Chinese researchers have developed an mRNA antibody that provided long-term protection against SARS-CoV-2 in animal tests, representing a promising antibody-based therapy for COVID-19 patients. 

The study, published online in the international journal Cell Research, showed that a neutralizing human monoclonal antibody, called mRNA-HB27-LNP, provided effective protection against SARS-CoV-2 infection in mice for up to 63 days after administration. 

Researchers from the Academy of Military Medical Sciences and Suzhou Abogen Biosciences Co., Ltd. made the antibody on a well-established mRNA-technology platform. 

They tested the protective effect of the antibody with different doses and found that all animals that received either 1 mg/kg or 0.2 mg/kg of mRNA-HB27-LNP survived without any clinical symptoms. Treatment with 0.04 mg/kg of the antibody also achieved an 80-percent survival rate, and only minimal or very mild inflammation was observed.

The mRNA-HB27-LNP treatment also offered complete protection against the SARS-CoV-2 Beta variant in animal models in the study. 

In addition, the mRNA technology-based antibody protected 50 percent of mice from SARS-CoV-2 even 63 days after administration, conferring much longer protection than traditional protein antibodies.

These results with mRNA-HB27-LNP support further clinical development for its potential application in preventing COVID-19, according to the study.