Going to the thitd year since the emerging of Covid-19 virus and its global containment effort that ends up with the ongoing scenario of failure to halt virus spread waves or eradication until now. There are many queries raised in what went wrong with repeayed emerging waves. On the other hand, the newly emerged covid Omicron and the expected future coming variant based on the significance of dry lab sequence analysis outcomes on vaccines protuctivity or virus escape indicated fir the crucial need for web lab that will indicate the how far the current vaccines still offering enough prevention or a new vaccine version is required, this review covers the key preventive action that should be taken towards the ideal Covid eradication strategy.
The Current Covid-19 Vaccines
Principally covid-19 vaccines were approved with great
expectations to protect healthy individuals from exposure to
infection, as well as to enhance recovery and minimize the disease
severities, reduces hospitalization, fatality, terminate infected
healthy carriers and new cases among the vaccinees. Since initiated
covid-19 vaccination in December 2020; and out of more than one
hundred vaccine trials; currently only 14 fast track coronavirus
covid-19 vaccine has been designed, tested & approved. But an
unexpected different scenario took place among the vaccinee as
what currently noticed that some of those fully vaccinated captured
the infection in addition to the raised issues on the vaccines
boosting dosage, number, timing and the best efficient way to
deliver the vaccine in order to induce the best types of protective
immune response/s toward such respiratory pathogens. The
direction and significant of Omicron Covid variant dry-lab analysis
vs wet lab results: Sequences based lab analysis known as dry
lab, while the real phenotypic are wet-lab; the sequences of viral
isolates analyzed in dry lab based showed presence of mutation
in term of many variant including Omicron as a common expected
feature in RNA viruses .
The virus have many structural proteins and genes of which Covid spike is the unique key player that have role on its capacity of invasions to target cell and tissue tropism, bind to receptor/ co-receptor epitope, immunogenicity, passive plasma therapy for sever disease and vaccine success or failure. Covid based sequences outcome should focus on how far its significance the new viral emerged variant such as Omicron in term of the location, number and types of mutation on spike genes S1 & S2, the 3D epitope modified conformation compared to native viral spike and how far the mutations have impact on spike epitopes affinity binding to Ace2 receptor on the fusion of viral particle to target cell and the outcome of the reported mutation on the protective capacity of new variant spike based on wet lab, using the well-known in-vitro virus neutralization test in susceptible VERO-E6 cell lines, towards sera from vaccinee received full Covid vaccines dosage . This wet-lab virus neutralization result outcome remain as the most important and crucial parameter to prove and will tell the reality of legendlegend binding affinity and to give answer for the assumptions raised based on dry-lab sequence analysis about whether those mutations in Omicron spike gene will affect protectivity, partial vaccine escape or fully emerged new viral variant escape totally missmatch the current ongoing Covid vaccines. At any time the wet-lab reported failure of vaccinee sera in virus neutralization, it mean new design of covid vaccine version will urgently require to include the mutant gene or epitopes of both the new Covid variant like Omicron and to maintain the effective and protectiveness of the ongoing covid vaccines.
What Should be Ideal Vaccine Delivery Route toward Covid-19 Eradication
Although covid vaccines offers protection to vaccinees and the
current need for a third boosting dose towards Omicron and the
challenging pressures on manufacturers to meet the increased
covid vaccine market. But still there is a major gap in covid-19
vaccine that clearly appeared on neglecting vaccine delivery route
to consider the crucial issue of vaccine capabilities in blocking the
virus invasion and replication in its target cell & tissue tropism at
entry sites. And the role of spike specific IgA in the neutralization of
covid primary replication, attach of viral spike to ACe2 cell receptor
that terminates presence of healthy carrier vaccinees .
Therefore it is top demand for vaccine capable to induce anticovid- 19 specific mucosal immunity as the key component and most crucial effective mechanisms to halt exposure to infection through blocking early virus entry at the mucosal front line, attached to target cell Aec-2 receptors and inhibits early virus replication among the fully vaccinated population [3-5].
An ideal novel smart covid-19 vaccine need to be designed and delivered to offer the vaccinees with triple immune responses as follows; enough cellular memory and specific higher humoral immunity in term of Covid-19 IgM & IgG responses induced through parenteral immunization routes. In addition to strengthened potent, covid-19 spike-specific mucosal immunity in term of higher covid-19 IgA antibody titer to neutralizes virus inoculum on mucosal lining on upper respiratory, pharyngeal, nasal sites and lung, through mucosal (nasal spray or oral) vaccine delivery as 3rd and 4th doses following initially two parenteral doses [3,6]. Therefore, a new revised covid-19 vaccine design, downstream processing, through encapsulating carrier, mucosal delivery systems post-parenteral dosage to modulate and boost covid-19 spike specific M-cells and APC that promote adherence and transport of vaccine epitopes for triggering covid-19 spike-IgA class-switching as mucosal vaccines that is expected to terminates virus spread and game changer and initialization of pandemic eradication era [7-10]. In addition introduction of such mucosal requires re-adjusting of vaccine testing and efficiency parameters including measurement of covid-19 IgA titer in vaccine and to develop in-vitro neutralization testing protocols & assay for covid-19 mucosal samples (saliva, nasal) and viral specific mucosal dendritic & M-cell flow-cytometry [11,12].
The authors declare that there are no competing interests.
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