Humoral response in 59 jamatis recovered from covid 19 during initial phase of covid-19 pandemic in india

Introduction: The SARS-COV-2 that causes COVID 19 disease has been quickly spreading across the world. In recent past, Covid-19 antibody testing has been the focus of much research. The exact nature and the optimal duration of antibodies after certain duration of disease/recovery in COVID 19 is not clearly known. Here in this study we assessed the presence of IgG and IgM antibodies (humoral response) in 59 Jamatis after 5-6 weeks of symptom onset/date of sampling for asymptomatic individuals who were diagnosed as COVID 19 by RT-PCR and admitted in SHKM GMC for treatment and isolation during initial phase of COVID pandemic in 2020.
Material and methods: The jamatis in our district were diagnosed of COVID-19 by RT-PCR done with oropharyngeal and nasopharyngeal swab samples. Signs and symptoms were also noted. 59 individuals that were found COVID 19 positive were admitted in SHKM Government Medical College for treatment and isolation and were tested for Antibodies by SD Biosensor combined IgG/IgM Rapid Antibody detection kit after 5-6 weeks of symptom onset/date of sampling for asymptomatic individuals.
Result: The IgG positivity after 5-6 weeks of symptom onset/date of sampling for asymptomatic individuals was 50.8% while 5.08% showed IgM positive suggestive of active disease. Antibody positivity of sample had no relation with the symptoms. The positivity rate of antibodies in asymptomatic and symptomatic COVID-19 cases was comparable.
Conclusion: The presence of antibodies in only 50.8% of individuals is suggestive of waning of antibodies with the time duration. The relative difference in the colour intensity during antibody test interpretation in different individuals might depend on their immunity status and is a matter of further research. Plasma from IgG positive and convalescent patients can be utilised for plasma therapy. The time duration till which these antibodies will last is not determined by this study.