Neutralizing Antibody-Based Therapies against COVID-19

The novel coronavirus infection (COVID-19) that emerged from Wuhan, China in December 2019 caused a global health crisis. With confirmed cases worldwide exceeding 40 million and continuing to grow, many research groups have been working to develop therapeutics and vaccines against COVID-19. In fact, some vaccine candidates are currently being tested in the clinical phase. The primary target of most of the studies is the spike glycoprotein of the SARS-CoV-2 virus, which binds to ACE2 receptors and allowing the virus entry to the host cells for the initiation of infection. Drugs such as Hydroxychloroquine and Favipiravir only aim to minimize symptoms but cause severe side effects in patients. On the other hand, neutralizing antibodies represents an important strategy for the treatment of COVID-19. Therapeutic neutralizing antibodies against SARS-CoV-2 spike protein can induce antibodies to block virus binding and fusion, thus inhibiting viral infection. Clinical studies show that antibodies obtained from plasma of recovered patients can improve prognosis and increase the survival rate. However, obtaining a high amount of plasmabased antibodies is a major problem in practice, therefore there is an urgent need to develop and produce reliable, high-yield, and specific antibodies against COVID-19. Instead of convalescent plasma therapy, monoclonal antibodies, and other antibodybased therapies such as IgY antibodies, camelid antibodies/nanobodies offer a promising alternative. In this chapter, a perspective on antibody-based approaches currently developed against SARS-CoV-2 by given some fundamental knowledge about these neutralizing antibodies and their potential for the treatment of COVID-19 is presented.

Keywords: Camelid antibodies, Convalescent plasma therapy, IgY antibodies, Monoclonal antibody, Neutralizing antibodies, SARS-CoV-2.