A review of leading COVID-19 vaccines, the quest for immune protection, and its key challenges. Part 3: Covid-19 vaccines – Key challenges and translational science
dc.contributor.author | Hartshorne, Johan | |
dc.contributor.author | Villiers, Pierre | |
dc.date.accessioned | 2024-03-18T08:38:38Z | |
dc.date.available | 2024-03-18T08:38:38Z | |
dc.date.issued | 2021-05-06 | |
dc.description.abstract | Rationale • Developing and deploying safe and effective COVID-19 vaccines are faced with many challenges and unanswered questions. • Massive amounts of heterogenic scientific data are being generated that are needed rapidly to advance vaccine development, protect people and restore normality. • The purpose of Part 3 of this four-part series is to review the scientific considerations related to key challenges associated with COVID-19 vaccines and immune protection with the focus of making this data more meaningful and open for clinicians. Key points • The primary immunogen (antigen) required to induce neutralising antibodies (humoral) and T cell (cellular) immune responses is the S-protein fragment of SARS-CoV-2. • Currently, the evidence is firmly pointing towards neutralising antibodies, being more critical for protection. • Long-term protective or durable immune memory is driven by virus-specific T cell and B cell responses (adaptive immunity). • Circulating antibody titres are not predictive of T cell immune memory. • Durable immune memory is a crucial factor to sustain herd immunity. • Adjuvants are added to certain vaccines to provoke a more robust and durable immune response. • Adjuvants that provoke TH1-biased immune responses are preferred. • 90% of adults are seropositive for 'common cold' CoV strains. • There is a cross-reactivity between specific T cell of SARS-CoV-2 and 'common cold' CoV's. • Prior infection with 'common cold' can play a potentially protective role. • Seropositive individuals present with a rapid and higher antibody immune response after a single dose with an mRNA vaccine. • Vaccine-induced immune responses resulting in non-neutralising antibodies, low antibody titres, and abnormal T cell responses (TH2- biased) are potential risks for serious enhanced disease events but unlikely events. • Vaccine strategies aimed at inducing high titres on neutralising antibodies and TH1- biased immune responses reduce the risk of serious adverse events. • Emerging variants of concern are extremely infectious, highly transmissible and threatens the protective efficacy of current vaccines. Public health implications • A rapid global vaccination campaign combined with standard mitigation measures to stop transmission is the best defence against the emergence of further SARS-CoV-2 variants and the safest way to attain herd immunity. • Booster immunisations may be required to promote or improve the durability and strength of vaccine immunity. | |
dc.identifier.doi | https://doi.org/10.31730/osf.io/e7udq | |
dc.identifier.uri | https://africarxiv.ubuntunet.net/handle/1/786 | |
dc.identifier.uri | https://doi.org/10.60763/africarxiv/741 | |
dc.identifier.uri | https://doi.org/10.60763/africarxiv/741 | |
dc.identifier.uri | https://doi.org/10.60763/africarxiv/741 | |
dc.subject | adjuvants | |
dc.subject | coronavirus | |
dc.subject | COVID-19 vaccines | |
dc.subject | herd immunity | |
dc.subject | immune escape | |
dc.subject | immune memory | |
dc.subject | immunogen | |
dc.subject | neutralising antibodies | |
dc.subject | SARS-CoV-2 variants | |
dc.subject | vaccination | |
dc.subject | vaccine-induced disease | |
dc.title | A review of leading COVID-19 vaccines, the quest for immune protection, and its key challenges. Part 3: Covid-19 vaccines – Key challenges and translational science |