New study can help develop effective COVID-19 vaccine

According to a new study, a detailed analysis of antibody responses in patients affected by coronavirus disease 2019 (COVID-19) could help develop an effective vaccine.

Image Credit: National Institute of Allergy and Infectious Diseases, 2020.

The study was published in PLOS Pathogens—an open-access journal—on September 10^th, 2020, by Chao Wu and Rui Huang from Nanjing University Medical School and collaborators.

The latest outcomes prove that the neutralizing activity of antibodies from patients who recovered from COVID-19 is generally not powerful and decreases sharply within a month of hospital discharge.

The entire world is facing an unparalleled challenge with economies and communities affected by the rising COVID-19 pandemic. At present, no effective drugs or vaccine have been approved to prevent or treat the disease.

A better interpretation of antibody responses against the SARS-CoV-2 virus, which is responsible for causing the COVID-19 infection, will offer underlying information for designing effective therapies and a preventive vaccine.

In the new research work, scientists constantly tracked SARS-CoV-2-specific antibody reactions in 7 severe COVID-19 and 19 non-severe patients for a period of seven weeks from the onset of disease.

A majority of the patients produced antibody responses against the SARS-CoV-2 virus, such as the viral nucleoprotein and three portions of the spike protein—the ectodomain, S1 protein, and receptor-binding domain.

While 80.7% of recovered COVID-19 patients had different levels of antibody neutralization activity against the SARS-CoV-2 virus, only a small number of patients elicited a strong level of neutralization activity.

This finding emphasizes the significance of meticulously choosing blood samples from the recovered COVID-19 patients using antibody neutralization assays before administrating them into other COVID-19 patients.

Three to four weeks following hospital discharge, the neutralizing activity of antibodies from the recovered patients decreased considerably, implying that the recovered COVID-19 patients could be probably re-infected with the SARS-CoV-2 virus.

Additionally, patients with severe COVID-19 exhibited a huge amount of non-neutralizing antibodies, which may contribute to the antibody-dependent improvement of infection. According to the study’s authors, the new study offers significant insights for antibody-based intervention, vaccine design, and serological testing.