Now another strain of Omicron!

Syed Fattahul Alim | Monday, 31 January 2022

Even as the Omicron variant of the SARS-Cov-2 coronavirus is spreading fast replacing the previous, deadlier, Delta variant, reports about yet another Omicron variant, BA.2, is causing concern. Is it coronavirus's anotherVariant of Concern(VOC)? Going by the WorldHealth Organization (WHO), it is not so, though it has warned all about BA.2's higher transmissibility. According to the Danish scientists, BA.2 is 1.5 times more transmissible than the previous one, BA.1. It is worthwhile to note that the Omicron variant is actually the common name of an entire family of coronavirus that was detected in November last year. So far, the variant, BA.1, had been circulating around the globe. But its days appear to be numbered as its subvariant has been replacing it very fast. As we already know, BA.1 had 32 mutations in its genome in the area that encode Spike or S protein that attaches itself to the receptor in the cell of a human body. This new Omicron subvariant, (BA.2) also has those 32 mutations. But it has 28 mutations that are different from BA.1. It (BA.1) was detected in November 2021.The new subvariant, BA.2, on the other hand, was identified a few days back (in January) in South Africa.

In Denmark, this new  subvariant of the Omicron has overtaken the previous strain. In the US, this subvariant dominates the cases in half of its states. At this pace, it may soon overtake all existing Omicron cases in the remaining parts of America. It is also spreading like this in the UK, India and northern European  countries including Norway and Sweden.

But what should be the level of preparedness against this new version of the Omicron?  Though BA.2 appears to be less harmful than the earlier version BA.1, it does not mean that it can be overlooked. In fact, for unvaccinated people, it may prove be harmful like other variants of the coronavirus. It would also be so for those who had not earlier been infected by Omicron.  In that case, if BA.2 infects some people, even if they are not taken seriously ill, they may still pose risk for others infected by the virus. At a stage, it may become fatal for someone in that chain. However, for fully vaccinated people with booster dose, and those with a history of being infected by Omicron BA.1, the risks are lower. So far, the data are not sufficient to say that if BA.1-infected  people would be immune from BA.2. Even so, scientists hope, such people would be immune from BA.2. The probability of their being immune would  be stronger, if they are also vaccinated. For, scientists believe, the antibodies created in human body as a result of BA.1 infection, would provide a reasonable level of protection against BA.2.

Interestingly, vaccines now in use have been found to be better at giving people protection against BA.2 than it used to be against BA.1. For the UK Health Security Service says that people receiving three doses of vaccine are in 70 per cent cases safe from symptomatic infections of BA.2 two weeks after the third, booster, dose of the vaccine. What is worth noting here is that if the infections have been caused by BA.1, vaccination will be effective against 63 per cent of the cases. Further, the efficacy level of the vaccine for those who got only two doses of the jab, it was found to be effective for BA.2 in 13 per cent cases 25 weeks after inoculation. For BA.1, on the other hand, the jab is effective for 9 per cent cases after the same period of time.

According to the result, BA.2 seems to be less risky or severe than BA.1, though it is 1.5 more transmissible than the later. It means, with increased level of  infection, more people will be hospitalised. And for that reason, the percentage of fatalities will also increase.

Anyway, the best protection against the subvariant of Omicron, BA.2, is getting jabs with booster doses. And, of course, the observance of the health guidelines should continue as usual.


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