Delta Variant is the SARS-CoV-2 variant first detected in India; technically called the B.1.617.2. The World Health Organisation (WHO) has already declared it a variant of concern (VoC). Its two other less worrying variant are also first identified in India. They are B.1.617.1 and B.1.617.3.
Why is the delta strain so concerning?
The Delta strain is considered much more contagious than the UK variant (alpha variant or B.1.1.7), which is itself much more transmissible than the original SARS-CoV-2 strain. Dr Neil Ferguson, an epidemiologist at the Imperial College London (ICL) says that the delta variant is 40-80 per cent more transmissible than the alpha variant. However, Public Health England (PHE) asserts that it is 60 per cent more transmissible than the alpha variant (B.1.1.7) as published in The Telegraph on June 11, 2021.
One can imagine how contagious the delta strain will be, considering the fact that the alpha variant is itself 50 per cent more transmissible than the original Wuhan strain of the Coronavirus that is causing the global pandemic of COVID-19.
Prof Ferguson calculated that if there were no restrictions in place including no vaccinations, the delta variant's basic reproduction number, R0 would be between five and eight. You may compare this with the R0 value of about three for the original strain and between four and five of the alpha variant.
The delta strain has now spread to more than 60 countries in the world. It is already the predominant strain in the UK and India. It is threatening new outbreaks in Asian nations such as Taiwan, Singapore, and Hong Kong. US President Joe Biden also warned that the delta variant may become the predominant coronavirus strain in the US by July-end.
In the UK, about 90 per cent of new cases are now possibly due to the delta variant, and public health authorities are, now, fearing the rise of a new COVID wave in the United Kingdom and is considering to postpone the planned easing of lockdown starting with June 21, 2021. Please note that such stringent caution is being considered in a country that is already more than 40 per cent fully vaccinated (the fully vaccinated ratio in India is still less than 5 per cent).
Why is the delta variant so contagious?
The delta variant has a crucial mutation in the spike protein called L452R, which facilitates the entry of the coronavirus into human cells. Prof Wendy Barclay of ICL says that the variant seems "fitter" than other variants. The variant can spread much more easily in an infected person's airways. She also believes that shorter exposure time may be needed between two people for the virus to spread.
The delta variant has T478K, D614G and several other mutations; some of which make it more resistant to COVID vaccines, i.e. vaccine's capacity to protect will be less in patients infected with delta compared to those infected with other variants.
Is the variant causing more severe COVID disease?
Another associated worry is whether the delta variant is causing more severe COVID disease. Preliminary data seems to indicate so. Doctors in several parts of India are now reporting a host of clinical indications not seen in the first wave of the COVID-19 pandemic in the country. These include hearing loss, gastrointestinal upsets including severe diarrhea and clots in blood vessels that may lead to gangrene of the affected tissues (Times of India, June 12, 2021). Early data in England and Scotland indicate that the delta variant is also associated with higher risk of hospitalizations.
Dr Abdul Ghafur, Apollo Hospital, Chennai says that he is now seeing more COVID patients with diarrhea than in the first wave of the pandemic. Stomach pain, nausea, vomiting, loss of appetite, hearing loss, and joint pain are some of the atypical indications that are reported in the second wave patients across India.
Another complication, according to Dr Ganesh Manudhane, Seven Hills Hospital, Mumbai is formation of blood clots that may lead to the death of the affected tissues e.g. fingers or feet. Manudhane has treated many patients with thrombotic complications probably associated with the delta variant, two of which had to undergo amputations of fingers or feet. Some Covid patients are also suffering from hearing loss, as reported by Dr Hetal Marfatia, King Edward Memorial Hospital, Mumbai.
Dr Raina MacIntyre, University of New South Wales, Sydney says that there was a fourth lockdown in Melbourne, Australia due to unusual complications in Covid-19 patients possibly associated with the delta variant (B.1.617.2) and its relative called kappa variant (B.1.617.1).
Delta variant in the United States
The delta variant currently accounts for about six per cent of infections, though in some states it accounts for more than 18 per cent of the COVID samples cases, according to CDC USA (Gabriela Miranda, USA Today, June 11, 2021). Dr Bhakti Hansoti, Johns Hopkins University, opines that delta variant is associated with more severe symptoms of Covid. He says that doctors in the United States have seen more cases of hearing loss, severe stomach pains and nausea in patients infected with the new variant. Patients infected with delta variant are more likely to be hospitalised, require oxygen therapy, and suffer from other serious complications.
Why is the second dose of vaccine so essential?
A study by Public Health England (PHE) reported that two doses of the Pfizer vaccine was 88 per cent effective against symptomatic diseases caused by the delta variant but the protection was reduced to just 33 per cent after a single jab (discussed in detail in earlier column). The corresponding figures for the AstraZeneca vaccine (CoviShield in India) was 60 per cent (after 2 jabs) and 33 per cent (after a single shot). It is also known that protection by vaccines decline over age and time.
Therefore, in view of the increasing threat by the delta variant, it is urgently warranted to give second jabs to all eligible individuals especially elderly and co-morbid persons.
Dr Jonathan Baktari, CEO, e7 Health, a healthcare and wellness company, asserts that in view of the raging delta strain, it's very important to get both doses of the COVID vaccine.
Dr Baktari says that the delta variant is a stickier virus, if one infected person with this variant is in a room and (s)he talks or sneezes, the aerosol will release the coronavirus and it (delta strain) will find it easier to stick to another person, compared to other lineages of the virus.
What is to be done?
Even though the delta variant is partly resistant to most vaccines approved so far, vaccinations remain the most protective wall against the variants, including the delta strain. Seventy to eighty per cent of the population must be vaccinated (with two doses for most vaccines) to achieve the herd immunity. This amounts to vaccinating about 100 crore Indian population (about 200 vaccine doses), including about 24 lakh people in Manipur. Manipur today has vaccinated 4,64,465 people through the nationwide vaccination drive, while its tally of Covid-19 confirmed cases in the state reached 59,322 on Saturday.
However, India has administered less than four per cent of its population with two shots and less that 15 per cent with at least one shot.
So, in view of the delta variant and other variants likely to emerge soon, we need to ramp up the vaccination drive on war footing in India as well as Manipur.
Meanwhile, masking, non-pharmaceutical interventions such as masking, sanitization and distancing need to be followed for some more time. Large cultural or political or religious gatherings need to be strictly regulated. And, there is a need for close scrutiny in schools and public spaces where there may be congregations of symptomatic people (including those carrying the delta variant). At the same time, the pace of Covid testing, contact tracing, isolation of positive cases and treatment of serious patients need to be increased in a big way.
As of June 12, 2021, the number of new daily COVID-19 positive cases in India fell to less than one lakh cases, with the number of deaths per day ranging from 2000 to 3000. As new infections are sharply dropping, one can take this as a heartening development. However, there's a concerning aspect. A signification fraction of recovered patients, individuals who tested negative and discharged to recover at home is showing a slew of concerning post-COVID complications. These complications have been reported from Delhi, Mumbai and several other Indian cities and include herpes, hair fall, skin diseases, etc. (news18.com, June 9, 2021).
Dr D M Mahajan of Apollo Hospital, Delhi says that many patients affected by herpes in his hospital are contracting the disease for the first time, possibly linked to weakened immune system due to the coronavirus infections.
Some patients are also manifesting other symptoms such as hair loss and dermatological issues, including melanonychia-nails turning brown.
In addition, there are the challenges of mucormycosis (black fungus)-there are now more than 30,000 cases reported in India-, multisystem inflammatory syndrome in children (MIS-C), and brain fog, chronic fatigue syndrome, memory loss and other 'long Covid' complications that may erupt several weeks after recovery from COVID-19 disease.
Possible measures for Manipur
We need to assume that there may be a third COVID-19 wave in Manipur too. Even if that may turn out to be a wrong anticipation, it is better to err on the side of caution. Accordingly, we must initiate stringent safety measures to squarely face a possible third wave in our state, while continuing to contain the spread of the virus. Manipur on Saturday (June 12, 2021) reported 554 new daily COVID-19 positive cases and 15 more deaths.
Imphal West and Imphas East districts continued to report the highest number of cases with a total of 171 and 118 new positive cases respectively, according to the latest update by the state health department. It stated that The total number of recoveries reached 49,653 as 751 more patients, including those in home isolation, recovered in the last 24 hours. With it, the recovery rate moved up to 83.70 per cent. The total number of active cases now is 8710. The recovery rate on Friday was 83.21 per cent.
The preventive measures may include:
Speeding up Covid vaccinations across the state in a big way.
Genomic sequencing of a subset of positive cases and surveillance of the variants, including the delta variant: which COVID strains are there in Manipur, where are they, and where are they moving towards.
Boosting healthcare provisions such as medical oxygen plants, tankers and cylinders; steroids, antifungal drugs, oxygen concentrators, ventilators, oximeters, masks, PPEs, sanitizers etc.
Strengthening of healthcare infrastructure such as construction of new COVID hospitals in several parts of the state.
Provision of more COVID care centres (CCCs), more Covid beds and COVID ICUs in existing hospitals
Constitution of a special task force to tackle the third COVID wave; and a separate task force for pediatric COVID is also highly recommended.
Special provisions for kids such as pediatric hospitals, wards, and ICUs, pediatric oximeters, concentrators, and ventilators and strengthening of staff such as pediatricians and pediatric nurses and paramedical workers, etc.
As an editorial in the prestigious medical journal, The Lancet Microbe (Jan. 1, 2021) says, "Vaccines will be instrumental in the control of COVID-19, but their global distribution will be challenging and their effect won't be immediate." So, in the meantime, we must not let our guards down and we must still strictly observe the non-pharmaceutical interventions such as the major Standard Operating Procedures of the use of face masks, maintaining physical distancing, and hand hygiene and avoidance of 3 Cs: crowded places, close contact settings, and closed spaces (with poor ventilation). We must religiously follow the protocol of 'test, track, and treat' for months to come. If possible, the public health authorities must take steps to prevent large gatherings such as weddings and death ceremonies, music concerts, and large meetings.
The 'hoi polloi' must voluntarily practice the 3 Ws (watch your distance, wear your masks, wash your hands frequently) with soap and avoid the 3 Cs: crowded places, closed contact settings, and closed spaces.
Meanwhile, we must enhance the pace of vaccinations across India including Manipur in a big way.
In this intricate game of chess, humanity must be one step ahead of the wily virus!