Viruses mutate to survive. This is what they do all the time. SARS-CoV-2, or Sars-2 has undergone several mutations giving rise to a number of variants. Delta variant, detected first in India and named so by the World Health Organisation (WHO), is now a Sars-2 variant of global concern. Studies showed that the Delta variant was behind the second wave of Covid-19 pandemic in India. But India has a new worry, another mutant variant, the Delta Plus.
WHAT IS DELTA PLUS?
It is the gen-next of the Sars-2 coronavirus -- a mutant of the Delta version. The Delta Plus variant is technically named B.1.617.2.1 or AY.1.
While the Delta variant was first discovered in India last year and has made health authorities nervous in Europe and elsewhere, the Delta Plus variant was detected first in Europe in March this year and is giving chills to authorities in India.
Genome sequencing for Sars-2 variants have been done at a breakneck speed across the world. Still, the virus and the disease it causes remain a mystery, unexplained in many aspects. This is where it creates greater fear than other pathogens.
Speaking to India Today TV, top virologist Shahid Jameel warned that the Delta Plus variant may defeat vaccines, antibodies and infection-induced immunity against Sars-2.
WHY IT MATTERS FOR INDIA
The second wave, understood to have been caused by the Delta variant, is in retreat in India. Over 90 per cent districts show a receding trend for Covid-19.
There is a concern among scientists that the Delta Plus variant could be even more transmissible than the Delta variant.
Over 20 cases of Delta Plus infection have been reported from Maharashtra at a time when experts are warning that India may see a third wave of Covid-19 pandemic soon.
The pace at which the Delta variant triggered the tsunami of Covid-19 cases through April and May only a few months after it was first detected makes its mutant version, the Delta Plus, a bigger threat, at least theoretically.
NOW, LET's UNDERSTAND THE DELTA VARIANT
It was first detected in samples isolated from Maharashtra in December 2020. Identified as B.1.617.2 or the second version of Sars-2 mutant B.1.617, it was named Delta variant by the WHO in May.
According to the WHO, the Delta variant has now been reported from about 75 countries. In countries such as the UK, it has emerged as the most dominant variant of Sars-2.
In the US, the Delta variant has shown a sharp spike in spread from about 10 per cent to over 30 per cent in the past one week.
WHY IS THE DELTA VARIANT SO DANGEROUS?
The Delta variant is making the whole world nervous as it has been found to be more transmissible compared to the Alpha variant whose detection in the UK had made global headlines last year.
The Alpha variant was considered 43-90 per cent more transmissible than the pre-existing variants of Sars-2. Experts say the Delta variant is 40 per cent more transmissible than the Alpha variant.
However, this MIT publication claimed that the Delta variant could be up to 100 per cent more transmissible compared to the Alpha variant of Sars-2.
DOES THE DELTA VARIANT CAUSE DIFFERENT SYMPTOMS?
Experts are saying that the Delta variant is causing clusters of symptoms that were not previously associated with Sars-2 infection. According to the Gavi Vaccine Alliance, the Delta variant is making patients become sicker and their condition deteriorate faster than in cases of infections caused by previous variants.
According to the Gavi alliance, progression of symptoms in Delta variant infection cases goes like this: headache, followed by sore throat, a runny nose, and fever. Cough is less common and loss of smell is also not common.
IS THE HOSPITALISATION RATE HIGHER IN DELTA CASES?
Pandemic experts are of the view that the Delta variant may be associated with greater risk of hospitalisation of Covid-19 patients.
According to a Scottish study that was published in The Lancet on June 14, the Delta variant posed almost twice the risk of hospitalisation compared to the Alpha variant.
CAN DELTA VARIANT EVADE VACCINES?
American doctor and epidemic expert Eric Feigl-Ding raised concern about efficacy of vaccines against the Delta variant. He said AstraZeneca's vaccine, called Covishield in India, could be 60 per cent effective at best against the Delta variant.
The Lancet study referred above also suggested that vaccines are less effective against the Delta variant particularly with one dose.
Even in the case of two doses, the efficacy of Pfizer-BioNTech's vaccine reduces, according to the study, from 92 per cent against the Alpha variant to 79 per cent against the Delta variant.
DOES DELTA PLUS POSE THE SAME THREAT?
Clear scientific evidence is lacking. But as the rule of biology goes, every successful mutation makes a virus more adept to survive.
Simply put, if Delta Plus turns out to be a successful mutation over the Delta variant, it can retain all threatening attributes of the Delta variant - further increased transmissibility, more severe illnesses meaning more hospitalisation, greater resistance to medicines and wider escape from available Covid-19 vaccines.
Cases of Delta Plus infection are being studied closely and the progression of Covid-19 among such patients is being recorded minutely to understand it better. Only data and scientific evidence can paint a clearer picture
Source: India Today | June 23, 2021