IgY ‑ turning the page toward passive immunization in COVID-19 infection (Review)

Abstract

The world is facing one of the major outbreaks of viral infection of the modern history, however, as vaccine development workflow is still tedious and can not control the infection spreading, researchers are turning to passive immunization as a good and quick alternative to treat and contain the spreading. Within passive immunization domain, raising specific immunoglobulin (Ig)Y against acute respiratory tract infection has been developing for more than 20 years. Far from being an obsolete chapter we will revise the IgY-technology as a new frontier for research and clinic. A wide range of IgY applications has been effectively confirmed in both human and animal health. The molecular particularities of IgY give them functional advantages recommending them as good candidates in this endeavor. Obtaining specific IgY is sustained by reliable and nature friendly methodology as an alternative for mammalian antibodies. The aria of application is continuously enlarging from bacterial and viral infections to tumor biology. Specific anti-viral IgY were previously tested in several designs, thus its worth pointing out that in the actual COVID-19 pandemic context, respiratory infections need an enlarged arsenal of therapeutic approaches and clearly the roles of IgY should be exploited in depth.

Generation of Chicken IgY against SARS-COV-2 Spike Protein and Epitope Mapping

“…Although the great potential of chicken IgY for COVID-19 treatment has been proposed by several labs [ 29 , 44 , 46 ], so far, no follow-up data or epitopes of SARS-CoV-2 targeted by IgY have been published. A previous study on chicken IgY produced against SARS-CoV implied that a dominant epitope existed in the “Se-e” fragment located between amino acid residues 456–650 of SARS-CoV S [ 47 ].…”

“…Apart from human antibodies, chicken immunoglobulin Y (IgY) from egg yolk has proved able to neutralize pathogens in the respiratory tract of mice [ 25 – 27 ]. Because of its high specificity and avidity, low risk of adverse immune responses, low manufacture cost, and ease of storage, chicken IgY raised against SARS-CoV-2 is waiting to be tapped into for potential therapeutic application in treating COVID-19 [ 28 , 29 ].…”

Immunogenicity studies of various experimental vaccines in chickens

“…The results shown here presents that polyclonal antibodies anti-HIV, anti- Salmonella , and anti- S. aureus had in their paratopes the information to create anti-ID antibodies (Ab-2) able to release anti-anti-ID (Ab-3). This was first described by Niels Jerne more than 40 years ago and still nowadays it is hopefully used to produce new vaccines (much experimental) against pathogens [13–17]. The mechanism of the generation of Jerne’s network is as followed: An antigen (immunogen) stimulates the synthesis of Abs (Ab1).…”

“…The question is it discovered here widens new perspectives for immunotherapy of existing and emerging infectious diseases? In particular, the preliminary experiments' results open new horizons for future research in the development of oral vaccination for common and neglected microorganisms [17].…”

The bumpy road to achieve herd immunity in COVID-19

“…Although passive immunization is a good therapeutical option in all its facets [73] mainly for difficult cases, it does not install herd immunity.…”