Polyclonal F(ab') fragments of equine antibodies raised against the spike protein neutralize SARS-CoV-2 variants with high potency.

We used the recombinant trimeric spike (S) glycoprotein in the prefusion conformation to immunize horses for the production of hyperimmune globulins against SARS-CoV-2. Serum antibody titers measured by ELISA were above 1:10, and the neutralizing antibody titer against authentic virus (WT) was 1:14,604 (average PRNT). Plasma from immunized animals was pepsin digested to remove the Fc portion and purified, yielding an F(ab') preparation with PRNT titers 150-fold higher than the neutralizing titers in human convalescent plasma.

Presence of leptospires on genital tract of mares with reproductive problems.

Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. Equine leptospirosis is commonly manifested by recurrent uveitis, reproductive disorders, as abortions, embryonic absorption, stillbirth and the birth of weak foals. The aim of this study was to verify the presence of Leptospira sp or its DNA in genital tract of mares with reproductive problems.