The Omicron variant of the Corona virus is said to be more contagious than the Delta variant, so it can trigger a new wave of COVID-19. Experts reveal the cause.
Omicron is more infectious than Delta because of its ability to evade antibody elimination, but the severity of infection is lower.
In the delta variant spike protein there are only 9 amino acid mutations, and 2 of them are in the receptor binding domain (RBD). This change makes the Delta variant avoid an immune response, especially in this case, an increase in antibodies, neutralizing viruses that are already present in someone who has been vaccinated and who has not been vaccinated.
In the Omicron variant, he explained, the number of mutations increased sharply. The entire viral genome has about 50-60 mutations, 30 of which are in the spike protein, and 15 of them are in the RBD.
"RBD is part of the spike protein which is then responsible for the increase in its receptor. This allows Omicron to better evade neutralization by antibodies that were previously formed by either the previous variant, or vaccination, even after two vaccinations," he explained.
Lower infection rate
Although more infectious than Delta due to its ability to evade antibody elimination, the severity of Omicron infection is lower.
Based on the study, there was a reduction in the risk of hospitalization by the Omicron versus Delta variant at the population level by 40-45%.
In addition, the Omicron variant also showed a 74% reduction in hospitalization in the emergency department (IGD) compared to Delta, and a 70% reduction in length of stay in the ED for the infected compared to Delta.
According to the study, the severity of Omicron infection is lower, mainly because the Omicron variant attacks cells in the upper respiratory tract.
"The Omicron variant is not sufficiently capable of attacking lung cells so that the attack on lung cells is lower than Delta. However, due to the ease of infecting, finally this Omicron variant infects the upper respiratory tract more," he explained.
Need a booster vaccine
Seeing the characteristics of the Omicron variant which is able to evade immunity, a third or booster dose of vaccination is required.
The effectiveness of the vaccine is indeed much lower by the Omicron variant, but a booster can be done so that the protection becomes higher.
However, he also warned that over time the booster vaccination will decrease in effectiveness, approximately after 2.5 months of giving the booster.
The decrease in booster effectiveness is likely to be more pronounced than the decrease in protection after the second stage of vaccination. According to him, the Omicron variant can add to more severe infections in a person and hospitalization for those who have not been vaccinated.
If a person has been vaccinated, the chances of having to be hospitalized are much lower than those who have not been vaccinated. So vaccines still protect, boosters are especially important to reduce the risk of infection, severe impact of infection and hospitalization.