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How bad is Omicron? What are the scientists’ findings so far?

A mere seven days have passed since scientists from Botswana as well as South Africa alerted the world to a rapidly spreading SARS-CoV-2 type now referred to by the name Omicron. Researchers from all over the world are trying to comprehend the risk of the Omicron variant, which has been recognized by more than 20 nations posing to the world. However, it could take months to develop a complete image of Omicron and understand its severity and transmission as well as its ability to avoid vaccinations and create the spread of infection.

“Wherever I go, everyone says: tell us more about Omicron,” says Senjuti Saha, a molecular microbiologist who is also the director of the Child Health Research Foundation in Dhaka, Bangladesh. “There is so little understanding of what’s going on, and that’s true, even for scientists.”

Nature brings together the information scientists have discovered about the Omicron version.

How rapid is Omicron growing?

Omicron’s rapid growth within South Africa is what worries scientists the most since it indicates that the variant may trigger a surge in COVID-19 cases in other countries. On the 1st of December, South Africa recorded 8,561 cases which was up from the reported 3,402 cases on the 26th of November and several hundred cases per day during mid-November. The majority of the growth happening within Gauteng Province, home to Johannesburg.

Epidemiologists assess the growth of an epidemic by using the term R which is the number of cases created from each infectious disease. In the latter part of November South Africa’s National Institute for Communicable Diseases (NICD) in Johannesburg discovered the rate of growth was higher than 2 . Gauteng. This level of growth was first observed during the initial days of the pandemic Richard Lessels, an infectious-disease medical doctor at KwaZulu Natal University in Durban, South Africa, announced at a briefing for the press the week before.

Gauteng’s Gauteng’s value was lower than 1 in September which was the time during a time where Delta was the most common variant and cases were declining which suggests that Omicron is able to be more prevalent and affect many greater numbers of people than Delta is said to be. Tom Wenseleers, an evolutionary biologist at the Catholic University of Leuven in Belgium. Based on the increasing number of COVID-19-related cases and sequence data, Wenseleers estimates that Omicron could infect anywhere from three to six times more people than Delta in the same period of time. “That’s a huge advantage for the virus — but not for us,” Wenseleers says.

Researchers will monitor the way Omicron expands across other regions of South Africa and globally to be able to better understand the possibility of transmission, says Christian Althaus, a computational epidemiologist at the University of Bern, Switzerland. A greater focus on monitoring of South Africa could cause researchers to underestimate the speed of growth of Omicron. However, if this pattern were to be similar elsewhere, this could be strong proof that Omicron has a distinct advantage in transmission as per Althaus. “If it isn’t the case for instance, within European countries, that means that things are more complicated and heavily depend on the environment of immunology. We’ll have to be patient.”

Whole genome sequencing is not required to verify Omicron cases, certain PCR tests may reveal an indication of the variant which differentiates Omicron from Delta. Based on this evidence there are indications that cases, despite being small in numbers and increasing within The United Kingdom. “That’s certainly not what we want to see right now and suggests that Omicron could indeed also have a transmission advantage in the UK,” Althaus says.

Can Omicron overpower immunity to vaccinations or infections?

The rapid rise of the virus within South Africa hints that it may be able to escape immunity. About one-quarter of South Africans are fully vaccinated which suggests that a substantial portion people were infected by SARS-CoV-2 before the earlier outbreaks According to Wenseleers in light of the increase in mortality rates since the beginning of the epidemic.

In this regard the success of Omicron in southern Africa could be due in part because of its ability to infect those recovering of COVID-19 caused Delta and its variants, and also those who have been vaccinated. A preprint dated 2 December 1 by researchers at the NICD found that infections within South Africa have increased as Omicron has expanded. “Unfortunately, this is the perfect environment for immune-escape variants to develop,” Althaus says. Althaus.

The degree to which the variant is spread in other areas could be influenced by factors like vaccinations and the previous rate of infection as per Aris Katzourakis who studies viral development in the University of Oxford, UK. “If you throw it into the mix in a highly vaccinated population that has given up on other control measures, it might have the edge there.”

Researchers want to assess the ability of Omicron to avoid immune responses and the defense they offer. A group that is headed by Penny Moore, a virologist at the NICD and the University of the Witwatersrand in Johannesburg is studying the effectiveness of neutralizing, or anti-virus, antibodies that are that are triggered by prior infection or vaccinations to block Omicron to infect cells. To examine this in the laboratory the team is creating pseudovirus particles — an engineered form of HIV that utilizes the spike protein for infected cells that are similar to Omicron which has up to 32 modifications to spike.

Another team from South Africa is led by the virologist Alex Sigal at the Africa Health Research Institute in Durban which is also conducting tests for antibodies that neutralize viruses with infectious SARS-CoV-2 particles. The team is led by Pei-Yong Chi, an virologist at the University of Texas Medical Branch in Galveston who is working with the manufacturers of the Pfizer BioNTech vaccine to see how it holds against Omicron. “I was really very concerned when I saw the constellation of mutations in the spike,” Shi declares. “We just have to wait for the results.”

The previous studies of Omicron’s spike mutations — specifically on the part that identifies receptors on human cells suggests that the mutation could reduce the effectiveness in neutralizing antibody. In the October 2021 Nature paper 2 2, a group headed by Paul Bieniasz, a virologist at Rockefeller University in New York City developed an extremely mutated form of spike — which is the absence of any virus that could cause COVID-19 that has numerous mutations that are shared with Omicron. The “polymutant” spike was completely insensitive to neutralizing antibodies from the majority of people they examined, who had received two doses an mRNA vaccine , or had were cured of COVID-19. The Omicron vaccine is expected to be a major success. Omicron, “we expect there to be a significant hit” According to the report, Bieniasz.

How do vaccines perform against Omicron?

If Omicron can evade neutralizing antibodies, that doesn’t mean that the immune responses that are triggered through vaccination or previous infection are able to offer none protection to the variant. Research on the immune system suggests that low quantities of neutralizing antigens can help protect individuals from the severe form of COVID-19. Miles Davenport, an immunologist at the University of New South Wales in Sydney, Australia.

Other parts that comprise the immune system including T cells, could have less impact by the mutations in Omicron than antibody responses. Researchers from South Africa plan to measure the activities of T cells and an additional immune player , known as natural killer cells. They could be particularly important in preventing severe COVID-19 according to Shabir Madhi Vaccinologist from the University of the Witwatersrand.

Madhi, who has been the director of COVID-19 trials for vaccines within South Africa, is also part of the efforts to conduct studies on the epidemiology of the effectiveness of vaccines against Omicron. There are reports of outbreaks caused by all three vaccines which were given throughout South Africa — Johnson & Johnson Pfizer BioNTech, Pfizer and Oxford-AstraZeneca. However, Madhi states that researchers will seek to determine the degree in protection from Omicron given by vaccines and also by prior infections.

He is of the opinion that the findings will be similar to how the AstraZeneca Oxford vaccine performed in the past in the fight against Beta variant which is an immune-evading variant. It was first discovered within South Africa in late 2020. A study conducted by Madhi discovered that the vaccine provided only marginal protection against moderate and mild diseases, whereas a real-world study in Canada demonstrated more than 80% protection from hospitalization.

If Omicron is similarly affected, Madhi says, “we’re likely to see a flurry of cases. We’ll see a lot of infections that are breakthrough, many reinfections. There will be a reversal of the rate of cases in the community as compared to the rate of hospitalization”. Early reports suggest that the majority of cases of breakthrough infections caused by Omicron have been minor and not serious, according to Madhi. “For me, that is a positive signal.”

Will current boosters improve protection against Omicron?

The danger of Omicron has led some wealthy nations, like that of the United Kingdom, to accelerate and extend the introduction of COVID booster doses of vaccine. It’s still unclear what the effectiveness of the doses are against this type of.

Third doses supercharge neutralizing-antibody levels, and it’s likely that this will provide a bulwark against Omicron’s ability to evade these antibodies, says Bieniasz. The research of his team in the study of the mutant spike showed that those who recovered from COVID 19 months prior to receiving their jabs were able of stopping mutations in the spike. According to Bieniasz, these results suggest that those who have repeatedly exposed to the SARS-CoV-2 spike protein, whether via infection or a booster dose have “quite likely to have neutralizing activity against Omicron”.

Is Omicron a cause of milder or more severe illness than other versions?

Initial reports linked Omicron with mild illness and raised expectations that it could be less severe than its predecessors. But these reports typically founded on anecdotes and a few fragments of data could be deceiving, warns Muge Cevik. She is an infectious disease expert from the University of St Andrews, UK. “Everyone is trying to find some data that could guide us,” she declares. “But it’s very difficult at the moment.”

The biggest challenge in determining the severity of a particular variant is to deal with the numerous factors that may influence the course of the disease, especially when the outbreaks are regionally localized. For instance reports of mild diseases caused by Omicron infections within South Africa could reflect the situation that the country is home to an incredibly young population, a lot of whom have been infected with SARS.

In the beginning in the Delta outbreak, there were reports that the variant caused more serious illnesses among children than other variants -this was a connection that disintegrated when more data were collected, Cevik says.

Researchers will search for evidence of Omicron diseases in different countries. The geographical spread, as well as the larger sample size as the number of cases increases and cases increase, will give researchers an understanding of how generalized the initial reports of mild diseases could be. Researchers will ultimately want to conduct studies that are controlled by case where 2 groups of people are linked on the basis of key factors such as age as well as vaccination status and health issues. Both groups’ data must be simultaneously due to the fact that the frequency of hospitalizations could be affected by the capacity of hospitals overall in a specific region.

Researchers will have to be aware of the extent of poverty. The rapidly spreading variant could reach vulnerable populations faster, Cevik says, by the nature of their work or living environment. They also tend to experience more severe symptoms.

It will require time. “I think the severity question will be one of the last bits that we’ll be able to untangle,” she states. “That’s how it happened with Delta.”

Where is Omicron spread ? And how do researchers track it?

More countries are finding this Omicron variant, however the ability to quickly identify virus from positive COVID-19 tests is concentrated in the wealthy nations which means that the early data regarding the spread of Omicron’s virus are likely to be biased.

The surveillance efforts in Brazil as well as other countries are making use of a distinct result from one particular PCR test that can enable them to identify the possibility of Omicron cases to be sequenced as suggested by the virologist Renato Santana of the Federal University of Minas Gerais in Brazil. The test is based on segments of three genes that are viral and one of them is the gene that codes for the protein spike. Variations in the Omicron spike gene block its detection during the test, which means that the samples containing this variant are positive only for two genes.

However, not every person utilizes the test, and it may take some time before the spread of Omicron is completely identified. Despite guidelines encouraging nations to test the 5% of their blood samples that are positive for SARS-CoV-2, a small percentage of them are able to afford the according to computer-generated expert in virology Anderson Brito at the All for Health Institute in Sao Paulo, Brazil. Additionally, Brito fears about the travel restrictions enacted by certain nations towards South Africa, and other southern African countries, following the Omicron discovery could deter governments from sharing data on genomic surveillance. “We are punishing those who did a good job,” Brito states.

In Bangladesh where it is estimated that the sequences comprise 0.2 percent of positive coronavirus samples researchers are eager to increase the number of sequences, they use to monitor Omicron and other new variants Saha says. Saha. However, resources are scarce. Bangladesh has been recovering after a major dengue epidemic, she says. “In the global south, we are all worried about COVID, but let’s not forget our endemic diseases,” Saha declares. “We can only do so many.”



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