Delta Variant Vs Omicron Variant - Which Is More Infectious? read

Jan 17 2022


As the number of positive cases for the Omicron variant across the globe is rising, the questions around it are also increasing. Which variant is more infectious – the Delta variant or the Omicron variant? Is Omicron more fatal than other variants? Should the world prepare its healthcare system for the next big wave?

Since many weeks have passed after the first case of Omicron was registered, scientists across the globe are able to conduct studies on the transmittabitability and severeness of the Omicron variant. The early results of these studies have many things to say about the Omicron variant. Let’s find out.

Is The Omicron Variant More Infectious?

A study done in Denmark on the transmissibility of the new variant suggests that it is more infectious than other variants. When compared to the Delta variant, the Omicron variant is found to be 2.7 to 3.7 times more infectious among vaccinated people.

There can be many reasons why a virus can be highly transmissible. For example, a virus might be lingering in the air for more time or its ability to latch onto the human cells might be high. Another reason can be a virus’s efficiency at evading the human body’s immune system.

The reason behind the high infection rate of the Omicron variant is ascribed to its unique ability at circumventing the immune system of people who are vaccinated.

The study that found these results was done on 12,000 households in Denmark in mid-December. It was conducted jointly by researchers at Statens Serum Institut (SSI), Statistics Denmark, and the University of Copenhagen. What is startling about the results of this study is that this high rate of infection is found among the vaccinated Danes.

Another noticeable characteristic of the Omicron variant mentioned in the study is that the rapid spread of Omicron is not because of its inherent capability of basic transmissibility. Rather, the primary reason for rapid spread is the immune evasiveness.

The seventy-eight percent of the households on which this study was conducted were fully vaccinated with the Pfizer-BioNTech's vaccine. Around forty-eight percent of these households even had received a third booster dose of the vaccine.

The first case of this highly transmittable Omicron variant of the coronavirus was discovered in South Africa in November. Since then, the variant has been detected in several countries including India. Most of these countries have also started reporting deaths among the Omicron positive patients.

With this new threat lingering around, Scientists have started racing to find out how this new variant enters the human body and the body’s immune system reacts to it. The early numbers are suggesting that this variant is more contagious than any other previous variant of coronavirus.

Another finding of this study is that people who are vaccinated with booster doses are less likely to get infected and transmit the virus than people who are not vaccinated. This holds true for the Omicron variant and other variants like the Delta variant. It needs to be mentioned here that this study is yet to be peer-reviewed.

Is The Omicron Variant More Fatal Than Other Variants?

Another pertinent question around the Omicron variant is whether it can induce serious disease and prove to be more fatal than the others or not. The findings of the study came out as a piece of good news.

SSI’s technical director Tyra Grove Krause, who is considered as a leading voice on the pandemic situation and is also part of the study, said that the new variant is more transmissible than other variants but it seems that it does not induce a more serious disease than the other variants.

The rate of positive cases of Omicron variant who are hospitalized was half of the rate of Delta variant. This indicates that the new variant is milder than earlier variants. That being said, Tyra Grove Krause thinks that it will still be able to put a load on the healthcare system of countries.

Not just the rate of hospitalization, the rate of people who needed intensive care was also less. The data of the Danish study showed that 93 COVID-19 patients were hospitalized as their health started to deteriorate.

Out of these 93 people, only five people required intensive care. Seeing these results, Krause believes that the Omicron variant wave might as well be the last wave of the COVID-19 virus.

The results of the Danish studies match with some other major studies done in the UK, South Africa, and Hong Kong. The studies suggest that the Omicron positive cases are less likely to be hospitalized or need intensive care as compared to that of the last COVID-19 wave.

The chances of the requirement of hospital care are even less for the people who are re-infected with the COVID-19 virus. In simpler words, if you have caught Omicron infection after recovering from Delta variant or other previous variant infections, you are less likely to need hospital care.


To sum up the results of these studies, the new variant is extremely contagious, but it produces fewer symptoms than its predecessors like the Delta variant. However, most of these studies are published ahead of peer review. To be more sure about the virus’ transmissibility and its fatality rate, peer review of these studies is being awaited.


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