1. Mutations
Omicron is the latest variant of SARS-CoV-2 and it is also the one that has the most mutations. It has been found that it has over 31 mutations on the spike protein (the protein that allows Covid-19 to enter host cells and cause infection) and the receptor-binding domain has a number of 10 in it.
Omicron managed to keep several mutations that were found in previous variants, such as Delta and Alpha, but it also came with a new set of changes, that weren’t seen anywhere before.
In conformity with Kristian Andersen, an infectious disease researcher at Scripps Research, the mutations are not important on their own, but their combination is the one that makes things difficult.
Due to the several mutations that are found in the spike protein, the virus is becoming more able to infect host cells and evade immunity.
Delta, on the other hand, has only 13 mutations, with 9 of them being in the spike protein. In conformity with Suresh V. Kuchipudi of Penn State University, who researches viral evolution, two of them are in a molecular hook called the “receptor-binding domain”. This helps it adhere to cells more tightly and strongly.
2. Contagion
As we already know, people who are not vaccinated are at a higher risk of contracting Covid-19, and also have more serious symptoms.
Delta: Usually, the first variant of SARS-CoV-2 can spread from one person to three, while Delta can infect six. In addition to that, Delta has a four-day incubation time, which is shorter than the original Covid-19’s six-day incubation period. This can make people more contagious immediately.
Omicron: Unfortunately, we have no idea regarding the transmission rate or incubation period. However, the high number of cases in South Africa is really concerning. According to Trevor Bedford, an expert on viral evolution and surveillance at the Fred Hutchinson Cancer Research Center in Seattle, this suggests that Omicron is stronger than Delta in that country.
However, this does not mean that Omicron is more transmissible than Delta on a fundamental level. Instead, it might be stronger at evading our immune systems.
3. Immune eluding
People who have been previously infected and vaccinated are in danger due to a variation that can escape our antibodies. However, this isn’t all bad news because vaccines can be redesigned to be more protective.
Delta: This variant has a few mutations that allow the virus to escape antibodies induced by the vaccine. This can explain the vaccine’s “breakthroughs”.
There is evidence that shows that Delta is linked to an increased risk of reinfection. Older strains produced antibodies that were useful in protecting people.
Omicron: Although we don’t have that much information, scientists are looking for information that will help them compare Omicron and the antibodies of people who only got the first two shots of the vaccine, versus those who got the booster as well.
On the other hand, the presence of Omicron in a vaccinated San Francisco resident suggests that two doses are insufficient to protect us. Furthermore, when compared to Delta, a newly released analysis of epidemiological data from South Africa showed a three-fold increase in the possibility of reinfection due to Omicron.
