Thiruvananthapuram, Jan 19

Efficacy of the Covid-19 vaccine will always be challenged and compromised as the Coronavirus keeps evolving with immune escape capabilities. The vaccine platform will require constant modifications if it must provide immunity against new variants.

Currently, the Omicron variant is found to escape all vaccine-induced immunity and pharma companies are reformulating vaccines to make it effective against not just Omicron but also other variants, points out Dr Satish Ranjan, leading Germany-based immunologist.

Big bang reforms needed

“This is an extremely tedious work and requires huge resources. It would also tell on the economics of an immunisation programme that a country such as India needs for its vast population,” Ranjan told BusinessLine. Globally this drive needs to be continuous, sustainable and affordable. 

Since vaccine development would be expensive and its efficacy likely short-lived, India should bring big-bang reforms in healthcare and evolve a two-pronged strategy that addresses a potential future pandemic and gives allowance to other infectious and non-infectious diseases as well.

The country needs to develop a structured, integrated, preventive and responsive healthcare system wherein all private and public healthcare infrastructure are governed by a unified law. “We need to learn lessons from the current pandemic and formulate a national pandemic prevention programme,” he added.

Seven coronaviruses in all

Ranjan recalled how the term Coronavirus was coined in 1968 for a group of viruses with crown-like structures and which resembled the solar corona under an electron microscope. These viruses were responsible for causing common cold in humans and bronchitis and intestinal diseases in animals.

Seven coronaviruses are now known to infect humans; of them, four cause common cough and cold and have the ability to primarily infect upper respiratory tract only, Ranjan explained.

Two others, namely SARS-CoV-1 (Severe Acute Respiratory Syndrome) and MERS-CoV (Middle East Respiratory Syndrome) infect lungs and can cause severe diseases. The last one in the series, SARS-CoV-2, has triggered the current pandemic and causative agent of Covid-19.

Genomic proofreading ability

SARS-CoV-2 has unique ability to infect both the upper respiratory tract and lungs and causes severe diseases that have claimed millions of lives globally. Coronaviruses are also one of few RNA viruses with genomic proofreading mechanisms that prevent unfavorable mutations deleterious for their existence.

SARS-CoV-2 also possesses this ability and many antivirals that can induce unfavorable mutations in hepatitis C and other viruses have failed to induce unfavorable mutations with it. 

“Instead, it has undergone favorable mutations with enhanced infectivity and immune escape abilities. It is likely that it may survive for long, become endemic and we have to learn to live with it,” Ranjan said. 

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