Virus variants in Asia threaten the whole world

According to genome databases such as nextstrain.org, there are now more than 1,000 known variants of the SARS CoV-2 virus.

Up to now, the "variants of concern" have been named after the places where they were first discovered. But in a move to avoid stigmatising particular countries, the World Health Organisation (WHO) has now introduced a new naming system based on the letters of the Greek alphabet. The UK/Kent, South African, Brazilian, and Indian variants will now be given the letters Alpha, Beta, Gamma, and Delta, respectively. But the labels will not replace their more complex scientific names.

The new variant discovered in Vietnam appears to be a cross between Alpha (B.1.1.7) and Delta (B.1.617). According to Vietnam Health Minister Nguyen Thanh Long, the new strain spreads "quickly by air," which could explain the rapid rise in the number of new infections in May.

Until now, Vietnam had escaped relatively lightly, recording some 3,500 confirmed cases and 47 deaths from the beginning of the pandemic to the start of May 2021. The government successfully contained COVID-19 outbreaks by imposing a brief but strict lockdown and comprehensive quarantine restrictions.

But since May, Vietnam has already recorded more than 3,000 new cases — above all in the provinces of Bac Ninh and Bac Giang, where hundreds of thousands of people work in huge production facilities for international technology enterprises.

Determining the course of the pandemic

One might think that those numbers are still relatively low, but the new variants in Asia and elsewhere should be of concern to everyone wherever they live. And that is not just because it means that the pandemic will continue to cause more suffering and deprivation worldwide.

In the medium term, the Northern Hemisphere could also be affected again despite extensive vaccination programmes. In a globalised world, such variants spread fast. And if these new strains increasingly adapt to their human hosts, then our antibodies — formed either by vaccination or infection — will no longer protect us at some point. The antigen or PCR tests would no longer detect the variants and instead produce false negatives. And the vaccinations available would also gradually stop working.

That makes it vital to identify variants as quickly as possible using genetic sequencing to ensure that sufficient amounts of the right types of vaccines are available globally and not just in wealthy nations.  

Why is sequencing so important?

Alongside the four apparently most dangerous "variants of concern," there are hybrid strains, such as the one in Vietnam. Some have been around for some time. Yet many of these variants are detected only by chance, as many countries simply do not have sequencing facilities.

To be able to fight the virus, we have to able to unlock its genetic code, and that is possible only with genomic sequencing. Next-generation sequencing (NGS) methods enable scientists to decode the entire viral genome base by base. Researchers can detect minuscule changes in the genetic make-up of the virus by looking at fragments of DNA — and thus determine the origin and the spread pattern of variants. And that is the only way of developing appropriate vaccines.

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Different strains and the wrong vaccines

There are many indications that virus variants are primarily responsible for the current outbreaks in various parts of Asia. In Sri Lanka and Cambodia, the Alpha (B.1.1.7) strain is predominant. From what we know at the moment, the mRNA vaccines produced by BioNtech-Pfizer and Moderna are an effective weapon against that variant. And mRNA vaccines can be adapted relatively swiftly. The AstraZeneca vaccine also offers good protection.

In India and further northwest in Nepal, however, the Delta variant (B.1.617) has already spread extensively. Nepal has, as a result, seen a steep rise in the number of recorded COVID-19 cases since mid-April. Nepal has been worse hit than India in proportion to its population size. 

Genomic sequencing conducted by the Indian National Institute of Virology has identified eight mutations within the spike protein of the Delta variant (B.1.617). Two of them have been linked to higher rates of transmission and one of them, as with the Gamma variant, has even been associated with immune escape, which enables the pathogens to evade the human immune system.

According to London's Imperial College, the Delta variant is 20 percent to 80 percent more transmissible than the Alpha variant. In addition, the virus may be able to evade immunity conferred by previous infections or vaccination. British studies indicate that existing BioNtech-Pfizer and AstraZeneca vaccines are not as effective when it comes to protecting us from this variant.  

The variant discovered in Vietnam is a hybrid of the Alpha (B.1.1.7) and Delta (B.1.617) variants. Only one million of the 96-million-strong population have been vaccinated with AstraZeneca, which protects well against the Alpha variant, but, as mentioned above, is probably not as effective against the Delta variant. In the second half of the year, Vietnam hopes to receive additional mRNA vaccines from BioNtech-Pfizer and Moderna. So far, however, it has not been investigated how any existing vaccines cope with the variant discovered in Vietnam. 

In Bangladesh, by contrast, the Beta variant (B.1.351) has sparked a rapid rise in cases. AstraZeneca has been reported as offering "minimal" protection against this strain. This is a big problem, as the main vaccine available in Bangladesh is Covishield, the name for AstraZeneca manufactured in India.

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Unfair global distribution of vaccines

While many industrialised nations aim to have vaccinated the majority of their adult population by late summer, many poorer Asian, African, or Latin American countries have not even been able to launch their vaccination campaigns.

According to a recent study in the medical journal The Lancet, the world's richest countries have secured some 70 percent of supplies of the five top COVID vaccines despite having less than 16 percent of the globe's population. According to the WHO, only 0.2 percent of the population in poorer countries have been vaccinated against SARS-COV2. The Economist estimates that mass vaccinations will not start there until 2024 at the earliest if programmes continue at this pace.

The initiative COVAX, co-organised by the WHO, is meant to work toward more equitable access to COVID-19 vaccines. But from the outset, richer countries have signed simultaneous bilateral contracts with several vaccine manufacturers and — apart from a few generous donations — swept the market clean.

"The pandemic is far from over," WHO Director-General Tedros Adhanom Ghebreyesus has warned. He has vehemently criticised the huge inequality in the distribution of vaccines between poor and rich countries.

But, if the coronavirus variants continue to spread as rapidly as they are and to adapt to their human hosts, that inequality could come home to roost for wealthier nations.

(This article by author Alexander Freund was originally published on Deutsche Welle.)