In late 2020, the network detected a new virus lineage, 501Y.V2, which later became known as the beta version. Now a new SARS-CoV-2 variant has been identified, known as B.1.1.1.529.
What is the science behind the discovery?
Different types of hunting require a concerted effort. South Africa and the UK were the first major countries to implement nationwide genomic surveillance efforts for SARS-CoV-2 in early April 2020.
Variant hunting, as exciting as it sounds, is done through whole genome sequencing of samples that have tested positive for the virus.
The process involved checking each sequence received for differences, which we know is circulating in South Africa and the world.
When we see many differences, it immediately raises a red flag and we investigate further to confirm what we have seen. Fortunately South Africa is well prepared for this.
This is thanks to the National Health Laboratory Service, (NGS-SA) the central repository of public sector laboratory results, good links to private laboratories, the Western Cape Province’s Provincial Health Data Center and state-of-the-art. Modeling expertise.
In addition, there are several laboratories in South Africa that can grow and study the actual virus and find out how well the antibodies formed in response to vaccination or previous infection are able to neutralize the new virus. This data will allow us to characterize the new virus.
The beta version spread more efficiently between people than the “wild type” or “ancestral” SARS-CoV-2 and caused South Africa’s second wave of pandemics. Therefore it was classified as a type of anxiety.
During 2021, another variant of the concern called Delta spread to much of the world, including South Africa, where it caused a third pandemic wave.
Recently, routine sequencing by Network for Genomics Surveillance member laboratories led to the detection of a new virus lineage in South Africa, called B.1.1.
Seventy samples collected in Gauteng province in mid-November 2021 had the virus.
Smaller numbers have also been reported from neighboring Botswana and Hong Kong. The Hong Kong case is reportedly a traveler from South Africa.
The World Health Organization on Friday classified B.1.1.529 as a variant of concern and named it Omicron under its Greek-letter system.
Why is South Africa posing as a concern?
We don’t know for sure. It certainly appears to be much more than the result of concerted efforts to monitor circulating viruses.
One theory is that people with highly compromised immune systems, and who experience prolonged active infections because they cannot clear the virus, may be the source of new viral variants.
The assumption is that there is some degree of “immune pressure” (meaning an immune response that is not strong enough to eliminate the virus yet exerts some degree of selective pressure that “forces” the virus to grow). It creates the conditions for the emergence of new forms.
Despite an advanced anti-retroviral treatment program for people living with HIV, many individuals in South Africa have HIV disease and are not on effective treatment.
Several clinical cases have been investigated that support this hypothesis, but much remains to be learned.
Why is this version worrying?
The short answer is, we don’t know. Long answer is, b.1.1.1.529 has some changes that are related.
They have not been observed in this combination before, and over 30 mutations occur in the spike protein alone.
This is important, as the spike protein itself makes up most of the vaccines.
We can also say that the genetic profile of B.1.1.1.529 is very different from that of other circulating forms of interest and anxiety. It does not appear to be “Delta’s daughter” or “Beta’s grandson”, but rather represents a new lineage of SARS-CoV-2.
Some of its genetic changes are known from other variants and we know that they may affect transmission ability or allow immune evasion, but many are new and have not yet been studied.
While we can make some predictions, we are still studying how much the mutations will affect its behavior.
We want to know about infection, disease severity, and the ability of the virus to “escape” the immune response in people who have been vaccinated or cured. We are studying this in two ways.
First, careful epidemiological studies seek to ascertain whether the new lineage shows changes in transmission potential, the ability to vaccinate or infect already infected individuals, and so on.
At the same time, laboratory studies examine the properties of the virus.
Its viral growth characteristics are compared with those of other virus variants and it is determined how well the virus can be neutralized by antibodies found in the blood of vaccinated or cured individuals.
Finally, the full significance of the genetic changes observed in B.1.1.529 will become clearer when the results of all these different types of studies are considered.
It is a complex, demanding and costly undertaking, which will last for months, but is indispensable to better understand the virus and devise the best strategies to combat it.
Do early signs point to a different type of symptom or a more serious illness?
There is no evidence of any clinical difference yet. It is to be known that cases of B.1.1529 infection have increased rapidly in Gauteng, where the country’s fourth epidemic wave seems to be starting.
This suggests easy transmission despite the background of very easy non-pharmaceutical interventions and low number of cases.
So we can’t really tell yet whether the already prevalent version of the B.1.1.529 concern transmits more efficiently than Delta.
COVID-19 is more likely to manifest as a serious, often life-threatening illness in the elderly and chronically ill.
But the population groups most often first exposed to a new virus are young, mobile and generally healthy people.
If B.1.1529 spreads further, it will take some time to assess the severity of the disease before its impact.
Fortunately, it seems that all the diagnostic tests tested so far have been able to identify the new virus.
Even better, it appears that some widely used commercial assays show a distinctive pattern: two of the three target genome sequences are positive but the third is not.
It’s as if the new version consistently ticks two out of three boxes in the current test. This can serve as a marker for B.1.1.1.529, which means we can quickly estimate the proportion of positive cases due to B.1.1.1.529 infections per day and per area.
This is very useful for monitoring the spread of the virus in near real time.
Are existing vaccines likely to protect against the new version?
Again, we don’t know. Known cases include individuals who were vaccinated.
However we have learned that the immune protection provided by vaccination diminishes over time and does not protect against infection as much, but rather from serious illness and death.
One of the epidemiological analyzes is to see how many people have been infected with B.1.1.
The possibility that B.1.1529 might survive an immune response is disappointing.
The hopeful expectation is that the high seroprevalence rate, which many studies have shown, will confer a degree of “natural immunity”, at least for the time being.
Ultimately, what is known so far about b.1.1.1.529 highlights that universal immunization against severe COVID-19 is still our best bet and, as with non-pharmaceutical interventions, there will be more to come. will go a long way towards helping the healthcare system cope during the Wicked Wave. ,
This story has been published without modification in text from a wire agency feed. Only the title has been changed.
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