Pre-exposure prophylaxis with 300 mg Evusheld elicits limited neutralizing activity against the Omicron variant

Summary: The Omicron variant of SARS-CoV-2, identified in November 2021, has spread rapidly worldwide and shows resistance to most therapeutic monoclonal antibodies and vaccine-elicited antibodies. However, it can be neutralized by antibodies generated by a booster vaccine dose.

Summary: Transplant recipients treated with immunosuppression have a lower response to COVID-19 vaccines, but previous infection with SARS-CoV-2 provides some protection. A study found that neutralizing anti-RBD IgG antibodies were the primary correlate of protection for transplant recipients. Immunosuppressive drugs may affect the generation of virus-specific B and T follicular helper cells. Administration of a third dose of SARS-CoV-2 mRNA vaccine improved the RBD-specific responses in transplant patients who had not previously responded to two doses of the vaccine.

Summary: The Omicron variant of the SARS-CoV-2 virus has become the dominant circulating strain globally, and three doses of mRNA COVID-19 vaccine are recommended for transplant recipients. However, there is limited research on the immunogenicity of mRNA vaccines specifically against the Omicron variant. This study analyzed the neutralization effects of Omicron in transplant recipients who received three doses of mRNA-1273 vaccine, and the results showed poor neutralizing responses against the Omicron variant in these patients.