Dr. Shyam P Lohani

Recently, a new coronavirus variant has been found with an unprecedented number of mutations within its spike protein and it is feared that some of which will help the virus to evade vaccine-induced and/or infection-induced immune protection. The virus was named Omicron by the World Health Organisation (WHO) on November 26, and called it a Variant of Concern (VOC).

There is a scientific process of designating any variant either to Variant of Interest (VOI) or VOC. VOI is designated to those which have potential to alter the transmissibility of a virus and capable to affect diagnostics, treatments, or vaccines; or appear to be accountable for an increased number of cases. VOCs meet all those criteria, but also show increased evidence of transmissibility or disease susceptibility, as well as public health measures, diagnostics, vaccines, and treatments, which are less likely to be effective against it.

Global alarm
Although the full implications of the new variant are still unclear, it has sparked global alarm among scientists and public health officials owing to its unprecedented number of genetic mutations. The newspapers and social media have recently published a series of articles on its transmissibility and pathogenicity, but the full consequences of those genetic mutations are yet unclear and may take several days or weeks before the clear picture of its virulence is revealed. It has been found that there are 50 mutations in the new variant named Omicron, out of which more than 30 are on the spike protein, the uncovered part of the virus that binds with human cells. Those mutations on the spike protein could make it more transmissible than the dominant Delta variant and more likely to evade the immune protection induced by vaccines or previous infection.

The development of a new variant has left public health professionals worried mainly for two main reasons. First one is an epidemiological reason as the speed with which the variant first detected last month is spreading in South Africa. The unique mutation pattern of Omicron can easily be detected by conventional PCR and is capable of distinguishing it from other variants, which will help us to avoid the need of full genome sequencing. The other reason is the highly unusual and large number of mutations in the genetic profile of the Omicron. It has an unprecedented set of mutations from four earlier variants of concern: Alpha, Beta, Gamma, and Delta. There are other genetic changes that were not seen before but the significance of which is yet to be understood.

These mutations might help the virus circumvent the immune defense mechanism of our body because it is trained by vaccines or previous infection to fight the original strain first detected in Wuhan, China. This concern has rightly been raised owing to only three mutations in the spike protein of the Delta variant which has reduced the effectiveness of vaccines. First detected in samples from Botswana and South Africa, it is still not known where Omicron was originated and how it acquired so many changes in its genetic sequence than the previous variant. However, it has been postulated that the variant is likely to have evolved from a single individual who probably had compromised immune system through medical treatment and/or disease such as HIV/AIDS.

Omicron is spreading rapidly around the world. Newly detected two cases in the UK and a case in Hong Kong were in travelers who were in South Africa recently. Cases have appeared in around 20 countries: Australia, Austria, Botswana, Brazil, Canada, Czech Republic, Denmark, France, Germany, Israel, Italy, Japan, The Netherlands, Nigeria, Norway, Portugal, Saudi Arabia, Spain, and Sweden.

The discovery of a new variant called Omicron has provoked considerable panic across the globe, with a number of countries banning flights from South Africa and many countries barring the entry of foreign travelers completely. The public health experts globally have urged caution, noting that there is as yet no firm evidence that Omicron is more dangerous than previous variants like Delta, which quickly overtook its predecessors in the countries around the world and still is the dominant variant worldwide.

It is yet unclear whether it is more transmissible and capable of causing more serious illness than other variants. There is some evidence the variant can re-infect people more easily. However, whether Omicron is capable of evading the immune system induced by vaccines or prior infection is yet not known. The widely used PCR is still capable of detecting coronavirus infections including infection caused by Omicron and corticosteroids and IL6 receptor blockers are still effective in managing patients with severe coronavirus infection.

Surveillance
At the present time, scientists and public health professionals are eagerly waiting for data and scientific evidence to better understand the behavior of Omicron. Researchers around the world are currently carrying out studies on assessments of transmissibility, the severity of infection and symptoms caused by Omicron, the performance of vaccines and effectiveness of diagnostic tests, and the effectiveness of already available and new treatments.

It is, therefore, waiting time for us to see how mutations in Omicron change the behaviour of the coronavirus. The importance of continued surveillance is paramount at this time of the pandemic. The public should not panic and continue adhering to public health protective measures such as social distancing, mask-wearing, restricting from unnecessary traveling, avoiding large crowds, and vaccination to contain its spread.

(Prof. Lohani is the founder and academic director at Nobel College. lohanis@gmail.com)