangerous pathogens, he said.

A paper in Clinical microbiology journals, published in 2007, issued a warning: “Coronaviruses are well known to undergo genetic recombination, which can lead to new genotypes and epidemics. The presence of a large reservoir of SARS-CoV-like virus in horseshoe bats, as well as the culture of eating exotic mammals in southern China, is a time bomb. The possibility of the re-emergence of SARS and other new viruses from animals or laboratories and therefore the need for preparation should not be ignored. “

In 2015, another paper, in the journal Nature, warned of “a potential risk of re-emergence of SARS-CoV from viruses currently circulating in bat populations”.

And, therefore, here we are. The precise origin of the virus that triggered the COVID-19 pandemic is still an official mystery, and may still be. In addition to the widely held bat / wet market theory, it is suspected that the virus may have leaked from a laboratory in Wuhan. WHO appointed new 25-member group Scientific Advisory Group on the Origins of New Pathogens, with scientists from all over the world, to try to understand this part.

The following ?

Genetic flexibility is the superpower of an RNA virus.

“This flexibility results in the production of a swarm of related viral ‘offspring’ in each round of replication, allowing the virus to select the genetic makeup best suited to a given host in the form of the variant viruses that we currently know.” . Buchmeier said in a recent explainer.

“Mutations are always present in progeny viruses and can be selected if there is an advantage offered for replication in a new host species.”

The alpha variant, which was found in the UK last year, was much more contagious than the early versions. And the alpha gave birth to the beta, gamma and delta variants. Delta, as we know from summer surges, is about twice as contagious as alpha.

How did delta do this? It has adapted to produce up to 1,000 times more virus in the nasal passages and upper respiratory tract at the onset of infection, when people may not have symptoms.

This offers two distinct advantages, from a virus perspective: droplets from a person’s upper respiratory tract – during a sneeze, say – would spit out a lot more virus into the air to find new hosts; and the human immune response is not as robust in the upper respiratory tract as it is in the lower respiratory tract, Buchmeier said.

This combination leads to many asymptomatic carriers who then pass the infection on to others.

So far, the variants do not appear to have reduced the effectiveness of vaccines, but they strain the effectiveness of treatments.

The gamma, beta, kappa, mu and zeta variants may be moderately less sensitive to some antibody treatments, while iota is significantly less sensitive to some antibody treatments, according to California Department of Public Health.

Epsilon, on the other hand, appears to cause 20% more transmission, with drastically reduced effectiveness of some antibody treatments.

Changing nation

Each new infection is a new opportunity for the virus to mutate into something else. Maybe something less awkward. Maybe something more awkward.

“What worries me about the coming winter wave is not so much the variants, it is that we need more people vaccinated,” said Noymer of the UCI. “Seventy-five percent is not good enough to protect certain age groups.”

Vaccination does not prevent infection, but it is very protective against serious illness, hospitalization, and death, even with the highly contagious delta variant.

“The clear message is that as long as vaccination of populations remains incomplete and clearly effective social distancing and masking is not observed, we will most likely see more waves,” Buchmeier said.

Will SARS-CoV-2 mutate into something even more deadly? Crystal balls are cloudy, but many experts don’t expect that to happen. However, they expect it to remain circulating as part of the “human virome” – the total collection of viruses in and on the human body – for a very, very long time.

Viral variants will continue to appear, and some may be more able to spread.

But even if we do end up making our peace with this virus – as we did with the flu – threats loom. Buchmeier said the precursors of SARS-CoV-1 and SARS-CoV-2 remain in bats and could act as a reservoir for future cycles of human infection.