• Haghamad Allzain Mohamed Bulla Assistant Professor In The Department Of Biochemistry- Faculty Of Medicine- Shendi University –Sudan



COVID-19, Vaccine, Efficacy, Safety, Pfizer –Biontech, Astrazenca, Moderna, Johnson & Johnson, Coronavac, Sputnik V

Abstract [English]

Coronavirus -2 (SARS-CoV-2), is a new member of the human coronaviruses family. It is a single-strand positive-strand nucleic acid (ssRNA), It also has  spike (S), membrane (M), envelope (E), and nucleocapsid (N) proteins. The (S) protein is responsible for recognising and binding to receptors on the surface of host cells and plays an important role in the first step of viral infection. Coronavirus-2 is identified in late 2019 as the causative agent of a new disease (COVID-19) outbreak in China associated with severe medical complications and even death in some cases. In March 2020, the World Health Organization (WHO) announced the novel disease outbreak as a pandemic. Current Coronavirus pandemic is the most challenging health emergency to humanity in this century, with globally reported (184 .324 .026) confirmed cases and ( 3. 992. 680) confirmed deaths ,as of 7th  July 2021, according to WHO.

Preventive measures of social distancing face masks wearing, hand washing and lockdown have slowed the spread of COVID-19, but the ideal one is vaccination to protect individuals and create everlasting change and return to normalcy. Efficacy and safety of vaccines is very essential to gain  public trust.

There is a great variation in people’s confidence in vaccines that relies on several factors, including awareness about vaccines, its side effects, safety and efficacy.

The objective of this review is to provide concise sound knowledge concerning the   main approved vaccines for protection against COVID -19 emerged from various phases of vaccines clinical trials and medical practices, to enhance public trust and to tackle vaccine skepticism .

 This study also intended to educate about the vaccine’s side effects, that may prompt individuals to receive the vaccine after comparing the acceptable side effects with the disease’s severity and there by promote communities confidence in the safety of COVID-19 vaccines.

This review examines efficacy and safety profile of some authorized vaccines such as Pfizer/BioNTech mRNA, (BNT162b2), Moderna (mRNA-1273) ,Johnson & Johnson (Janssen), Oxford-AstraZeneca ChAdOx1-S, CoronaVac vaccine and Gam-COVID-Vac  (Sputnik V).

The review concluded that currently authorized COVID-19 vaccines are effective and prevent serious COVID-19 symptoms and related hospitalization and death.  They are safe with acceptable minor local and systemic side effects, reported  by some recipients’ of the vaccine and are similar to the known side effects encountered with previously known vaccines such as seasonal influenza vaccine, as expected outcomes of immune response to the vaccines. The  reported serious side effects were very rare.


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