Summary and Future perspectives:
The novel corona virus, SARS-CoV-2, is one of the most challenging
crises that faced the whole world since the 1918 Influenza outbreak
unveiling the hidden weaknesses of the health care systems globally and
urging the need for efficient and safe vaccines and therapies
development. Luckily, vaccine research has advanced dramatically over
the last period, with the creation of multiple types of RNA and DNA
vaccines, approved viral vector vaccines, recombinant peptides in
addition to cell culture based immunotherapies(110) . Based on the high
similarity between SARS-CoV-2 and SARS, the identification of S protein,
present in both viruses and responsible for virus binding to the host
cell membrane and its internalization into the cell has been facilitated
and proposed as the main target for many vaccines under trials. This
will help in quick production of neutralizing antibodies that bind to
the S protein and hence prevent the infection process. Nevertheless,
although many S protein targeting vaccines have been developed already
aiming to protect against SARS and MERS, most of them did not give the
desirable results when tested in animal models or caused severe harmful
effects as lung injury or multiorgan failure(111),(112). In addition,
it is not well-known whether the infection with this virus involves
lifelong immunity nor the possibility of re-infections which urge
researchers all over the world to continue their research on this topic
in order to explore the exact pathophysiology of the virus and to
develop a highly effective vaccine and treatment.
However, the specific immune signaling pathways stimulated by SARS-CoV-2
are still to be well identified as this may ensure a great hope in
revealing the reliable and significant biological markers to be targeted
in vaccines and immunotherapies in order to block the cytokine storm
occurring in most of the severe cases. Moreover, since it is known that
the innate immunity stimulates many signaling pathways, it would be more
promising to target various signaling pathways simultaneously during the
course of treatment which should include a combination of specific
cytokine blockers, corticosteroids as well as S1PR1 agonists instead of
administering only one drug as this may enhance the chance of recovery
especially in advanced cases. Therefore, more studies are needed to
evaluate if this combination of drugs could protect the patients against
the progression of lung damage and multi organ failure compared with
single target drug regime plans.
Finally, all the above-mentioned issues illustrate some of the main
holes in our understanding of COVID-19 physiological implications,
fundamental immune signaling mechanisms, and effective vaccines
development strategies that prospective studies desperately need to
tackle.