Effectiveness of SARS-CoV-2 Vaccines for Short- and Long-Term Immunity: A General Overview for the Pandemic Contrast

Abstract

Background: The recent COVID-19 pandemic produced a significant increase in cases and an emergency state was induced worldwide. The current knowledge about the COVID-19 disease concerning diagnoses, patient tracking, the treatment protocol, and vaccines provides a consistent contribution for the primary prevention of the viral infection and decreasing the severity of the SARS-CoV-2 disease. The aim of the present investigation was to produce a general overview about the current findings for the COVID-19 disease, SARS-CoV-2 interaction mechanisms with the host, therapies and vaccines' immunization findings.

Methods: A literature overview was produced in order to evaluate the state-of-art in SARS-CoV-2 diagnoses, prognoses, therapies, and prevention.

Results: Concerning to the interaction mechanisms with the host, the virus binds to target with its Spike proteins on its surface and uses it as an anchor. The Spike protein targets the ACE2 cell receptor and enters into the cells by using a special enzyme (TMPRSS2). Once the virion is quietly accommodated, it releases its RNA. Proteins and RNA are used in the Golgi apparatus to produce more viruses that are released. Concerning the therapies, different protocols have been developed in observance of the disease severity and comorbidity with a consistent reduction in the mortality rate. Currently, different vaccines are currently in phase IV but a remarkable difference in efficiency has been detected concerning the more recent SARS-CoV-2 variants.

Conclusions: Among the many questions in this pandemic state, the one that recurs most is knowing why some people become more seriously ill than others who instead contract the infection as if it was a trivial flu. More studies are necessary to investigate the efficiency of the treatment protocols and vaccines for the more recent detected SARS-CoV-2 variant.

Keywords: COVID-19; MERS; Pfizer; SARS-CoV-1; SARS-CoV-2; anti-Spike; antibodies; booster; dentistry; vaccines.

Figure 1

Synthesis of the ACE2 receptors interaction mechanisms of the SARS-CoV-2 viral vector.

Figure 2

Schematic diagram of the structure of SARS-CoV-2 and its Spike protein. The protein S is placed inward on the envelope to form a crown structure consisting of two subunits, S1 and S2. The protein hemagglutinin esterase (HE) is only present in A-series betacoronaviruses. Figure designed by Giovanna Dipalma [45].

Figure 3

SARS-CoV-2. Spike. RNA and N Protein, Envelope, Protein M, Hemagglutinin-esterase dimer (HE). Figure designed by Giovanna Dipalma [76].

Figure 4

Activation scheme of Spike protein. Protein S is placed outward on the envelope to form a corona structure. Protein S consists of two S2 subunits fused. Activation of trypsin, furin, TMPRSS, and cathepsin in fused host cells. Characters designed by Giovanna Dipalma.