Immunogenicity Evaluating of the Multivalent COVID-19 Inactivated Vaccine against the SARS-CoV-2 Variants

Young

2022

Ann Acad Med Singap

Introduction: Omicron is the latest SARS-CoV-2 variant of concern, the pathogen that causes COVID-19. Since its emergence in late 2021, Omicron has displaced other circulating variants and caused successive waves of infection worldwide throughout 2022. Omicron is characterised by the rapid emergence of many subvariants and high rates of infection in people with vaccine- and/or infection-induced immunity. This review article will consolidate current knowledge regarding Omicron subvariants, the role of boosters, and future vaccine development. Method: This narrative review is based on a literature search using PubMed. Search terms related to Omicron were used and priority was given to published peer-reviewed articles over pre-prints. Results: Studies indicate that vaccinations and boosters are important to reduce disease severity, hospitalisation and death from Omicron. A variety of factors, such as differing host factors, circulating variants, and forces of infection, can influence the benefit of repeated booster administration. Next-generation bivalent vaccines have now been approved in some countries including Singapore and have demonstrated the ability to induce broad variant protection. Future third-generation vaccines involving mucosal vaccines and/or pan-sarbecovirus vaccines may provide broader and longer-lasting protection. Conclusion: Due to current high levels of vaccine- and infection-induced immunity, it is likely that rates of severe illness, hospitalisation, and death due to Omicron will continue to moderate. Nevertheless, the virus is ever-changing, and public health policies, especially those related to vaccinations, will also have to continually evolve and adapt as COVID-19 transitions to endemicity. Keywords: Booster, COVID-19, infectious diseases, Omicron, vaccine

Section: Bivalent and Multivalent Vaccinesmentioning

confidence: 99%

The Omicron-transformer: Rise of the subvariants in the age of vaccines

Young

2022

Ann Acad Med Singap

Journal of Medical Virology

“…The authors clarified that cellular immune responses could work in their inactivated vaccines, but the mechanism remained to be studied. 116 Moreover, the RBD‐dimer protein subunit vaccine ZF2001 could exhibit a broadly neutralizing antibody response against five VOCs (Alpha, Beta, Gamma, Delta, and Omicron) and three other variants of interest (VOIs) (Epsilon, Eta, and Kappa). 65 , 117 , 118 At present, ZF2001 has been used in China and several other countries.…”

Section: Broad‐spectrum Anti‐coronavirus Vaccinesmentioning

confidence: 99%

Development of variant‐proof severe acute respiratory syndrome coronavirus 2, pan‐sarbecovirus, and pan‐β‐coronavirus vaccines

Zhou

Liu

Zhang

et al. 2022

The newly emerged severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants with high transmission rates and striking immune evasion have posed a serious challenge to the application of current first‐generation SARS‐CoV‐2 vaccines. Other sarbecoviruses, such as SARS‐CoV and SARS‐related coronaviruses (SARSr‐CoVs), have the potential to cause outbreaks in the future. These facts call for the development of variant‐proof SARS‐CoV‐2, pan‐sarbecovirus or pan‐β‐CoV vaccines. Several novel vaccine platforms have been used to develop vaccines with broad‐spectrum neutralizing antibody responses and protective immunity to combat the current SARS‐CoV‐2 and its variants, other sarbecoviruses, as well as other β‐CoVs, in the future. In this review, we discussed the major target antigens and protective efficacy of current SARS‐CoV‐2 vaccines and summarized recent advances in broad‐spectrum vaccines against sarbecoviruses and β‐CoVs.

“…Thus, multiple studies have been conducted to develop multivalent vaccines against SARS-CoV-2. Compared with monovalent vaccines, multivalent SARS-CoV-2 vaccines not only induce better immunogenicity against Omicron but also provides more effective protection against other variants ( 108 – 111 ) ( Table 4 ). Notably, mRNA-1273.214 vaccine which was prepared from ancestral Wuhan-Hu-1 and Omicron B.1.1.529 spike protein mRNAs can induce strong neutralizing antibody responses to Omicron BA.4 and BA.5 subvariants ( 110 ).…”

Section: Introductionmentioning

confidence: 99%

“…Hence, multivalent SARS-CoV-2 vaccines development is considered to play a constructive role in defending against the constantly mutating virus. Notably, a study found that the HB02 + Beta + Delta + Omicron tetravalent vaccine had lower neutralizing antibody titers against most variants than the trivalent vaccine ( 108 ). This seems to suggest that the immunogenicity produced by multivalent vaccines is not only related to the number of polymerized antigens but also to the ratio of antigen during the preparation process.…”

Section: Introductionmentioning

confidence: 99%

The importance of booster vaccination in the context of Omicron wave

Wei

Wang

et al. 2022

Front. Immunol.

Omicron (B.1.1.529) was first detected in a sample collected in Botswana on November 11, 2021, and has rapidly replaced Delta as the dominant global variant given the robust transmissibility. Moreover, it displays a lower virulence than other variants. However, the pathogenicity of Omicron appears to be underestimated in view of the increasing levels of herd immunity through natural infection or vaccination. Additionally, the volume of hospitalizations and deaths increase in proportion to the number of cases due to the high transmissibility of Omicron. Therefore, vaccination remains an important public health priority. Notably, a series of important mutations in the Omicron spike protein, especially in the receptor-binding domain and N-terminal domain, appears to be associated with immune escape capacity, reducing the willingness of people to receive vaccines. Herein, we provide an in-depth discussion to assess the effectiveness of the second and third vaccination against Omicron variant. On the one hand, the two-dose vaccination program adopted by many countries is insufficient to prevent Omicron infection given the mutations correlated with immune escape and the decline in vaccine efficacy over time. On the other hand, booster dose significantly increases the protective efficacy against Omicron infection. Most importantly, heterologous third dose vaccination induces a more robust immune response than homologous booster dose. Therefore, under the special background of this pandemic, there is an urgent need to accelerate the third dose of vaccination, especially providing better booster vaccination strategies, to combat emerging Omicron variant.