Omicron: More Findings Come in, With Some Questions Still Remaining

It has been almost a month since the new variant, Omicron, first emerged. But, scientists from many countries are devoting much time to dig out dangers that this variant can pose to humanity. Some of these are worrying, while some provide a glimmer of hope. For example, a study conducted in South Africa, where the variant was first discovered, reported ominous data suggesting that the variant can cause re-infection in people, which is a sign of evading the immune response. The study showed that Omicron could cause infection among those who have recovered from the previous infection by other variants. Researches are still undergoing, with newer facts pouring in each passing day. However, the data is scarce and incomplete yet.

Let us look at some aspects of the infections caused by the variant, which are of serious concern.

Rate of Hospitalisation:

Infection by the coronavirus is one thing, but the rate of severe patients among those infected is another issue. An increase in the severity rate means overburdening of the hospitals and an accompanying health crisis, which the world has witnessed in several waves of the pandemic. Remember the situation India had to face early this year when the second wave ravaged the country's health care system.

As far as Omicron is concerned, early and preliminary data offers some hope. Reports from South Africa have been consistent in saying that the hospitalisation rate is lower in the case of Omicron compared to infection caused by the Delta variant. Discovery Health, a private health insurer in South Africa, has recently said that the hospitalisation rate is 29% lower in Omicron infections than infection by previous variants. This might influence us to think that Omicron causes less severe diseases than previous variants. But, researchers caution that it is still too early to conclude as such.

On the other hand, a report published by Imperial College London on December 16 said that there is no evidence of a reduced hospitalisation rate in patients infected by Omicron compared to that by Delta. The report was based on a study in England. However, the sample size in the study was too small to say something definitively. Similarly, a report from Denmark on December 13 said that the hospitalisation rate of Omicron infected people is similar to those infected by other variants. Again, this report also catered for a small sample size—3400 cases of Omicron infection and only 37 hospitalisations.

Protection By Vaccines:

Early laboratory studies suggested that Omicron may evade some protections provided by the COVID vaccines. Data from UK Health Security Agency says that vaccines are not that protective against Omicron as against other variants. However, there is contrary evidence, with experts believing that existing vaccines can still protect many people who have received the full doses of the vaccines.

Researchers have studied the range of mutations in SARS-CoV-2, the coronavirus behind the pandemic, including the protein fragments recognised by T cells (a type of cell in the immune system to fight off an infection) after natural infection or vaccination. Noted virologist Alessandro Sette of the La Jolla Institute for Immunology, California, commented on it, saying, "In the case of vaccination, more than 70% of the fragments are fully intact."

However, more studies need to be explicitly directed on T cell protection and vaccine protection. Till now, we don't have a clear way of determining a link between T cell protection and disease severity vis a vis Omicron.

Infection Among Children:

The effect of Omicron on children has not been studied extensively yet, as data on the aspects mentioned earlier are still awaited to say something definitively. However, some early hints are available- this too from South Africa. The data available till now suggest that Omicron infected children are hospitalised at a higher rate than was observed in previous waves. However, this is not conclusive to mean that children are more vulnerable. One crucial point here is that children had a lower infection rate in earlier waves and hence a lower level of pre-existing immunity.

David Dowdy, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, raised a crucial point about the importance of host environment interaction and children infectivity.

"The setting in which children are exposed can also play a part: extended exposures at home from an infected parent could mean higher initial exposure to the virus than a transient exposure at school. Everyone is focused on the pathogen here, But it's not just about the variant, it's also about the host and the environment," Dowdy said.