Evidence of immunity is a glimmer, but data show lasting Covid-19 damage

Dr Guleria, who heads the clinical research group of the national Covid-19 task force, said that medical examination of patients with severe illness showed that even months after recovery, their lungs continued to be in “bad shape”, and they required oxygen at home.

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Covid-19 patients were now suffering from strokes and neurological disorders, making the disease worse than just a respiratory infection, Dr Guleria, the country’s top pulmonologist, said.

“First we thought it was only pneumonia, and then we realised it caused hypercoagulable state, which promotes clotting; and people were suddenly dying because of clots blocking blood vessels in the lungs and heart. And now we have also started seeing that it is happening in the brain, and people who presenting with stroke and other neurological problems. At the beginning, we thought all this not to be a big issue, but as we see more cases, it has become an issue,” Dr Guleria said.

“The infection starts off with the lungs. So it is still a pulmonary disease,” Dr Guleria said. “But it has significant vascular problems. It can be termed as a vascular disease to some extent. It can also be termed as a systemic disease because it involves the entire body.”

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Complications persist in recovered patients with severe symptoms, Dr Guleria said. “We have seen a number of patients who have severe pneumonia, where the lungs get totally scarred (in recovered patients); although they come out, some of them require oxygen at home after recovery. Three months down (the line), the CT scans have shown that the lungs are in bad shape… Some patients over weeks have complained of weakness, and do not have the energy to go back to work. In some cases, there are serious neurological problems (after recovery)” he said.

While researchers across the world are studying whether antibodies developed by the body in response to the virus provide permanent immunity, Dr Guleria said that data are emerging in India that cell-mediated immunity, an immune response that does not involve antibodies, may also be protecting the body.

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“…Data is emerging, we are also learning about the body’s immune response; we have realised that cell-mediated immunity is also activated and giving protection through the T-cells in the blood. We may be protected to some extent, more than what we are thinking right now. The big question is how long does the protection last. That is difficult to predict,” he said.