DELTA VARIANT COVID-19

All viruses change to adapt and survive the adverse conditions and mutants or variants emerge when a strain has one or more mutations that differ from others. Delta variant or B.1617.2 is a mutated SARS coronavirus, first detected in India in 2020. World Health Organization (WHO) named it as Delta in May 2020. By early June 2021, it had spread to 62 countries and by 4th July the Delta variant spread to 104 countries in the world. The Delta variant of COVID-19 is now the dominant strain worldwide. The countries affected include US, UK, most countries in the EU, Kazakhstan, Laos, Latvia, Lebanon, Namibia, Oman, Russia, Malaysia, Indonesia, Vietnam, Brazil,South Africa and so on.

In the UK the delta variant first started in the north, and then it spread all over the country in an alarming way. Today (16/07/2021) there are over 50000 new cases in the UK and the government is criticised for not closing the border for Indians in   April once it was spreading there like wildfire, killing tens of thousands of people. Epidemiologists and experts predict a devastating third wave in autumn, and asked the government not to relax lockdown restrictions altogether. In the US, delta variant is predominantly seen in Iowa, Kansas, Missouri, and Nebraska.

There is a Delta plus variant, first identified in Maharashtra, India known as B.1.617.2.1 or AY.1 which is a subvariant of the delta version. This variant is better equipped to attack alveoli in the lung. As the delta viruses are spreading exponentially, we can expect more mutations. We have seen a successful small pox vaccination harnessing the mutation of smallpox virus. Same is the case with most viruses including SARS coronavirus.

Normally the classic symptoms of Covid are incessant dry cough, fever, headache,loss of smell and taste, malaise and breathlessness. But in Covid due to Delta variant, the symptoms are headache, runny nose and sore throat. However , headaches have been a common symptom regardless of variant. Delta variant is four times more capable of overpowering protective antibodies in the host than Alpha variant. People who have had Covid previously are more likely to be reinfected with delta variant. Lateral flow test followed by PCR test will help to diagnose delta variant.

Delta variant is notorious for its capability to transmit to others. Each infected person is capable of infecting seven other people, by contrast the original strain of Covid-19 infects three more, while Kent or Alpha is capable of transmitting to four to five more people. Delta has a key mutation on the spike protein which it uses to attach on to human cells. This spike protein is called L452R which is responsible for transmission between infected and uninfected person within a shorter period. Both Astra Zenecca and Pfizer-Biontec vaccines help to reduce transmission and hospitalisation.

It is established that single vaccination does not help much but with double vaccination, the protection is far greater. Generally, those who have had two vaccinations, 88% in Alpha and 80% in Delta variant infections are covered. Recently in the UK, it has been reported that 50% over 50 years and 40% of those who are between 19 and 49 years are likely to get damage to kidney, liver and fibrosis of lung in the acute phase of Delta infection, which is not classed as ‘long covid’. Double vaccination significantly reduces hospitalisation and death due to delta variant. Even with one dose of the vaccine, 75% people are protected from hospital admission. This rises to 92 and 94 per cent with both doses of vaccination. If initial symptoms are considered, one dose of vaccine is 49 per cent effective at preventing symptomatic infection for the Alpha variant, and 31 per cent effective for the delta variant. For our consolation the case fatality rate for Delta variant is very low at 0.3% compared to 1.95% for Alpha variant. Remember how shockingly bad was the death rate early this year.

Death after double vaccination is very rare. A recent study by Indian Council for Medical Research (ICMR) shows that only 3 double vaccinated patients died after getting infected with delta variant. So far over 300 million people in India are double vaccinated, and therefore the rate of fatality for vaccinated people is next to nothing. Benefits of taking doses of vaccine is very prudent and it outweighs the risks from taking the vaccination. Taking double vaccination is very beneficial particularly for preventing the spread of Delta variant, the UK government should make vaccination mandatory to safeguard the community.