Vaccines in the Fight Against COVID-19: Mechanisms, Efficacy, and Global Challenges

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This is an unedited manuscript accepted for publication and provided as an Article in Press for early access at the author’s request. The article will undergo copyediting, typesetting, and galley proof review before final publication. Please be aware that errors may be identified during production that could affect the content. All legal disclaimers of the journal apply.

Year : 2025 | Volume : 02 | 02 | Page :
    By

    Dr. V. Basil Hans,

  1. Research professor, Department of Management and Commerce, Srinivas University in Mangalore, Karnataka, India

Abstract

The SARS-CoV-2 pandemic has created an unparalleled public health problem, necessitating comprehensive prevention. This page discusses COVID-19’s evolution, scientific understanding, and quick vaccine production and implementation. It compares the mechanisms, efficacy, and safety profiles of the four major types of COVID-19 vaccines—namely mRNA, viral vector, protein subunit, and inactivated virus vaccines. Each type is evaluated in terms of how it stimulates the immune response, its effectiveness in preventing infection or severe disease, and its known side effects or safety concerns. In addition, the essay delves into the growing issue of vaccine hesitancy, exploring psychological, social, and cultural factors that influence public attitudes. It also highlights the global inequalities in vaccine distribution and access, with a focus on the challenges faced by low- and middle-income countries. Furthermore, it addresses the emergence of novel SARS-CoV-2 variants and the implications for vaccine effectiveness, necessitating the development and administration of booster doses to sustain immunity. The essay concludes by emphasizing that widespread vaccination is critical to controlling the pandemic, and it underlines the need for sustained investment in infectious disease research, public health infrastructure, and international collaboration to prepare for future global health threats.

Keywords: COVID-19, SARS-CoV-2, mRNA vaccines, effectiveness, public health

How to cite this article:
Dr. V. Basil Hans. Vaccines in the Fight Against COVID-19: Mechanisms, Efficacy, and Global Challenges. Recent Trends in Infectious Diseases. 2025; 02(02):-.
How to cite this URL:
Dr. V. Basil Hans. Vaccines in the Fight Against COVID-19: Mechanisms, Efficacy, and Global Challenges. Recent Trends in Infectious Diseases. 2025; 02(02):-. Available from: https://journals.stmjournals.com/rtid/article=2025/view=222532


References

  1. Li YD, Chi WY, Su JH, Ferrall L, Hung CF, Wu TC. From SARS and MERS to COVID-19 vaccine development. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  2. Belete TM. A overview of promising COVID-19 vaccine research. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  3. Onyekere F, Nwankwo V. History, strains, and causes of the coronavirus pandemic. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  4. Rohaim M, El Naggar F, Clayton R, Munir M. Coronavirus non-structural protein structure and function. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  5. Cavanagh D, Britton P. General Coronavirus Features. gov [Internet]. 2008 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  6. Lv J, Gao J, Wu B, Yao M, Yang Y, Chai T, et al. Coronavirus/Animal Influenza Aerosol Transmission. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  7. Ciechanowicz S, et al. Coronavirus disease—cutaneous manifestations 2019—literature review and case reports. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  8. Chung JR, Kim SS, Jackson LA, Belongia EA, King JP, Zimmerman RK, et al. Ambulatory SARS-CoV-2 Patients’ Clinical Symptoms. gov [Internet]. [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  9. Warsi T, Arora S, Rizvi SS, Moosvi AR, Aslam M, Khan MA, Mohammed A. SARS-CoV-2 in Water and Environment—A Scoping Review. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  10. Pascolo S. COVID-19 vaccines: mRNA-based formulations first. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  11. Park H, Park MS, Seok JH, You J, Kim J, Park MS. Analysis of SARS-CoV-2 immunological responses to COVID-19 vaccinations. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  12. Park JW, Lagniton PN, Liu Y, Xu RH. COVID-19 mRNA vaccines—what, why, and how. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  13. Rouf Z, Biswas T, Oishee LM, Muna M. Deciphering mRNA vaccines: a promising cryptic illness platform. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  14. Bezbaruah R, Borah P, Kakoti BB, Al-Shar’I NA, Chandrasekaran B, Jaradat MM, et al. Viral vector-based COVID-19 vaccine candidates’ development. gov [Internet]. [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  15. Lundstrom K. Focus on COVID-19 Vaccine Development using Viral Vectors. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  16. Uskoković V, Alijanianzadeh M, Uversky VN, Ranaei Siadat O, Mozaffari-Jovin S, Sefidbakht Y. An overview of COVID-19 vaccine platforms, focussing on subunit vaccinations. gov [Internet]. 2023 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  17. Okamura S, Ebina H. Live-attenuated vaccinations may control COVID-19. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  18. Vasireddy D, Atluri P, Malayala SV, Vanaparthy R, Mohan G. Review of US Emergency COVID-19 Vaccines. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  19. Belete TM. COVID-19 Candidate Vaccine Update. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  20. Flanagan LK, Best E, Crawford NW, Giles ML, Koirala A, Macartney K, et al. SARS-CoV-2 (COVID-19) Vaccine Progress and Challenges. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  21. Keitel W. Clinical trials of biodefense and emerging/neglected disease vaccines. gov [Internet]. 2009 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  22. Singh JA, Upshur REG. Emergency use designation for COVID-19 candidate vaccines: effects on studies. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  23. Hodgson H, Mansatta K, Mallett G, Harris V, Emary RW, Pollard AJ. What makes a good COVID-19 vaccine? A review of SARS-CoV-2 vaccine clinical efficacy assessment issues. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  24. Gannon J, Azari R, Lomazzi M, Borisch B. Nine Case Studies of COVID-19 Vaccine National Rollout Launch Analysis. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  25. Kuppalli K, Brett-Major D, Smith T. Start 2021 COVID-19 vaccine acceptance now. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  26. Sharma K, Koirala A, Nicolopoulos K, Chiu C, Wood N, Britton NP. Where are COVID-19 vaccines in 2021? gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  27. Flanagan LK, MacIntyre CR, B P, Nelson RM. Current SARS-CoV-2 vaccines. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  28. Bolcato M, Rodriguez D, Feola A, Di Mizio G, Bonsignore A, Ciliberti R, et al. COVID-19 and Equal Vaccine Access. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  29. Van Nguyen S, Thi Nguyen B, Nguyen Viet Duong H, Thanh Lenh P, Trung Tran K, et al. Initial COVID-19 immunisation side effects in Ho Chi Minh City, Vietnam. gov [Internet]. [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  30. Riad S, Alsaad A, Almurikhi A, Alzahrani F, Alghamdi MA, Alzaid EH, Klugar M. Primer dose COVID-19 vaccine side effects: Saudi healthcare workers’ CoVaST-SA experience. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  31. Ramesh S, Govindarajulu M, Parise R, Neel L, Shankar T, Patel S, et al. Emerging SARS-CoV-2 Variants: Mutations, Implications, and Vaccine Efficacy. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  32. Liu S, Kang M, Zhao N, Zhuang Y, Li S, Song T. Comprehensive narrative assessment of real-world COVID-19 vaccines: perspectives and opportunities. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  33. Kim KH. COVID-19 Vaccination for Atherosclerotic Cardiovascular Disease Patients in the Coming Endemic Era. gov [Internet]. 2024 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  34. Spyropoulos TA, Carter C, Jabeen N, Harenberg J, Elalamy I, Falanga A, et al. International Expert Consensus Paper: COVID-19 and the Need for an Integrated and Equitable Approach. gov [Internet]. [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  35. Gudi SK, Tiwari KK. Novel Coronavirus Disease Preparedness and Lessons. gov [Internet]. 2020 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  36. Krammer F. What have we learnt about COVID-19 vaccines? gov [Internet]. 2024 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov
  37. Curran JE, John DS. Must the Weakest Be Vaccinated? Vaccine Distribution Efficiency, Priority, and Equality. gov [Internet]. 2022 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov.
  38. Maeckelberghe E. COVID-19 ethics: global vulnerabilities. gov [Internet]. 2021 [cited 2025 Jul 28]. Available from: https://www.ncbi.nlm.nih.gov.
Ahead of Print Subscription Review Article
Volume 02
02
Received 07/07/2025
Accepted 23/07/2025
Published 28/07/2025
Publication Time 21 Days
65


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