World-wide outbreaks of hand, foot, and mouth disease (HFMD) have been caused by the Coxsackievirus A-16 (CA16). Vaccines and antiviral medicines are not yet available for CA16-associated illness. CA16-specific monoclonal antibody NA11F12 was developed in this work using an epidemic strain of this virus. RD cells revealed that NA11F12 had significant cross-neutralization activity against various CA16 subgenotypes, but not EV71. CA16 A, B1, B2, and C sub genotypes were neutralized by NA11F12 at a 1:1024 to 1:12288 titer, whereas the EV71 strain was neutralized at less than 8. Single NA11F12 therapy provided excellent protection against fatal challenges with CA16 in the newborn mouse model in a dose- and time-dependent manner. Infected newborn mice might be protected from CA16 mobility and death by giving more than 0.1 g/g of NA11F12. Mice were completely protected against CA16-associated illness after a single treatment of 10 g/g NA11F12. When NA11F12 was administered at day 5 post-infection and day 6 post-infection, 80 percent and 60 percent of mice were protected, respectively.

NA11F12 substantially inhibited CA16 VP1 expression in diverse tissues and avoided CA16-induced necrosis, according to immunohistochemical and histological analyses. Finally, a CA16-specific MAb NA11F12 with strong cross-neutralization activity was discovered, which could successfully prevent mice from a fatal CA16 challenge. In the future, it might be a therapeutic MAb against CA16.

Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1565266