SARS-COV-2 DELTA VARIANT AND DELTA PLUS VARIANT - SYMPTOMS, TREATMENT, & VACCINE EFFICACY

 

Experts believe that the Delta Plus variant has increased transmissibility but it is still not very clear as to how virulent this new strain is in comparison to other variants. Medical experts say it is too early to predict the effectiveness of the existing vaccines on the new variant. A detailed study would be required to establish any effect of the mutant on the immune system.

What is SARS-CoV-2 Delta variant?

·         It is also known as lineage B.1.617.2

·         It is a variant of lineage B.1.617 of SARS-CoV-2, the virus that causes COVID-19.

·         It was first detected in India in late 2020.

·         The World Health Organization (WHO) named it the Delta variant on 31 May 2021.

·         Public Health England (PHE) and WHO classified it as a variant of concern (VOC) based on an assessment of transmissibility.

·         It showed evidence of higher transmissibility and reduced neutralization.

·         The variant is thought to be partly responsible for India's second wave of the pandemic beginning in February 2021.

·         The Delta genome has 13 mutations.

·         Don’t get confused with the delta-coronavirus which mainly affects birds.

What is Delta Plus variant?

·         The new Delta plus variant has been formed due to a mutation in the Delta or B.1.617.2 variant.

·         It is a sub-lineage of the Delta variant .

·         Delta with K417N corresponds to lineages AY.1 and AY.2 is know as Delta Plus.

·         It has been nicknamed "Nepal variant".

·         It has the K417N mutation which is also present in the Beta variant.

·         As of June 16, at least 197 cases had been found from 11 countries — Britain (36), Canada (1), India (8), Japan (15), Nepal (3), Poland (9), Portugal (22), Russia (1), Switzerland (18), Turkey (1), the United States (83), India(40 cases in Maharashtra, Kerala and Madhya Pradesh).

·         No deaths were reported among the UK and Indian cases.

What are the symptoms of Delta and Delta Plus Variants?

·         Headaches,

·         A sore throat and

·         A runny nose

·         Fever.

What is the treatment?

The treatment for those infected by the SARS-CoV-2 Delta variant is as per others infected by COVID-19.

Are Vaccines effective against new variants?

·         The WHO has said current vaccines will continue to be effective against the variant. There may be some evidence of "reduced neutralization’. 

·         A study conducted by the Public Health England, has found that both Pfizer-BioNTech and AstraZeneca-Oxford vaccines provide a 33% protection against symptomatic disease caused by the variant after the first dose. Two weeks after the second dose the Pfizer-BioNTech vaccine was found to be 88% effective at stopping symptomatic disease from the Delta variant while the AstraZeneca-Oxford vaccine was 60% effective against the variant.

·         In June 2021, Public Health England announced it had conducted a study which found that after two shots, the Pfizer-BioNTech vaccine and the AstraZeneca vaccine are respectively 96% and 92% effective at preventing hospitalisation from the Delta variant.

·         ICMR found that convalescent sera of the COVID-19 cases and recipients of Bharat Biotech's BBV152 (Covaxin) were able to neutralise VUI B.1.617 although with a lower efficacy.

·         Another study by the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad found Covishield (Oxford–AstraZeneca) vaccinated sera offers protection against lineage B.1.617.

Covid-19 vaccines made by AstraZeneca and the Pfizer-BioNTec alliance remains broadly effective against Delta variant. However, it is not yet clear if the existing vaccines are effective against delta plus.

 

References:

1.       "Confirmed cases of COVID-19 variants identified in UK". www.gov.uk.

2.       "Expert reaction to cases of variant B.1.617 (the 'Indian variant') being investigated in the UK". Science Media Centre.

3.       "Covid: WHO renames UK and other variants with Greek letters". BBC News. 31 May 2021.

4.       "Confirmed cases of COVID-19 variants identified in UK". www.gov.uk. 7 May 2021.

5.       WHO labels a Covid strain in India as a 'variant of concern' — here's what we know, CNBC, 11 May 2021.

6.       "India's second COVID-19 wave", The Wire Science, 22 April 2021.

7.       The COVID-19 Delta Variant: Here's Everything You Need to Know (US publication Healthline)

8.       Yadav, PD; Sapkal, GN; Abraham, P; Ella, R; Deshpande, G; Patil, DY; et al. (7 May 2021). "Neutralization of variant under investigation B.1.617 with sera of BBV152 vaccinees". Clinical Infectious Diseases. doi:10.1093/cid/ciab411. PMID 33961693

9.       "Covishield Covaxin effective against 'Indian strain' of coronavirus study suggests". The Week. Retrieved 27 April 2021.

10.   "Vaccines highly effective against hospitalisation from Delta variant". www.gov.uk. Public Health England. 14 June 2021. This article contains OGL licensed text This article incorporates text published under the British Open Government Licence v3.0:

11.   "UK study finds vaccines offer high protection against hospitalisation from Delta variant". Reuters. 14 June 2021.