Highly Neutralizing COVID-19 Convalescent Plasmas Potently Block SARS-CoV-2 Replication and Pneumonia in Syrian Hamsters
Yuki Takamatsu, Masaki Imai, Kenji Maeda, Noriko Nakajima, Nobuyo Higashi‐Kuwata, Kiyoko Iwatsuki‐Horimoto, Mutsumi Ito, Maki Kiso, Tadashi Maemura, Yuichiro Takeda, Kazumi Omata, Tadaki Suzuki, Yoshihiro Kawaoka, Hiroaki Mitsuya
Abstract
Convalescent plasmas obtained from patients who recovered from a specific infection have been used as agents to treat other patients infected with the very pathogen. To treat using convalescent plasmas, despite that more than 10 randomized controlled clinical trials have been conducted and more than 100 studies are currently ongoing, the effects of convalescent plasma against COVID-19 remained uncertain. On the other hand, certain COVID-19 vaccines have been shown to reduce the clinical COVID-19 onset by 94 to 95%, for which the elicited SARS-CoV-2-neutralizing antibodies are apparently directly responsible. Here, we demonstrate that highly neutralizing effect-confirmed convalescent plasmas significantly reduce the viral titers in the lung of SARS-CoV-2-infected Syrian hamsters and block the development of virally induced lung lesions. The present data provide a proof of concept that the presence of highly neutralizing antibody in COVID-19 convalescent plasmas is directly responsible for the reduction of viral replication and support the use of highly neutralizing antibody-containing plasmas in COVID-19 therapy with convalescent plasmas.