Kerala has entered an uncertain phase of the pandemic, with the Delta virus variant sweeping across the State, undeterred by the prior immunity in the population derived from infection due to the original virus (before it mutated to Delta) or the immunity rendered through vaccination.
The State continues to report a daily caseload of 20-22,000 new COVID-19 cases, even as it has delivered over two crore first dose vaccines to the population above 18 years.
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The arrival of Delta, which has been the single driver of disease transmission in the State since mid-May, has drastically changed the pandemic scenario. With a good number of re-infections and breakthrough infections adding to the daily caseload of the state, it is becoming increasingly clear that vaccinating our way out of the pandemic may not be an option.
“Vaccination, we thought, will get us out of the pandemic and that the herd immunity thus achieved will keep us safe from disease and help us return to normality. But with Delta forcing us to shift the vaccination thresholds constantly, herd immunity as far as COVID is concerned, is an elusive target. Because Delta virus is an immune escape variant, despite vaccination, we will continue to have a certain level of disease transmission and a steady case load. We will have to tolerate this for a long period. The options remaining with us are to concentrate on reducing hospitalizations and deaths,” says E. Sreekumar, senior scientist at Rajiv Gandhi Centre for Biotechnology (RGCB).
Israel, which has one of the highest levels of vaccination in the world, is now in the process of administering a third booster dose to all those above 50 years as the surge in Delta has resulted in high levels of hospitalisation, with more than half the cases in fully vaccinated individuals.
“For all practical purposes, Delta is a new virus which has arrived on the scene and every person who has had prior exposure to the earlier virus and those who have been currently vaccinated, continue to be susceptible to this new virus. Delta transmission will be maintained at a low level in the community till the virus has run through the entire population,” Dr. Sreekumar says.
The fact that a significant proportion of the State’s population is still immunologically naive means that this is going to be a prolonged process.
Kerala’s current situation of rising cases and high test positivity rate, in comparison to the rest of India can be assessed only by studying the granular data from every district – what is the proportion of the population getting re-infections or the infection after taking the first dose/ second dose of vaccine ?
What is the proportion of people who developed serious disease and were hospitalised after re-infections / the first/second dose of vaccine? Are deaths happening among the fully vaccinated in the State and most importantly, are there avoidable deaths?
According to the Government, re-infections are less in Kerala. So does that mean that those who were infected by the original strain of the virus have more immunity than the vaccinated population?
“The Government has not been willing to open up this data to its own experts’ committee on COVID for analysis, despite repeated requests. At this point in the pandemic, it is important that this data is analysed as soon as possible so that science-based strategies can be adopted,” a member of the experts’ committee says.
It is important to know how far re-infections and breakthrough infections are contributing to the State’s case load and the relative role of these in sustaining disease transmission in the community.
The State can, for example, take a few panchayats where there has been high coverage of vaccination and study the transmission pattern there, he suggests.
Strategies like contact tracing and containment zones are effective when a virus is first introduced into the community. When the virus continuously evolves, strategies would also have to be changed so that the virus does not get the upper hand.
While vaccination will not prevent individuals from getting infected or from transmitting the disease, it will certainly protect them from serious disease, studies show. Breakthrough infections should be expected but what is more important is to track with genomic sequencing, whether any new virus variants are emerging.
Instead of blindly going by the book, Kerala should be taking stock of the current situation and re-assessing its strategies, in order to move forward .
While containment strategies cannot be totally given up, mitigation has to go hand in hand as lives and livelihood have to be saved. The process of unlock will have to go forward but when it comes to festivities, multiple families gathering together and increased social interactions can open up new chains of disease transmission, about which the community has to be made aware.
