Mutations may make universal Covid vaccine a tough task

BHOPAL: A universal vaccine against Covid-19 may be a challenging task, with the emergence of various mutations in recombinant Covid-19 proteins, according to a study by AIIMS-Bhopal along with McGill University (Canada). “The research into protein attached to Covid-19 shows the antigenic component of the virus showed mutation,” said AIIMS Bhopal director, Dr Sarman Singh.
The study has been published in the Journal of Laboratory Physicians (JLP), the official journal of The Indian Association of Laboratory Physicians (IALP). “Vaccine modification would likely be needed, region to region. It is a major issue. A single vaccine for Covid-19 might not have equal efficacy globally,” he said.
The study is also an indication for the need to reevaluate the efficacy of rapid antigen tests and sero-survey findings. Rapid tests use reagents based on nucleocapsid protein antibodies or spike protein antibodies. The researchers indicate that spike protein may not be “as accepting to protect antibodies” and result in poor sensitivity of rapid tests.

AIIMS Bhopal director, Dr Sarman Singh said, “One type of rapid antigen test uses reagents based on nucleocapsid protein antibodies or spike-protein antibodies. Hence the sensitivity to these tests would be poor.” Spike protein (S-protein) performs two primary tasks that aid in host infection.
The study was conducted between April and May 2020. “Most mutations in the Covid-19 virus were diagnosed in samples from USA. Most were linked to D614G mutation in SARS-CoV-2 spike protein, which reduces S1 shedding and increases infectivity,” he said.
Therein, comes the role of ACE receptors and receptor-binding protein. The virus attaches to cells, creating a situation where antigenic component is adversely affected, says the study. It indicates that pseudoviruses containing these S-proteins were neutralised, giving cause of concern over the efficacy of convalescent plasma therapy. AIIMS-Bhopal did not participate in the trial.
The study ‘Mutations in SARS-CoV-2, Leading to Antigenic Variations in Spike Protein: A Challenge in Vaccine Development’ is authored by Dr Praveen Kumar Singh, Dr Umay Kulsum, Dr Syed Beenish Rufai, Dr S Rashmi Mudliar and Dr Sarman Singh.