In a study of patients with COVID being treated in intensive care units, people mounting only a low antibody response against the SARS-CoV-2 virus had a greater risk of dying.
Previous studies by the researchers had indicated that levels of SARS-CoV2 viral RNA and antigens in the blood was related to COVID severity.
The study, which is published in the Journal of Internal Medicine, recruited 92 patients severely ill with COVID who were admitted to the ICU. The researchers found that patients with strong antibody responses against the virus had low levels of viral RNA in their blood, especially anti-S (Spike protein) antibodies. Those with poor antibody responses had high viral RNA levels and disseminated viral proteins in the blood, 2.5 times higher than those with strong antibody responses.
Previous studies have shown that critical COVID patients develop higher titers of SARS-CoV-2 antibodies than those with milder disease, suggesting that antibody response alone is insufficient to avoid severe disease. The findings nonetheless support that critical COVID patients would need to mount a robust anti-S antibody response to survive.
The results could help establish the optimal antibody levels needed for an individual to overcome COVID when critically ill. The study also provided evidence of the importance of antibodies against the Spike protein of SARS-CoV-2 to block the virus’ replication, which are the antibodies induced by vaccination.
“Our findings support that treatment with exogenous antibodies in COVID should be personalised, reserving this therapy for those patients with absent or low endogenous antibodies levels,” said co–senior author Jesús F. Bermejo-Martin, MD, PhD, of the Instituto de Investigación Biomédica de Salamanca (IBSAL) & CIBERES, in Spain.
Source: Wiley
