Vaccines against SARS-CoV-2 Variants

A special issue of Vaccines (ISSN 2076-393X). This special issue belongs to the section "COVID-19 Vaccines and Vaccination".

Deadline for manuscript submissions: closed (1 July 2023) | Viewed by 17390

Special Issue Editor


E-Mail Website
Guest Editor
Department of Epidemiology, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China
Interests: infectious disease epidemiology; evaluation of vaccine efficacy; vaccine development
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Coronavirus Disease 2019 (COVID-19) has been disastrous for humanity. Different types of vaccines against Severe Acute Respiratory Syndrome-associated Coronavirus-2 (SARS-CoV-2) have been developed with unprecedented speed. Studies showed that these vaccines were safe and highly effective against infection, severe clinical symptoms and death. However, during the two-year SARS-CoV-2 epidemic, several variants of concern (VOC) have evolved. The effectiveness of the COVID-19 vaccines declined significantly against VOCs. Additionally, vaccine-induced protection was reported to wane with time. Thus, vaccines that could protect people against SARS-CoV-2 variants and potential newly emerged coronaviruses are urgently needed. As such, the following questions have arisen: are there any potential techniques to be used for developing such kind of vaccines? What is the key to developing a vaccine against variants? What are the difficulties of the technique? How can we assess the effectiveness? What is the prospect of a universal coronavirus vaccine? What is the development status of universal vaccines against other pathogens?

This Special issue will provide a platform for scholars to communicate their professional views and study results to boost universal coronavirus vaccines development.

Dr. Dingmei Zhang
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Vaccines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • vaccine
  • variants
  • VOC
  • COVID-19
  • SARS-CoV-2

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

11 pages, 2389 KiB  
Article
A Recombinant Protein XBB.1.5 RBD/Alum/CpG Vaccine Elicits High Neutralizing Antibody Titers against Omicron Subvariants of SARS-CoV-2
by Syamala Rani Thimmiraju, Rakesh Adhikari, Maria Jose Villar, Jungsoon Lee, Zhuyun Liu, Rakhi Kundu, Yi-Lin Chen, Suman Sharma, Karm Ghei, Brian Keegan, Leroy Versteeg, Portia M. Gillespie, Allan Ciciriello, Nelufa Y. Islam, Cristina Poveda, Nestor Uzcategui, Wen-Hsiang Chen, Jason T. Kimata, Bin Zhan, Ulrich Strych, Maria Elena Bottazzi, Peter J. Hotez and Jeroen Polletadd Show full author list remove Hide full author list
Vaccines 2023, 11(10), 1557; https://doi.org/10.3390/vaccines11101557 - 01 Oct 2023
Cited by 2 | Viewed by 4081
Abstract
(1) Background: We previously reported the development of a recombinant protein SARS-CoV-2 vaccine, consisting of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, adjuvanted with aluminum hydroxide (alum) and CpG oligonucleotides. In mice and non-human primates, our wild-type (WT) RBD vaccine induced [...] Read more.
(1) Background: We previously reported the development of a recombinant protein SARS-CoV-2 vaccine, consisting of the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein, adjuvanted with aluminum hydroxide (alum) and CpG oligonucleotides. In mice and non-human primates, our wild-type (WT) RBD vaccine induced high neutralizing antibody titers against the WT isolate of the virus, and, with partners in India and Indonesia, it was later developed into two closely resembling human vaccines, Corbevax and Indovac. Here, we describe the development and characterization of a next-generation vaccine adapted to the recently emerging XBB variants of SARS-CoV-2. (2) Methods: We conducted preclinical studies in mice using a novel yeast-produced SARS-CoV-2 XBB.1.5 RBD subunit vaccine candidate formulated with alum and CpG. We examined the neutralization profile of sera obtained from mice vaccinated twice intramuscularly at a 21-day interval with the XBB.1.5-based RBD vaccine, against WT, Beta, Delta, BA.4, BQ.1.1, BA.2.75.2, XBB.1.16, XBB.1.5, and EG.5.1 SARS-CoV-2 pseudoviruses. (3) Results: The XBB.1.5 RBD/CpG/alum vaccine elicited a robust antibody response in mice. Furthermore, the serum from vaccinated mice demonstrated potent neutralization against the XBB.1.5 pseudovirus as well as several other Omicron pseudoviruses. However, regardless of the high antibody cross-reactivity with ELISA, the anti-XBB.1.5 RBD antigen serum showed low neutralizing titers against the WT and Delta virus variants. (4) Conclusions: Whereas we observed modest cross-neutralization against Omicron subvariants with the sera from mice vaccinated with the WT RBD/CpG/Alum vaccine or with the BA.4/5-based vaccine, the sera raised against the XBB.1.5 RBD showed robust cross-neutralization. These findings underscore the imminent opportunity for an updated vaccine formulation utilizing the XBB.1.5 RBD antigen. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Graphical abstract

13 pages, 4951 KiB  
Article
Riding the Omicron BA.5 Wave: Improved Humoral Response after Vaccination with Bivalent Omicron BA.4-5-Adapted mRNA SARS-CoV-2 Vaccine in Chronic Hemodialysis Patients
by Eugen Ovcar, Sammy Patyna, Niko Kohmer, Elisabeth Heckel-Kratz, Sandra Ciesek, Holger F. Rabenau, Ingeborg A. Hauser and Kirsten de Groot
Vaccines 2023, 11(9), 1428; https://doi.org/10.3390/vaccines11091428 - 28 Aug 2023
Viewed by 1060
Abstract
Hemodialysis patients faced an excess morbidity and mortality during the COVID-19 pandemic. We evaluated the effect of second-generation mRNA vaccines against Omicron BA.4 and BA.5 variants of SARS-CoV-2 on humoral immunity. The study population comprised 66 adult hemodialysis patients who have encountered four [...] Read more.
Hemodialysis patients faced an excess morbidity and mortality during the COVID-19 pandemic. We evaluated the effect of second-generation mRNA vaccines against Omicron BA.4 and BA.5 variants of SARS-CoV-2 on humoral immunity. The study population comprised 66 adult hemodialysis patients who have encountered four SARS-CoV-2 antigen contacts through vaccination or infection. We assessed their humoral response using an anti-SARS-CoV-2 spike receptor binding domain IgG antibody assay (S-RBD-ab), measuring neutralizing antibodies against ancestral strain of SARS-CoV-2, Delta, and Omicron in a surrogate virus neutralization test (SVNT), and specifically against BA.5 in a plaque reduction neutralization test (PRNT) before and four weeks after vaccination with Comirnaty Original/Omicron BA.4-5. During the following six months, SARS-CoV-2 infections and symptom severity were documented. The bivalent mRNA vaccine led to a 7.6-fold increase in S-RBD-ab levels and an augmented inhibition of the Omicron variant in SVNT by 35% (median). Seroconversion in the Omicron BA.5-specific PRNT was attained by in 78.4% of previously negative patients (29/37). Levels of S-RBD-ab correlated with inhibition in the Omicron-specific SVNT and neutralization titers in the BA.5-PRNT. Eleven SARS-CoV-2 infections occurred in the six-month follow-up, none of which took a life-threatening course. The bivalent mRNA vaccine improved the SARS-CoV-2 virus variant-specific humoral immunity in chronic hemodialysis patients. Measurement of S-RBD-ab can be used in hemodialysis patients to estimate their humoral immunity status against Omicron BA.5. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

11 pages, 948 KiB  
Article
Comparison of the Disease Severity and Outcome of Vaccinated COVID-19 Patients with Unvaccinated Patients in a Specialized COVID-19 Facility: A Retrospective Cohort Study from Karachi, Pakistan
by Muneeba Ahsan Sayeed, Elisha Shalim, Fizza Farooqui, Shaiza Farman, Maheen Khan, Anika Iqbal, Ishfaque Ahmed, Abdul Wahid Rajput, Abdul Razzaque and Saeed Quraishy
Vaccines 2023, 11(7), 1178; https://doi.org/10.3390/vaccines11071178 - 30 Jun 2023
Viewed by 1811
Abstract
We compared the clinical characteristics and outcome of vaccinated hospitalized COVID-19 patients with unvaccinated hospitalized COVID-19 patients. A retrospective cohort study was conducted at the Sindh Infectious Diseases Hospital and Research Center, Karachi, Pakistan. A total of 1407 hospitalized COVID-19 positive patients were [...] Read more.
We compared the clinical characteristics and outcome of vaccinated hospitalized COVID-19 patients with unvaccinated hospitalized COVID-19 patients. A retrospective cohort study was conducted at the Sindh Infectious Diseases Hospital and Research Center, Karachi, Pakistan. A total of 1407 hospitalized COVID-19 positive patients were included from April 2021 to March 2022, of which 812 (57.71%) were males. Of the 1407, 378 (26.87%) patients were vaccinated while 1029 (73.13%) were unvaccinated. Of the vaccinated patients, 160 (42.32%) were partially vaccinated while 218 (57.68%) were fully vaccinated (vaccine breakthrough infection). Fewer unvaccinated COVID-19 patients survived compared to vaccinated patients (62.5% vs. 70%, RR 0.89, 95% CI: 0.82–0.96, p-value = 0.004). Despite there being more vaccinated patients above 60 years of age (60.05% vs. 47.13%), their risk of mortality was lower by 43% (OR = 0.578; CI = 0.4201 to 0.7980, p = 0.0009). On survival analysis, vaccinated patients had better 30-day survival compared to unvaccinated patients (p = 0.028). Moreover, comparing waves 3–5, unvaccinated patients of wave 4, which was driven by the delta variant, had the worst survival (51.8%, p ≤ 0.001) while vaccinated patients of wave 3 (driven by the alpha variant) had the best survival (71.6%). Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

10 pages, 604 KiB  
Article
Protective Effect of Inactivated COVID-19 Vaccines against Omicron BA.2 Infection in Guangzhou: A Test-Negative Case-Control Real-World Study
by Dingmei Zhang, Jiayi Zhong, Husheng Xiong, Yufen Li, Tong Guo, Bo Peng, Chuanjun Fang, Yan Kang, Jinlin Tan and Yu Ma
Vaccines 2023, 11(3), 566; https://doi.org/10.3390/vaccines11030566 - 01 Mar 2023
Cited by 3 | Viewed by 1373
Abstract
This study aims to explore the relationship between the doses of inactivated COVID-19 vaccines received and SARS-CoV-2 Omicron infection in the real-world setting, so as to preliminarily evaluate the protective effect induced by COVID-19 vaccination. We conducted a test-negative case-control study and recruited [...] Read more.
This study aims to explore the relationship between the doses of inactivated COVID-19 vaccines received and SARS-CoV-2 Omicron infection in the real-world setting, so as to preliminarily evaluate the protective effect induced by COVID-19 vaccination. We conducted a test-negative case-control study and recruited the test-positive cases and test-negative controls in the outbreak caused by Omicron BA.2 in April 2022 in Guangzhou, China. All the participants were 3 years and older. The vaccination status between the case group and the control group was compared in the vaccinated and all participants, respectively, to estimate the immune protection of inactivated COVID-19 vaccines. After adjusting for sex and age, compared with a mere single dose, full vaccination of inactivated COVID-19 vaccines (OR = 0.191, 95% CI: 0.050 to 0.727) and booster vaccination (OR = 0.091, 95% CI: 0.011 to 0.727) had a more superior protective effect. Compared with one dose, the second dose was more effective in males (OR = 0.090), as well as two doses (OR = 0.089) and three doses (OR = 0.090) among individuals aged 18–59. Whereas, when compared with the unvaccinated, one dose (OR = 7.715, 95% CI: 1.904 to 31.254) and three doses (OR = 2.055, 95% CI: 1.162 to 3.635) could contribute to the increased risk of Omicron infection after adjusting for sex and age. Meanwhile, by contrast with unvaccinated individuals, the result of increased risk was also manifested in the first dose in males (OR = 12.400) and one dose (OR = 21.500), two doses (OR = 1.890), and a booster dose (OR = 1.945) in people aged 18–59. In conclusion, the protective effect of full and booster vaccination with inactivated COVID-19 vaccines exceeded the incomplete vaccination, of which three doses were more effective. Nevertheless, vaccination may increase the risk of Omicron infection compared with unvaccinated people. This may result from the transmission traits of BA.2, the particularity and stronger protection awareness of the unvaccinated population, as well as the ADE effect induced by the decrease of antibody titers after a long time of vaccination. It is crucial to explore this issue in depth for the formulation of future COVID-19 vaccination strategies. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

11 pages, 1059 KiB  
Article
Neutralization Effect of Sera against Delta and Omicron in Patients Recovering from COVID-19 and Inactivated Vaccine Recipients
by Yajuan Zhu, Qianhong Zhong, Zhanzhong Ma, Shuang Liu, Yunhua Lan, Bo Peng, Xiaomin Zhang, Xiaolu Shi, Jing Qu, Zhilong Wu, Zhimeng Zhao, Xilin Zhang and Dingmei Zhang
Vaccines 2023, 11(2), 471; https://doi.org/10.3390/vaccines11020471 - 17 Feb 2023
Cited by 1 | Viewed by 1211
Abstract
This study aims to analyze the serum neutralization capacity against Delta and Omicron variants in three clusters of individuals, including those who had recovered from COVID-19 and those who had received two and three doses of inactivated vaccine. Pseudovirus neutralization tests were performed [...] Read more.
This study aims to analyze the serum neutralization capacity against Delta and Omicron variants in three clusters of individuals, including those who had recovered from COVID-19 and those who had received two and three doses of inactivated vaccine. Pseudovirus neutralization tests were performed on serum samples. The neutralizing titers between different groups were compared using the Wilcoxon’s signed-rank test. Among the two-dose vaccinees, the neutralization titers of the Omicron variant were reduced by approximately 3.1-fold compared to the wild-type virus (p < 0.05). Meanwhile, among the three-dose vaccinees, the neutralization titers for Delta and Omicron variants were 3.5-fold (p < 0.05) and 5.0-fold (p < 0.05) lower, respectively, as compared to the wild-type virus. In addition, among the recovering patients, the neutralization titers for Delta and Omicron variants were 3.9-fold (p < 0.05) and 29.1-fold (p < 0.05) lower, respectively, as compared to the wild-type virus. Overall, only 12.0% (11/92) of participants showed neutralizing titers against Omicron above the detection limit. The ability to neutralize wild-type pseudovirus was significantly boosted in three-dose vaccinees as compared to two-dose vaccinees. Sera from recovered patients showed greater neutralizing titers for the wild-type and Delta pseudoviruses than the two- and three-dose inactivated vaccine groups. The present study revealed a loss of neutralizing activity against the Omicron variant in almost all samples. Moreover, the immunization effect obtained through natural infection is more robust than that from the active immunization method of vaccination. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

13 pages, 1394 KiB  
Article
Refocus on Immunogenic Characteristics of Convalescent COVID-19 Challenged by Prototype SARS-CoV-2
by Xiaorong Huang, Chumin Liang, Manman Li, Huimin Chen, Zhaowan Li, Qianqian Ruan, Ximing Hu, Lilian Zeng, Huifang Lin, Wei Zhao, Jianpeng Xiao, Limei Sun and Jiufeng Sun
Vaccines 2023, 11(1), 123; https://doi.org/10.3390/vaccines11010123 - 04 Jan 2023
Cited by 3 | Viewed by 1557
Abstract
Background: Mass basic and booster immunization programs effectively contained the spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, also known as COVID-19. However, the emerging Variants of Concern (VOCs) of COVID-19 evade the immune protection of the vaccine and increase [...] Read more.
Background: Mass basic and booster immunization programs effectively contained the spread of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, also known as COVID-19. However, the emerging Variants of Concern (VOCs) of COVID-19 evade the immune protection of the vaccine and increase the risk of reinfection. Methods: Serum antibodies of 384 COVID-19 cases recovered from SARS-CoV-2 infection were examined. Correlations between clinical symptoms and antibodies against VOCs were analyzed. Result: All 384 cases (aged 43, range 1–90) were from 15 cities of Guangdong, China. The specific IgA, IgG, and IgM antibodies could be detected within 4–6 weeks after infection. A broad cross-reaction between SARS-CoV-2 and Severe Acute Respiratory Syndrome Coronavirus, but not with Middle East Respiratory Syndrome Coronavirus was found. The titers of neutralization antibodies (NAbs) were significantly correlated with IgG (r = 0.667, p < 0.001), but showed poor neutralizing effects against VOCs. Age, fever, and hormone therapy were independent risk factors for NAbs titers reduction against VOCs. Conclusion: Humoral immunity antibodies from the original strain of COVID-19 showed weak neutralization effects against VOCs, and decreased neutralizing ability was associated with initial age, fever, and hormone therapy, which hindered the effects of the COVID-19 vaccine developed from the SARS-CoV-2 prototype virus. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

15 pages, 1262 KiB  
Article
Effectiveness of COVID-19 Vaccines over 13 Months Covering the Period of the Emergence of the Omicron Variant in the Swedish Population
by Yiyi Xu, Huiqi Li, Brian Kirui, Ailiana Santosa, Magnus Gisslén, Susannah Leach, Björn Wettermark, Lowie E. G. W. Vanfleteren and Fredrik Nyberg
Vaccines 2022, 10(12), 2074; https://doi.org/10.3390/vaccines10122074 - 05 Dec 2022
Cited by 5 | Viewed by 5434
Abstract
Background: We estimated real-world vaccine effectiveness (VE) against COVID-19 infection, hospitalization, ICU admission, and death up to 13 months after vaccination. VE before and after the emergence of Omicron was investigated. Methods: We used registered data from the entire Swedish population above age [...] Read more.
Background: We estimated real-world vaccine effectiveness (VE) against COVID-19 infection, hospitalization, ICU admission, and death up to 13 months after vaccination. VE before and after the emergence of Omicron was investigated. Methods: We used registered data from the entire Swedish population above age 12 (n = 9,153,456). Cox regression with time-varying exposure was used to estimate weekly/monthly VE against COVID-19 outcomes from 27 December 2020 to 31 January 2022. The analyses were stratified by age, sex, and vaccine type (BNT162b2, mRNA-1273, and AZD1222). Results: Two vaccine doses offered good long-lasting protection against infection before Omicron (VE were above 85% for all time intervals) but limited protection against Omicron infection (dropped to 43% by week four and no protection by week 14). For severe COVID-19 outcomes, higher VE was observed during the entire follow-up period. Among individuals above age 65, the mRNA vaccines showed better VE against infection than AZD1222 but similar high VE against hospitalization. Conclusions: Our findings provide strong evidence for long-term maintained protection against severe COVID-19 by the basic two-dose schedule, supporting more efforts to encourage unvaccinated persons to get the basic two doses, and encourage vaccinated persons to get a booster to ensure better population-level protection. Full article
(This article belongs to the Special Issue Vaccines against SARS-CoV-2 Variants)
Show Figures

Figure 1

Back to TopTop