The new variant is likely to be far more permeable than Delta, but studies suggest it may be less severe.
Two years into the pandemic, the only thing we are sure about is the ever-changing, ever-changing nature of the Sars-CoV-2 virus that causes COVID-19. Since the start of the outbreak in December 2019, the virus has given rise to a variety of variants under the names of the Greek alphabet alpha, beta, gamma, delta and now, omicron.
Labeling the new variant as Omicron, the World Health Organization (WHO) classified it as “highly permeable” in November 2021. Since then, this variant has wreaked havoc in many countries, with their number of cases being recorded high.
Even as case numbers continue to rise around the world – the United States has recently averaged 800,000 new infections every day – health experts predict O’Micron’s death toll will be less than the devastation in previous waves. exclusively operated by Delta.
The new version of the coronavirus was first detected in South Africa in late November last year, after scientists said it was behind the spike in infections in the country. Like other types, some infected people show no symptoms, South African experts said at the time.
Soon after, WHO named the new version Omicron and classified it as “highly permeable”.
The variant has about 50 mutations that were not previously observed in combination, including more than 30 mutations on the spike protein that the coronavirus uses to attach to human cells. Vaccines in current use target the enhancer protein according to a Reuters report good. This means that the protection provided by the COVID-19 vaccine may be less effective on Omicron.
How transmissible is Omron?
One of the earliest studies on the transmittance of Omicron, conducted by researchers in the United Kingdom, revealed The new version was two to three times more likely to infect people than Delta, especially in a home setting.
Associate Professor of Epidemiology at Harvard’s T.H. Chan School of Public Health, Bill Hannage, said Omicron was expected to show a tendency for cluster transmission in large gatherings.
A more recent study conducted in France suggested that the omicron may be 105 percent more transmissible than the delta. The study, which analyzed more than 131,000 samples but has yet to be peer-reviewed, noted that even though the severity of omicrons is lower compared to deltas, the higher reproduction numbers — the number of people in a population that have a can be infected by a person. This means that French hospitals could see more activity, if not overloading – at any specific time.
Another factor that sets Omicron apart is the increased risk of reinfection. A study from Imperial College London showed that Omicrons were 5.4 times more likely to be reinfected than Delta.
In a recent press conference, WHO’s technical head on COVID-19, Maria Van Kerkhove, said that Omicron was “transmitting efficiently” and was being detected in all regions with good gene sequencing options.
Explaining why Omicron has caused a huge jump in case numbers, Kerkhov said the virus was able to more easily adhere to human cells because of its mutation, cause re-infection, and replicate in the upper respiratory tract. Which, he said, sets it apart from other types like Delta.
“This combination of factors allowed the virus to spread more easily. With Omicron, what we’re learning is that your risk of getting serious disease is lower than with Delta,” she said. However, the infectious diseases expert cautioned that the global health body is still seeing a surge in the number of people requiring hospitalization and clinical care, which will put pressure on countries’ health systems.
What about seriousness?
While the number of infections is significantly higher, the rate of mortality and even hospitalization is much lower than Delta.
This is supported by several studies, including a study by South African scientists who found that people diagnosed with Omicron over a two-month period were 80 percent less likely to be hospitalized than those infected with other types. However, scientists said the high level of immunity was partly behind the low need for hospitalization in the country.
“Compellingly, together our data actually suggest a positive story of the reduced severity of Omicron compared to other variants,” said Professor Cheryl Cohen from the National Institute for Communicable Diseases, one of the study’s authors.
Separately, research from the UK Health Protection Agency found the risk of hospitalization after being infected with the Omicron variant was half that of Delta. Furthermore, their study noted that the risk of hospitalization was reduced by 81 percent in those who received two and three doses of the Covid-19 vaccine, compared to non-vaccinated people.
In Scotland, researchers from the University of Edinburgh found that the number of Omicron patients who required hospitalization was 68 pc lower than in Delta. However, their study also underscored the increased risk of re-infection – 7.6 percent of the samples analyzed were re-infection compared with 0.7 pc with delta.
Another study conducted by Imperial College London suggested that the risk of hospitalization was 40 to 45pc lower for Omicron patients compared to the Delta version.
Earlier this month, Portuguese Prime Minister Antonio Costa said it was “clear that Omicron is less serious” as he announced the easing of restrictions despite a record increase in cases.
Closer to home, Indian health officials said only five to 10 pc patients in the current wave driven by Omicron need hospitalization as opposed to 20 to 23 pc in the previous wave powered by Delta.
However, the number of hospitalizations has not been low in all countries. There were 132,646 people hospitalized with Covid in the United States on January 10, surpassing the record 132,051 set in January 2021.
Elsewhere, France has seen the biggest increase in hospitalizations since April 2021, but well below the peaks set for the end of 2020. The country’s health minister said Omicron causes less serious complications, but hospitalizations were still on the rise because it was highly contagious.
Reading: N95, Surgical or Textile – Is one face mask better than another for optimal protection against omicrons?
Omicron affects the airways, not the lungs
Experts say that one of the reasons behind the reduced severity may be that omicrons multiply more rapidly in the airways and less in the lungs.
According to researchers from the University of Hong Kong, “24 hours after infection, the Omicron variant replicated approximately 70 times more than the delta version and the original Sars-CoV-2 virus. In contrast, the Omicron variant replicated less efficiently (more human 10 times less than the original Sars-CoV-2 virus) in lung tissue, which may suggest a lower severity of the disease.”
However, it cautioned that the overall threat from the version was “very significant” due to its increased transmittance.
according to a report by Guardian, six different studies found that Omicron does not cause as severe damage to the lungs as delta and other types.
Last week, WHO Incident Manager Abdi Mahmoud also said more evidence was emerging that Omicron caused less severe illness because it affected the upper respiratory tract.
“We’re seeing more and more studies that show that Omicron is infecting the upper part of the body as opposed to other [variants] which can lead to severe pneumonia,” he was quoted as saying Reuters,
Do current vaccines provide protection against omicrons?
While protection against Omicron may decrease after a few months of receiving two shots of one vaccine, several studies have shown that receiving a booster dose produces antibodies capable of fighting the new variant.
Early findings from a real-world analysis suggested that the risk of catching Omicron “reduced significantly after the booster vaccine”, said Dr Mary Ramsay, head of vaccination at the UK’s Health Protection Agency.
“Two doses of the AstraZeneca or Pfizer-BioNtech vaccines provided very low levels of protection against symptomatic infections compared to what they provided against Delta.
“However, when enhanced with a single dose of the Pfizer vaccine, there was approximately 70 pc protection against symptomatic infection for those who initially received AstraZeneca, and about 75 pc protection for those who received Pfizer, ” according to a Reuters report good.
Later studies also pointed to the same conclusion – booster doses provide protection against Omicron.
Danish researchers found that vaccine effectiveness was re-established for those receiving a shot of Pfizer or Moderna when they were given a booster dose of the Pfizer vaccine.
Research conducted by the pharmaceutical companies themselves has also yielded encouraging results. Pfizer said the three-course shot of its vaccine was able to neutralize the Omron version in a lab test. Its CEO also said that the company is working on an Omicron-specific vaccine that will be ready by March.
Moderna said a booster dose of its vaccine appears to be effective against Omicron, adding that it “promotes neutralizing antibody levels 37 times higher than pre-boost levels”.
A study from the University of Oxford supported the third dose of the AstraZeneca vaccine, concluding that it increased the level of neutralization.
However, research on higher doses of Chinese vaccines – Sinoform and Sinovac – has not been as encouraging.
A joint study conducted by the University of Hong Kong and the Chinese University of Hong Kong showed that the “third dose” [SinoVac] Given to those who. had received two previous doses of [SinoVac] does not provide sufficient levels of protective antibodies.”
Researchers from Shanghai Jiao Tong University and a Shanghai-based laboratory specializing in respiratory infectious diseases found that Sinopharm’s vaccine had “significantly reduced” neutralizing activity against the Omicron variant, although they noted the vaccine’s efficacy against Omicron. was not clear.
A later study suggested that a protein-based vaccine manufactured by Sinopharm “significantly improved the immune response against various Sars-CoV-2 strains, including Omicron” when administered after two doses of the original vaccine.
This time other treatments are also available. The US Food and Drug Administration (FDA) has approved two anti-viral pills – from Pfizer and Merck – that could be an important tool against Omicron.
Both companies said they expected their pills to be as effective as the new version.