Omicron variant: Are we ready to fight back?

The SARS CoV-2 virus needs no further introduction. If you ask anyone on the street, they can tell you all about the virus and how bad it really is. There is not a single family who did not lose a loved one to this pandemic. 

Global infection now stands at over 293 million and deaths have surpassed 5.45 million. Globally, case numbers are rising exponentially every day. On 3 January 2022 global case numbers rose close to 2 million and the USA alone got over one million cases in a single day. 

Whenever we think we have some kind of grip on this virus, it resurfaces. It has only been a few weeks since we have been notified about a variant called Omicron by South African scientists and it has already created a new concern worldwide and it seems like we are going back to square one. 

Omicron has already proved to be highly transmissible and less susceptible to vaccines compared to other variants such as alpha, beta and delta. Some forms of treatments like 'Regeneron monoclonal cocktail' which we found promising are also failing. 

One Canadian immunologist described this virus as such, "It is kind of like a boxer who has taken a hit and is up against the ropes, who simply shakes it off and gets back into the fight with renewed strength and techniques."  

Now, what should we do? Sit tight and do nothing?  Or should we fight back?  We do not have any other option other than the latter. 

Now the question arises, are we prepared? First of all, we need to go back to the basics. Wear a mask, maintain physical distance and wash hands or sanitise them frequently. Fortunately, Bangladesh is not feeling the impact of the Delta or the Omicron variant yet. 

But case numbers have already started creeping up and they will most likely go up sharply soon. People seem to have forgotten about Covid-19. In Dhaka and other cities, barely anyone wears masks on the streets but hopefully, the government's recent 15 points direction will force everyone to adhere to public health regulations. 

Healthcare professionals, especially physicians dealing with the virus directly and laboratorians need to be on top of the situation and need to learn more about this variant so we can come up with the right strategies and build our arsenals more effectively.

The Omicron variant has already been found in over 100 countries, and the case numbers are rising astronomically. Most European and North American countries are breaking their single day case number records every day and numbers are doubling almost every few days and may see peaks by the end of January or early February 2022.

A few important factors are making healthcare professionals nervous about this new variant. Firstly, this is highly transmissible. Secondly, this variant can seemingly evade the immune system much more easily compared to the other variants thus making vaccines less effective. Thirdly, monoclonal antibody-based treatment is failing for some patients, and although it seems less severe, due to the huge number of cases, hospitals could become plugged up so there will be a crisis of beds and providing patients with other severe diseases like heart attack, strokes, kidney failures, terminal cancers to name a few might also become more challenging. 

So, healthcare professionals and government agencies should take this variant seriously and act diligently.

Common Covid-19 symptoms for alpha and beta variants were fever, dry cough, loss of taste and shortness of breath for serious cases. However, the Omicron variant is showing a different set of symptoms, i.e., severe headache, severe fatigue, runny nose, sore throat and sneezing. 

So far, we have seen this virus is highly contagious compared to any of other variants such as alpha, beta or delta. It is difficult to give an exact estimate but now it is clear that this Omicron variant is spreading faster wherever it goes. 

In British Columbia, we have seen a 50 percent increase of Omicron variant cases within a week of the first reported case of this variant and this is the same across the rest of Canada as well as all other countries.  In fact, in most countries, Omicron has now become the dominant variant. 

Bangladesh is no exception and in no time will experience the same. There is another piece of scientific evidence that will explain why this virus is so highly transmissible. 

Researchers from Switzerland discovered that one of the receptors of human cells called ACE 2  has an elevated affinity to allow this virus to enter into the human cell easily and allow them to multiply in millions very quickly. Another scientific paper mentioned this virus colourised more in lung bronchus (pipe) rather than in lung tissues and that is why during exhalation, infected people spread the virus to the air more and infect more people. 

The good news is that since the Omicron variant does not damage the lung tissue much, that means it causes milder symptoms compared to other variants. The existing data and mathematical modelling show that one patient infected with the Omicron variant may transmit the virus to 4 to 5 vaccinated as well as unvaccinated individuals and this number is much higher than what we dealt with previously. A recent study showed Omicron variant infects and multiplies 70 times faster than the Delta variant in the human bronchus and replicate 10 times lesser in human lung tissue compared to the original SARS coV-2 virus.

Since a considerable number of people in Bangladesh by now have gotten at least one dose of the  Covid-19 vaccine with some even receiving a booster dose it will be difficult to measure the true severity of this variant. 

But it is agreed the vast majority of cases are mild. However, we are definitely seeing more hospitalisations because of the increased number of cases. Even countries with high vaccination rates such as Canada are already experiencing new infections through the Omicron variant. Maybe, vaccine-induced immunity is waning in vaccinated populations because six months or more have already passed between their getting their second jabs and now. 

Few studies have already demonstrated that antibodies produced either due to vaccination or a neutral infection are twenty to forty times less capable of neutralising the Omicron variant and as result, we are experiencing a higher number of breakthrough infections with this variant. 

Another point could be, this variant has over 30 mutations in its genome related to spike protein which attaches to human cells and allows easy entry to human cells thus multiplying inside human cells easily. There is some data on vaccine efficacy on the Omicron variant coming out as well. South African studies showed that two doses of the Pfizer-BioNTech vaccine had effectiveness against Omicron infection of just 33 percent. 

To put it in context, for other variants, its effectiveness was 80 percent. UK scientists found that people who had received two doses of the AstraZeneca vaccine had no protection at all from infection from Omicron six months after vaccination. Two doses of Pfizer-BioNTech had an effectiveness of just 34 percent. 

Then the obvious question comes to our mind, why should we bother with vaccination? Yes, we still need to be vaccinated and the sooner we get vaccinated the better. 

Antibodies are just one aspect of our immune system. When we get vaccinated our body produces weapons other than antibodies to deal with the infection. 

So even though a vaccinated individual might get infected with the Omicron variant, the severity will be much lower and very rarely fatal. Moreover, the good news is that new data also showed a Pfizer-BioNTech booster dose (3rd dose) had an effectiveness of 75 percent against infection from Omicron. I think the same will apply to other mRNA vaccines. 

Many companies are also trying to come up with vaccines for multiple variants. One recent publication shows that people who have received three doses of vaccination are mostly protected from the omicron variant  followed by people with natural infection and then people who have received two jabs

SARS CoV-2 virus has re-evolved and re-emerged with new vigour so we too need to rethink our strategy. We need to go back to the basics and start following community safety guidelines again.

In addition, It would be wise to expand the diagnostic capacities not only for RT PCR tasting but also for rapid antigen testing. The global community should not take this Omicron variant lightly and neither should a densely populated country like Bangladesh.

Dr Muhammad Morshed is an international expert on zoonotic and arthropod-borne diseases. He is a clinical microbiologist and head, zoonotic diseases and emerging pathogens at BC Centre for Disease Control and clinical professor, department of pathology and laboratory medicine, University of British Columbia.