Challenges and Issues of Anti-SARS-CoV-2 Vaccines.

Sophie Blumental,Patrice Debré

doi:10.3389/fmed.2021.664179

Abstract

At the beginning of 2021, anti-SARS-CoV-2 vaccination campaigns had been launched in almost 60 countries with more than 500 million doses having been distributed. In addition to the few vaccines already in use, many other candidates are in preclinical phases or experimental stages in humans. Despite the fact that the availability of anti-SARS-CoV-2 vaccine constitutes a major advance and appear to be the only way to control the pandemic, some investigation remains to be carried out, and this is notably concerning the impact on transmissibility, the duration of the conferred protection in the mid- and long term, the effectiveness against present and future viral mutants, or the ideal schedule that should be applied. In this paper, we review the circumstances that facilitated such a rapid development of anti-SARS-CoV-2 vaccines and summarize the different vaccine platforms under investigation as well as their present results and perspectives in different settings. We also discuss the indications of vaccination under special conditions, such as a history of previous COVID-19 infection or belonging to extreme age categories like children and elderly. Overall, this review highlights the multiple challenges to face if aiming to find a global solution to the pandemic through high vaccination coverage all over the world.

Highlights

For more than 1 year, SARS-CoV-2 has beenspreading all over the world creating a huge burden of disease with millions of cases of infection and thousands of deaths recorded every day [1].Even though significant advances have been made in patient management, notably thanks to better understanding and treatment of pulmonary and thrombo-embolic lesions, there is currently no universally approved viral treatment, making until recently from physical distancing and hygiene measures the only means of slowing down the pandemic but at heavy psychosocial, educational, medical and economical costs
While the third wave is ongoing in Europe and an upsurge of cases is observed due to new variants issued from neighboring countries, there is rising hope to control the pandemic thanks to the arrival of the awaited vaccines [2, 3]
We aim to clarify the scientific background that allowed for such a rapid development of a vaccine, to provide a summary of the different formulations available, to discuss the perspectives of vaccination campaigns, and to highlight how challenging such a vaccination program could be in the setting of a pandemic due to a new pathogen

Summary

Introduction

For more than 1 year, SARS-CoV-2 has beenspreading all over the world creating a huge burden of disease with millions of cases of infection and thousands of deaths recorded every day [1].Even though significant advances have been made in patient management, notably thanks to better understanding and treatment of pulmonary and thrombo-embolic lesions, there is currently no universally approved viral treatment, making until recently from physical distancing and hygiene measures the only means of slowing down the pandemic but at heavy psychosocial, educational, medical and economical costs. The S-protein was selected as the main target against which an immunization by vaccine should be generated in order to obtain a protective immune response capable to hamper attachment and invasion by the virus the way natural antibodies do. Prior knowledge of these elements from related-coronaviruses studies largely contributed to accelerating the identification of SARS-CoV-2 vaccine targets and the determination of their corresponding genomic sequences [4, 7]

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Discussion

Conclusion