BY PRABIR PURKAYASTHA
The news of the opening up of China from the Covid-19 protocols and its current epidemic has overtaken the threat of two emerging SARSCoV-2 lineages
– XBB and BQ.1. China is seeing the spread of BF.7, which is much closer to the original Omicron strain. Our existing immunity, from either vaccines or
infections, should therefore continue to protect us from infections partially and much better against serious infections.
The threat of the Chinese variant, as the news media calls it, is much lower than that from the US and Europe. This has nothing to do with the
geography of the virus: it is simply the genetic distance of these subvariants from what our bodies saw, either as vaccines or as previous infections. Eric
Topol, the founder-director of Scripps Research Institute and a professor of molecular medicine there, has talked about variants of the SARS-CoV-
2virus, which we need to worry about and “scariants”. Scariants are variants used to create fear and scare us but are only another strain, of which
hundred sexist at any given time. In the Topol nomenclature, XBB and BQ.1 strains are variants to worry about, while the Chinese BF.7 may only be a
scariant!
I am not getting into how the virus strains are named. The question here is not who is descended from who but how different these subvariantsare
from the original omicron strain. While BF.7, the dominant subvariant in China, is not that distant from the original omicron variant, the BQ.1 andXBB
subvariants are quite distant. It also matters where the mutations are; if they are in the spike protein region, it may improve their ability to infectus. Again
BQ.1 and XBB subvariants have major changes in the spike protein, meaning it has an improved ability to bypass our immunity in the initial stages of the
infections.
Why should this matter to us? Eric Topol talks about three properties of any new variant. Is it more virulent? Does it cause more deaths? Or is it more
infectious, transmitting more easily from person to person? Or is it more immune evasive, meaning that even if we have been either vaccinated or
infected, the body's immune system does not recognise it, and we can therefore be infected again.
Initially, the success of the “new” lineages was due to greater transmissibility, the ease with which they could infect people. With a population which
has now either been already infected or has received multiple vaccine doses, the success of the current variants is based on how effective they are in
evading our immune system. If they are more effective in escaping our immune system than other variants, the new strain will emerge as a variant of
concern among the hundreds of new subvariants that are emerging continuously.
The BQ and XBB subvariants ofSARS-CoV-2 Omicron are now rapidly expanding in North America and in Europe. The journal Cell has reported a study,
titled, “Alarming antibody evasion properties of rising SARS-CoV-2BQ and XBB subvariants”. The paper concludes “… that neutralisation ofBQ.1, BQ.1.1,
XBB, and XBB.1 by sera from vaccines (vaccinated persons: author) and infected persons was markedly impaired.” This included a bivalent mRNA vaccine
as well, meaning that even if a new bivalent mRNA vaccine is used, the results are not significantly different. The Cell paper continues, “Monoclonal
antibodies capable of neutralizing the original Omicron variant were again largely inactive against these new subvariants… Together, our findings indicate
that BQ and XBB subvariants present serious threats to currentCOVID-19 vaccines, render inactive all authorised antibodies, and may have gained
dominance in the population because of their advantage in evading antibodies.”
Why is then so much noise over the Chinese BF.7, which does not appear to have the immune escape properties of the BQ.1 and XBB
subvariants? Even in India, while we are focusing more on incoming passengers from China, which is also what European and the US are also
doing, what are the preparations for the new subvariants? The XBB.1.5 strain has emerged in the last two weeks as the dominant strain in the US
and is likely to take over globally as well.
The reason for fearing passengers from China and asking for Covid tests is that after relaxing China's zero-Covid policies, there is now an explosion
of Covid in China. Therefore the need to test that Chinese passengers are free of Covid before they start their journey from China and test a sample
after disembarking. While China has condemned these measures as discriminatory, they are as much political as epidemiological measures.
Before China relaxed the Covid restrictions of its zero Covid policy, the western media was campaigning about how China was wrecking its
economy with this disastrous policy. Once the zero Covid policy has actually been relaxed in China, they have now gone to town on the disaster of
China's lifting its Covid restrictions. Damned if you do, and damned if you don't!
China's zero Covid policy, particularly when the virus was completely new and during the delta version, saved millions of lives. When the US saw 1.1
million deaths, India530,000, and China saw about 5,000,a minuscule number. A detailed article by Tings Chack in MR Online (mronline.org) dated
January 1, 2023, has explained why China pursued its zero Covid policy. When the Covid-19 pandemic started, China, with a population five times that
of the US, had only 1/10th of the ICU beds that the US had. China took the last three years to strengthen its public health infrastructure before it lifted the
Covid restrictions.
The Chinese government's changing Covid-19 from a Class A toa Class B disease means the reporting becomes once a month. But with the
numbers rising quickly, a lack of official numbers only fuels speculation that China is hiding its data because it is so bad and hundreds of thousands are
dying. In major urban centres, where the numbers have risen steeply over the last 30 days, reports in social media of hospital collapses and overflowing
mortuaries do not seem to be on a scale that we saw in Wuhan initially or in different parts of the world during the delta spikes. It will be much more
helpful for China if the official numbers are released. Of course, in such a huge spike as we are now witnessing, the testing infrastructure faces
tremendous problems carrying out millions of tests daily. But this is one part of China's infrastructure that should weather this storm better, as earlier,
China was testing millions every day.
I expect the total number of those infected, including those who have recovered, to be in the hundreds of millions. But the peak appears to be now
receding in major urban areas. There are still two challenges before China: a) handle the serious cases that peak after 2-3 weeks in urban areas, b)
address the inevitable rise of numbers in rural China that will follow the urban peak. As we have written in these columns, a large number of deaths
occur when the health infrastructure collapses and is overwhelmed by a very large number of serious cases. The unavailability of ICU beds and shortage
of oxygen led to high death rates during our delta peak in late 2020, asit did in other parts of the world. This is the test that China will need to pass.
Though China has increased its ICU beds 2.4 fold in the last three years, the high numbers of infected can still overwhelm the ICUs, particularly in the
rural areas.
Everywhere, the omicron spikes produced a high number of infections. Though the deaths per 100,000 were much lower than in the delta variant, the much
higher number of infections meant that in absolute terms, there was also a high number of deaths, particularly among the unvaccinated. In China, contrary to
western media campaigns, most people have been vaccinated with two doses, and its booster dose numbers are higher than in countries like the US. Given
that not all those vulnerable – the older population and those who are immune compromised – have received booster doses, China needs to target this section
with boosters, particularly using its new adenovirus vector nasal vaccine.
We need to address the question, will the raging omicron infections in China produce new and more dangerous variants? There is no evidence that it
has. The genome sequences that China is submitting to the global GISAIDs and testing of passengers from flights from China show the subvariant of
BF.7 is still the dominant strain in China. This variant is much closer genetically to the omicron virus that swept the world earlier, and our immunity, both
from vaccines and previous infections, should provide immunity against this strain. Though the government has issued various warnings against the
Chinese subvariant BF.7, the danger – given air traffic between the US, the UK and India – is from XBB.1.5, which is rapidly emerging as the dominant
strain in the US. And as we know, if the US leads, the UK and EU will surely follow!
India has successfully run clinical trials using the adenovirus vector nasal vaccine. This should rapidly before grounded in our Covid preparedness,
not so much for the Chinese BF.7 strain but the XBB.1.5 strain. Though today, we are much better equipped in terms of knowledge on how to treat
Covid-19 and its various manifestations, the challenge remains for implementing this knowledge, particularly if and when a new wave appears.
(IPA Service)
