The Delta Plus variant, a variant of concern, has already been identified in 11 countries and 12 states in India. It is the mutated form of the Delta variant of Covid-19 which was first detected in India. This variant is concerning since it spreads more rapidly than the other Covid-19 variants India has witnessed. It shows a greater affinity towards lung cells. Reportedly Delta Plus also has the ability to fight some vaccines and therapies being offered in various countries. But it has to be studied in the Indian context to know whether or not vaccines available in India will be effective against Delta Plus.
The Indian Council of Medical Research (ICMR) and the National Institute of Virology (NIV) have decided to carry out a study to check if Delta Plus can be neutralised by the vaccines present in India.
The highest number of cases is being seen in Maharashtra, Madhya Pradesh, and Kerala. Thus, the states are planning to tighten Covid restrictions. As per the data provided to the Centre by the ICMR, 48 cases of Delta Plus have been identified from over 45,000 samples collected during April, May, and June. The ICMR also mentioned that the Delta variant is very localised in India, and it has been isolated and cultured at the NIV in Pune.
Top doctors Dr Navin Kumar, Consultant Clinical Microbiology and Head of Laboratory services, HCMCT Manipal Hospital New Delhi; Dr Rajeev Boudhankar, Internal Medicine (MD) & CEO, Bhatia Hospital, Mumbai; Dr Shuchin Bajaj, Internal Medicine (Founder Director), Ujala Cygnus Group of Hospitals; Dr Arunesh Kumar, HOD, Paras Chest Institute & Sr. Pulmonologist, Paras Hospital, Gurugram; and Dr Piyush Goel, Senior Consultant- Pulmonary and Critical Care, Columbia Asia Hospital, Palam Vihar, Gurugram answer some queries related to Delta Plus variant.
Excerpts:
Q. What is the difference between Delta and Delta Plus variant?
Dr Rajeev Boudhankar: Delta Plus is a sub-lineage of the Delta variant first detected in India, which has acquired the spike protein mutation called K417N. There is a high chance that the mutation could make it more transmissible.
Q. How harmful can the Delta Plus variant prove to be in comparison to the earlier Covid-19 variants?
Dr Navin Kumar: The Delta Plus variant has stronger binding to receptors in the lungs but it does not signify that it has increased transmissibility and causes more severe disease. At present, there is a limited number of cases localised in few districts of the country. We need to closely monitor its spread to know more about its transmission ability.
Q. Are there any symptoms that can be specifically seen amongst patients infected by this Delta variant?
Dr Navin Kumar: The clinical symptoms are similar to other variants and available evidence suggests that it does not cause more severity. At present, the number of cases is less and we need more scientific data to understand its future potential.
Q. Why is the Delta Plus variant being called a ‘variant of concern’?
Dr Arunesh Kumar: Delta Plus variant has been instrumental in causing a new wave of Covid pandemic in the UK and parts of the US. This is a virus of concern because of its high infectivity and can cause severe disease. There are concerns that it can bypass vaccine immunity a phenomenon called immune escape. A country like India with big population size is always at risk of having an extensive effect. This strain is likely to cause the third wave. It is therefore important that people follow Covid appropriate behaviour.
Dr Shuchin Bajaj: The Delta Plus variant is a variant of concern because of a few reasons. One is the increased infectivity, which is much more than the previous one, the second is increased binding to lung cells, which may give rise to more severe disease, and the third is a potentially reduced response to monoclonal antibodies, which may interfere with the vaccine response as well as medicines like the monoclonal antibody cocktail, as well as previous infections. So, even previously infected or vaccinated individuals may suffer from the disease, as well as the fact that monoclonal antibody cocktail may be less effective against the Delta Plus variant. Due to all these reasons, there is a definite risk that the new Delta Plus variant will be more widespread as well as more severe if it causes the third wave.
Q. What are your views regarding the efficacy of the vaccines available in India on this Delta variant?
Dr Rajeev Boudhankar: Multiple studies are ongoing in India and globally to test the effectiveness of vaccines against the Delta Plus Covid-19 mutation. However, some virologists of the Indian Sars-CoV-2 Genomic Consortia (INSACOG), have recently expressed concerns regarding the Delta Plus variant. They believe that the new mutant variant may just be capable of dodging immunities, both from Covid-19 vaccines as well as from earlier infections. This is because the Delta Plus variant not only has all the symptoms that the original Delta variant had but also carries symptoms from its partner Beta variant (K417N mutation). The South African Government had returned a consignment of AstraZeneca (named Covishield in India) vaccines in the recent past as it discovered that in South Africa the Beta variant evades Covid-19 vaccines much better than the Alpha or the Delta variants. This raises a red flag. But the hypothesis that “Delta Plus variant could dodge Indian Covishield vaccine” still needs studying in the Indian context. However, the Indian Government, on the other hand, has quoted studies stating that the Covishield and Covaxin are ‘broadly effective’ on the Delta Plus variant. Further studies are required in this area to properly ascertain these claims.
Dr Navin Kumar: The Delta variant which is a variant of concern with 15 to 17 mutations was first reported in October 2020. The data suggest that both vaccines Covishield and Covaxin work against the delta variant of SARS CoV2 with a slight reduction in neutralising antibody response. The Delta Plus variant has the potential to escape our immune response. We need laboratory and more clinical evidence to know the efficacy of vaccines against Delta Plus variant.
Q. Why has the Delta Plus variant become a matter of concern in India & abroad?
Dr Rajeev Boudhankar: The mutation K417N has been of interest as it is present in the Beta variant (B.1.351 lineage), which was reported to have immune evasion property.
Some virologists have claimed that the K417N was known to reduce the effectiveness of a cocktail of therapeutic monoclonal antibodies.
As of 16 June 2021, 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).
As of 26 June 2021, the first death due to Delta Plus variant has been reported in India of an 80-year-old female, whose oxygen saturation fell down drastically. Index cases of the Delta Plus variant need to be traced and tracked for their health status.
WHO is tracking this variant as part of the Delta variant, as it is doing for other Variants of Concern with additional mutations. The WHO says, as of now, this variant does not seem to be common, currently accounting for only a small fraction of the Delta sequences. Delta and other circulating Variants of Concern remain a higher public health risk as they have demonstrated increases in transmission.
There are worries in the scientific community that the Delta Plus variant would inflict another wave of infections on India after it emerged from the world’s worst surge in cases.
While the earlier version had largely been blamed for the second wave of the coronavirus pandemic in India, the new, more virulent Delta Plus variant is being feared ahead of a potential third wave.
The emergence of the Delta and Delta Plus variants of the Covid-19 has once again put India and by extension the world in a state of high alert. Delta Plus, reportedly a variant with increased transmissibility, is the latest in a long list of new mutant forms of the Delta Covid-19 strain which was first detected in India. With the Delta Plus Covid-19 variant being detected in as many as 11 countries so far, it is a concern for the entire world.
Q. What can be the way forward in tackling this Delta variant?
Dr Piyush Goel: As more than two dozen cases have been detected in three states of Madhya Pradesh, Kerala, and Maharashtra, the Delta Plus variant of coronavirus is surely a cause of concern now. On 14 June, the World Health Organisation classified the variant ‘Delta’ and the offshoots — AY.1 and AY.2 — Variant of Concern. Considering the impending third wave of Covid-19, it becomes important to strictly follow the directions of the Health Ministry to engage in immediate containment measures. Large-scale vaccination drives and their tracking must be facilitated along with testing in districts and affected clusters. This must be done to ensure that “adequate samples” of positive persons be speedily sent to designated laboratories of INSACOG to conclude the clinical epidemiological correlations.
