Doctors Association Kashmir (DAK) on Sunday said not all patients who have recovered from Covid-19 infection can be plasma donors.“Many recovered patients do not develop enough antibodies in their blood that is needed to fight against the novel coronavirus,” said DAK President and influenza expert Dr Nisar ul Hassan.Quoting a Chinese study, he said more than 30 percent of recovered Covid-19 patients had low levels of antibodies. “6 percent of cases had no detectable levels of antibodies,” he added.Dr Nisar said similar findings were observed by doctors at India’s first convalescent plasma bank at Institute of Liver and Biliary Sciences in Delhi.“3 out of 10 people who had recovered from Covid infection were found to have less than the desired antibody levels,” he said.“An antibody titer of at least 1:160 in the plasma of a donor is considered to be adequate for transfusion,” he added.Dr Nisar said even recovered patients with adequate antibody response lose their antibodies within 8 weeks of time.“We should be looking for antibody levels in the recovered patients before they donate plasma to ensure that they are the right candidates for donation,” he said.“But, Kashmir hospitals transfuse donated plasma to patients without knowing the antibody titer,” he added.Dr Nisar said while some patients showed improvement following plasma therapy, the condition of some other worsened.“Those patients who improved received at least one additional therapy including antiviral, antibiotic or steroid,” he said.Dr Nisar said lack of antibodies in recovered Covid-19 patients has implications.“It puts the recovered patients at the risk of being infected again which would bring us back to square one, where everyone is at risk of infection,” he said.“This will also affect the herd immunity which is one way to stop the virus from spreading in the population,” he added.“Vaccine developers may need to pay particular attention to this. If the real virus could not induce antibody response, the weakened version in the vaccine might not work in these patients either,” said Dr Nisar.(KNT)