Decoded: How Delta variant, first found in India, is spreading across globe

After wreaking havoc in India during the deadly second wave of the Covid-19 pandemic in April and May, the Delta variant has now spread to more than 90 countries -- from the US to Europe to Africa to Australia.

According to the Union government, 90 per cent of the Covid cases in India are being driven by the B16172 (Delta) variant.

The Delta variant was first detected in India in October 2020, and has rapidly surpassed the other strains since then to become the most transmissible variant of Covid, according to the World Health Organization (WHO). In May, the global health body had declared it as a "variant of global concern".

 

"Delta has now spread to 92 countries," said Maria Van Kerkhove, the WHO's technical lead for Covid, CNBC reported.

US top infectious disease expert Anthony Fauci said earlier this week that the Delta variant is a growing threat and is more transmissible than the original Covid virus and Alpha variant.

"The transmissibility is unquestionably greater than the wild-type SARS-CoV-2, as well as the Alpha variant. It is associated with an increased disease severity, as reflected by hospitalisation risk, compared to Alpha. And in lab tests, it is associated with modest decreased neutralisation by sera from previously infected and vaccinated individuals," Fauci said at a White House briefing.

The variant has infected about 50 per cent of vaccinated adults in Israel, forcing the country to re-impose the mandate to wear a face mask indoors. The mandate was lifted on June 15, following one of the world' fastest successful vaccine roll out programme in Israel.

Also, 90 per cent of the new infections in the country are caused by the Delta variant, the Wall Street Journal reported.

"The entrance of the Delta variant has changed the transmission dynamics," WSJ quoted Ran Balicer, who leads an expert advisory panel on Covid-19 for the Israeli government, as saying on Friday.

Australia has extended the Sydney lockdown as the city confirmed more than 80 cases of the highly infectious Delta variant in recent days.

Further, in the US, the variant accounts for more than 20 per cent of cases, and is soon set to become the dominant variant in the country.

Based on "mounting evidence" of the Delta variant being more transmissible, the US Centers for Disease Control and Prevention declared it as a variant of concern on June 15.

Last week, the UK had 35,204 new cases of the Delta variant -- a 46 per cent increase -- the Public Health England (PHE) said on Friday. The variant now comprises 95 per cent of all sequenced cases in the UK, PHE added.

It has also forced the government to delay the full reopening of the society it had originally slated for June 21.

Delta poses the biggest risk to countries with limited access to vaccines, such as Africa -- currently facing a fast-surging third wave of the Covid pandemic.

Globally, around 2.7 billion vaccine doses have been administered, of which just under 1.5 per cent have been administered in Africa. Across the continent, the Delta variant has been reported in 14 countries, the WHO said.

The Mayor of Moscow, Sergei Sobyanin, has said that the Delta variant represents nearly 90 per cent of the new cases in the Russian capital. The country logged 20,182 new coronavirus infections over the past 24 hours, the highest daily increase in the last five months.

Other countries facing the attack of Delta variant include Singapore, Fiji Islands, Indonesia, France and Portugal.

Meanwhile, the Pfizer-BioNTech and Oxford-AstraZeneca vaccines have been found effective against the Delta variant. The Pfizer-BioNTech vaccine has been found 96 per cent effective against hospitalisation after two doses, while the Oxford-AstraZeneca vaccine is 92 per cent effective against hospitalisation after two doses, according to the PHE.

Covishield and Covaxin also work against the Delta variant, while their effectiveness against the Delta+ variant is being tested, Director General of Indian Council for Medical Research (ICMR), Balram Bhargava, said on Saturday.

The Delta+ (AY.1 sub lineage) variant mutated from the Delta variant and is thought to be more transmissible than the original variant.

As of June 16, at least 197 cases of the Delta+ variant were found in 11 countries -- Britain (36), Canada (1), India (8), Japan (15), Nepal (3), Poland (9), Portugal (22), Russia (1), Switzerland (18), Turkey (1), and the US (83).

In India, over 40 cases of the Delta+ variant have been detected sporadically in Maharashtra, Kerala and Madhya Pradesh, the Union Health Ministry said.

--IANS

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