To illustrate, a person with measles can infect 15 other people, while a person with the Omicron variant can infect 6 others. However, Omicron spreads more rapidly.
By
Atika Walujani Moedjiono
·4 minutes read
CHINATOPIX VIA AP
A worker wearing a protection suit sprays disinfectant as residents wearing face masks to protect from the coronavirus line up for the coronavirus test during a mass testing in north China's Tianjin municipality, Sunday, Jan. 9, 2022. Tianjin, a major Chinese port city near the capital Beijing, began mass testing of its 14 million residents on Sunday, after a cluster of a dozen of children and adults tested positive for COVID-19, including a few with the omicron variant.
The Omicron strain of Covid-19 is spreading extremely rapidly. Although it is said to cause only mild symptoms, several countries have reported deaths from the strain.
“Omicron is spreading at a rate never seen in previous strains,” World Health Organization (WHO) director-general Tedros Adhanom Ghebreyesus told a press conference on Tuesday (14/12/2021).
To illustrate, a person with measles can infect 15 other people, while a person with the Omicron variant can infect 6 others. However, Omicron spreads more rapidly. If one case of measles can spread the disease to 15 people in 12 days, one Omicron case can infect 6 people in 4 days. This means that from one case, 36 Omicron cases will be reported in 8 days, followed by 216 cases in the next 12 days.
The first Omicron case was detected in South Africa and reported to the WHO on 24 Nov. 2021. One month later, Omicron had spread to 108 countries to reach 151,368 cases and 26 deaths. In Indonesia, the first Omicron case was announced on Thursday (16/12/2021). By Friday (7/1/2022), at least 318 Omicron cases have been detected in Indonesia.
The WHO then declared it was a variant of concern (VOC) on 26 Nov. 2021, in accordance with the organization’s Technical Advisory Group on Virus Evolution (TAG-VE)
Omicron, also known as B.1.1529, was first detected in a sample collected on 9 Nov. 2021. The WHO then declared it was a variant of concern (VOC) on 26 Nov. 2021, in accordance with the organization’s Technical Advisory Group on Virus Evolution (TAG-VE).
The Omicron strain has 50 genetic mutations, 36 of which are found in the spike protein, the part of the virus that enables it to attach to human cells. As a result, the Omicron strain can attach to host cells more tightly as well as evade antibodies that have developed through vaccination or from a previous infection.
Rapid replication
A peer-reviewed study led by Michael Chan Chi-wai from the Li Ka Shing School of Medicine at the University of Hong Kong shows that the Omicron strain infects and replicates 70 times faster than both the Delta strain and the original SARS-CoV-2 in the bronchi (airways from the trachea to the lungs). In contrast, Omicron replicates 10 times slower in the lungs than the original virus.
AP PHOTO/ANDY WONG
A couple wearing face masks to protect from the coronavirus take a selfie with a tiger decoration, a Chinese zodiac which marks the year 2022, at a shopping mall in Beijing, Sunday, Jan. 9, 2022. Tianjin, a major Chinese port city near the capital Beijing, began mass testing of its 14 million residents on Sunday, after a cluster of a dozen of children and adults tested positive for COVID-19, including a few with the omicron variant.
These results support a study conducted by Wilfredo F. Garcia-Beltran, from the pathology department at Massachusetts General Hospital in Boston, Massachusetts, the United States, and an international team that was published on medRxiv on 14 Dec. 2021. Using a pseudovirus, the study found that Omicron’s spike protein could enter human cells much more easily than that of the Delta or the original SARS-CoV-2 strains. It found that the Omicron strain was four times more infectious than the original virus and two times more infectious than Delta. The research also emphasized the importance of giving vaccine booster doses to strengthen the body’s immune response to Covid-19.
On the other hand, due to the strain’s high concentration in the upper airway, Omicron was more easily transmitted by coughing, sneezing or spitting when a patient talks.
Brian J. Willet and his colleagues from the University of Glasgow in the United Kingdom found that the TMPRSS2 protein in the lung cells, which normally facilitates SARS-CoV-2 in gaining entry to the lung cells, bound less strongly to Omicron. As a result, the new strain had difficulty infecting the lung cells. On the other hand, due to the strain’s high concentration in the upper airway, Omicron was more easily transmitted by coughing, sneezing or spitting when a patient talks.
Although the strain had difficulty infecting the lungs, Chan pointed out, the severity of disease in humans was determined not only by the rate of viral replication, but also the host’s immune response to infection. Autoimmune disorders could cause a deadly cytokine storm.
At about the same time that Omicron was first reported, another new strain was also detected. Called B.1.640.2, it is also known as IHU, named after where the research team worked, the Institut Hospitalier Universitaire (IHU)-Méditerranée Infection in Marseille, France. The preprint report was uploaded by the team led by Didier Raoult to medRxiv on 29 Dec. 2021. The IHU strain reportedly has 46 mutations and 37 deletions that affect the viral spike protein in its genetic code.
MATTHEW HATCHER/GETTY IMAGES NORTH AMERICA/GETTY IMAGES VIA AFP
Members of the Ohio National Guard put on PPE as they prepare to administer COVID-19 tests at a drive through testing site on January 5, 2022 in Akron, Ohio. Due to the surge of the COVID-19 Omicron variant, Ohio Governor Mike DeWine deployed members of the Ohio National Guard to assist with medical personnel in health facilities and testing sites throughout Ohio.
According to the WHO, the strain was detected in a man who had just returned from Cameroon and then infected 11 other people. As long as it is spreading and replicating, SARS-CoV-2 will continue to mutate. New strains will continue to emerge, either weaker or stronger than previous strains.
