HYDERABAD: Age and new variants could be a deadly combo for some people. The death of SV Prasad, 69-year-old former Chief Secretary who had contracted Covid-19 thrice despite taking two doses of vaccine, has sparked a debate in medical circles with experts saying that they cannot rule out similar tragedies in the aged.
“One factor could be because he was above 65 years. On May 10 this year, the WHO released a scientific brief which found that amongst those above 65 years, the level of protection against reinfection as assessed by RT-PCR positivity rate was estimated to be at 50%. In contrast, among younger people, level of protection against reinfection was nearly 89%. This means older individuals are likely to catch reinfection more easily due to the immune response,” said Dr Kiran Madhala, Critical Care HOD at Nizamabad Government Hospital.
Another crucial factor which can only be ascertained with genome sequencing is the role played by the new notorious B.1.617.2, also called Delta variant which is causing havoc across the country. “Every second sample sequenced in AP after April 15 belongs to this Delta variant. Now it is also being seen in southern Telangana as well and can skip the immune response given by vaccines. A study by Public Health England found that vaccine efficacy after first dose on Delta variant is only 33%. Thus it is crucial for all that to ensure breakthrough infections do not occur, both doses are taken and that no relaxation in Covid-19 norms is done,” Dr Kiran added.
While these could be a confluence of factors that lead to such a tragic case, Dr Kiran said that such a case needs to be further studied and taken with a pinch of salt as often reinfections could merely be “an individual testing positive after a prolonged positivity”.
“There is a clinical possibility of reinfection with Covid, and there are a few reports of patients getting reinfected for the third time as well. However, the lack of availability of genomic sequencing of Covid-19 RT-PCR samples makes the accurate diagnosis of reinfection difficult,” explained Dr Viswesvaran Balasubramanian of Yashoda Hospitals. “Though the incidence of triple reinfected Covid-19 cases is a possibility, the prevalence is negligible in routine clinical practice as of now. Access to standardised genomic sequences of viruses might help in the proper identification of such cases,” he added.