Vaccine-induced strain replacement: theory and real-life implications

Abstract

The value of preventive medicine is superior to treatment with vaccinations occupying high priority. Nevertheless, heavy pressure has started to form in regard to strains not included in vaccines contributing to the changing epidemiology of pathogen subtypes leading to ‘vaccine-induced strain replacement’. Among other mechanisms, increasing fitness of nonvaccine strains and metabolic shifts in the subtypes have been described. Classical examples include pneumococcal infections and viral diseases, such as the human papilloma virus. Recently, it has been described in SARS-CoV-2, leading to the emergence of new subtypes, such as Omicron and Delta variants. The phenomenon has also been reported in Mycobacterium tuberculosis, Neisseria meningitidis and rotavirus. This study addresses the concepts, examples and implications of this phenomenon.

Article Highlights

• The phenomenon of ‘vaccine-induced pathogen strain replacement’ is of great importance and associated with changes in epidemiology of various infectious agents.

• Among other pathogens reported to show the discussed phenomenon, S. pneumoniae, human papillomavirus, Haemophilus influenzae are discussed in our paper.

• The recent SARS-CoV-2 virus responsible for the COVID-19 pandemic has been correlated to the vaccine-induced pathogen strain replacement.

Potential mechanisms involved in vaccine-induced pathogen strain replacement

• Several mechanisms have been proposed to explain vaccine-induced pathogen strain replacement.

• Different efficacy of the used vaccines, beside metabolic shifts seen in different pathogenic strains are addressed.

Implications of vaccine-induced pathogen replacement phenomenon

• Increase numbers of nontargeted pathogens is of great epidemiological and clinical value.

• The phenomenon was linked to multidrug-resistant strains of bacteria such as MRSA.

Conclusion

• Changing epidemiology of strains necessitates continuous surveillance.

• From clinical point of view, acquaintance with vaccine-induced pathogen replacement phenomenon is of paramount importance.

• Vaccine design and related epidemiological impact should be addressed based, among other aspects, to the described phenomenon.

Keywords: :

• human papillomavirus
• Mycobacterium tuberculosis
• SARS-CoV-2
• strain fitness
• Streptococcus pneumoniae
• vaccine-induced strain replacement
• vaccines

Financial disclosure

The authors have no financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Competing interests disclosure

The authors have no competing interests or relevant affiliations with any organization or entity with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Writing disclosure

No writing assistance was utilized in the production of this manuscript.