PUNE: Availability of convalescent blood plasma has almost halved in Pune division due to significantly lower concentration of SARS-CoV-2 neutralizing antibodies in the blood sera of last year’s Covid patients.
Suresh Patil, joint commissioner, Food and Drug Administration (FDA), Pune division, told TOI, “Most blood plasma donors recovered from the infection six to seven months ago. They have very low antibody titers (concentration) in their blood. Higher titers of SARS-CoV-2 neutralizing antibodies are believed to have better clinical outcomes than plasma with lower antibody titers. Patients who recovered from Covid infection recently are also showing lower antibody titers in their sera.”
FDA data showed that all of Pune division, which includes five districts, has just 114 units of convalescent plasma currently as against 205 in December last year.
FDA and blood banks said on an average, out of four to five donors, only one might have requisite levels of antibodies currently. Dr Smita Joshi, HOD, Blood Banks, Sahyadri Hospitals, said, “Many of the Covid patients of last year were positive for the infection in April, May and June 2020.The antibodies in the blood of most such patients are currently almost nil. The antibodies last for four months after the infection in most cases. The criteria for plasma donation is 28 days after Covid, maximum up to four months after the infection.”
The spike in cases began from early February this year. The situation is likely to change with more donors expected during the next few days, said Joshi. “We have seen some increase in antibodies’ levels in the last three to four days in some donors so situation may improve,” she said.
Sarika Patil, owner, Aadhar Blood Bank, said not only has it been difficult to find donors, but those who are coming have very low antibody titers. “We have phones ringing after every five minutes for convalescent plasma. Last year around September-October, we had many requests for blood plasma, but it was relatively easier to find donors then as compared now,” she said.
Dr Kapil Zirpe, member of the Pune Covid-19 task force and head of the neurotrauma unit of Ruby Hall Clinic, said, “Trials conducted so far have not been able to prove the effectiveness of plasma therapy in severe cases. I personally do not prescribe plasma therapy for critical patients as it has been found to be ineffective & risky.”