4.1.4 Serum from rabbits immunized with SARS 4.1.4.1 Hypotheses: Serum from rabbits immunized with SARS is more effective than serum from convalescent SARS patients Paraoxonases (PON) are mammalian enzymes associated with anti-oxidant and anti-inflammatory effects [19]. Rabbit PON differs from human PON in terms of more activity and more stability under the circumstances [20]. 4.1.4.2 Rational: Serum from rabbits immunized with the S1 subunit of SARS-S is able to neutralize SARS-CoV2 very efficiently Sera from rabbits immunized with the S1 subunit of SARS-S could effectively reduce the entry of both SARS-S and SARS-2-S [16]. When compared with patient serum, rabbit serum revealed to us higher efficiency in inhibition of SARS-2-S entry at the same concentration.