The National Institutes of Health (NIH) has issued research findings showing that the strength of immunity to the novel coronavirus (COVID-19) is heavily influenced by the amount of antibodies and T cells present in the body. NIH notes that if antibody levels drop, it was helpful to have high T cell levels for immune purposes. To read the NIH announcement and summary of its research findings on the effect of antibody and T cell levels on immunity to COVID-19, use the link below.
https://www.nih.gov/news-events/nih-research-matters/antibodies-t-cells-protect-against-sars-cov-2