Even as Odisha has been home to around 158 Covid-19 variants, it's the Delta variant that has triggered the second wave in the State. The variant has dominated in nearly 85 per cent of the samples sequenced for the genome in the State. The big concern is behavioural studies by Public Health England reveal a higher re-infection chance by the Delta variant.
Moreover, when India has reported 6 cases of its upgraded version Delta-Ay.1 or Delta+, the Public Health England study finds that of the 36 cases reported globally, 27 have a vaccinated status.
The big revelation is a majority of the Delta+ positives across the globe belong to the younger age group. Only 2 belong to 60+ age group. But the respite is fatality is zero.
Known the world over as a variant of concern, the Delta variant is considered a big concern for the schools in the State - mainly because children are yet to be vaccinated. Moreover, when it's early main symptoms now are only headaches, sore throat, runny nose, and no fever. The concern is many children can gloss over it as a bad cold. And late testing could have serious repercussions on the life of the patient, studies reveal.
As per the data with INSACOG (Indian SARS-CoV-2 Genomics Consortium), the Covid-19 variant of concerns detected in the State have been Delta, Alpha (UK variant) and the earlier variants like N440k. Delta not only triggered the second wave, but it has also dominated the State's Covid map entirely. The moot point is how Delta, a late entrant into the State, dominated the scene in a big way?
Reasons Behind High Delta Infection
A recent technical analysis of the variant behaviour by Public Health England, UK has shed light on the factors that give the mutant virus an edge to dominate in the second wave of the pandemic. The details are given below.
- In comparison to Alpha (UK variant), the transmission of the variant has been 60 per cent more.
- The growth rate, which reflects how quickly the numbers of infections are changing day by day, and when its size indicates the speed of change, the UK variant behaviour study shows Delta variant has the highest growth rate among all the variants of concern.
- Before lockdown, the doubling rate in India, as per Union Health ministry data, has been 3.4 days.
Why A Concern For Schools?
The virus behaviour study by Public Health England shows that when a vaccinated individual has only a 10 per cent chance of falling ill. The number in the unvaccinated stood at over 95 per cent - means unvaccinated have 95 per cent chances of showing Covid-19 symptoms. And a higher probability of hospitalisation.
- As children below the age group of 18 years are unvaccinated, the Delta variant is considered as the mega risk factor in triggering the third wave.
- Delta variant triggered the majority of infections in schools in London.
How Majority Having No Travel History Infected?
As per the study by UK Public Health, the secondary attack by this variant is highest among all the variants of concern present globally.
Secondary attack means the transmission of the virus to contacts - who either have travel history or not having any such.
- The study finds that the secondary attack rate among contacts of cases that have travelled has been 2.4 per cent.
- However, the attack rate among contact cases that have not travelled or unknown has been higher at 11.3 per cent.
How Is Entire Household Get Infected?
As per the study, the secondary attack rate for the variant is high in household contacts than in non-household contacts.
- It has estimated the rate at 12.3 per cent among household contacts that have not travelled vis-a-vis a rate of 6.3 per cent among non-household contacts of cases that have not travelled or unknown.
Simply put, Delta variant transmission is higher among people who have no travel history. Also, a single infection in a family holds the potential of infecting the whole family, the variant behaviour study suggests.