Changing epidemiology of COVID-19: potential future impact on vaccines and vaccination strategies

ABSTRACT

Introduction

COVID-19 was an unprecedented challenge worldwide; however, disease epidemiology has evolved, and COVID-19 no longer constitutes a public health emergency of international concern. Nonetheless, COVID-19 remains a global threat and uncertainties remain, including definition of the end of the pandemic and transition to endemicity, and understanding true rates of SARS-CoV-2 infection/transmission.

Areas covered

Six international experts convened (April 2023) to interpret changing COVID-19 epidemiology and public health challenges. We report the panel’s recommendations and knowledge gaps in COVID-19 epidemiology, SARS-CoV-2 evolution, and future vaccination strategies, informed by peer-reviewed publications, surveillance data, health authority assessments, and clinical experience.

Expert opinion

High population SARS-CoV-2 immunity indicates the likely end to the pandemic’s acute phase. Continued emergence of variants/sublineages that can evade the vaccine-induced antibody response are likely, but widespread immunity reduces the risk of disease severity. Continued surveillance is required to capture transition to endemicity, seasonality, and emergence of novel variants/sublineages, to inform future vaccination strategies. COVID-19 vaccination should be integrated into routine vaccination programs throughout life. Co-circulation with other respiratory viruses should be monitored to avoid a combined peak, which could overrun healthcare systems. Effective, combined vaccines and improved education may help overcome vaccine hesitancy/booster fatigue and increase vaccination uptake.

KEYWORDS:

• COVID-19
• epidemiology
• future strategies
• vaccination
• vaccine

Article highlights

• High population SARS-CoV-2 immunity indicates the likely end of the pandemic’s acute phase; continued emergence of transmissible Omicron sublineages and novel variants which are able to evade the vaccine-induced antibody response are likely, but widespread immunity reduces the risk of disease severity.

• In 2023, we reached the end of the acute phase of the COVID-19 pandemic; it is now important to monitor the further development of the virus in the face of a widespread immunity in the human host population.

• Monitoring of the co-circulation of other respiratory viruses, specifically RSV and influenza, should be implemented to avoid a combined peak of viruses, which could overrun healthcare systems.

• COVID-19 vaccination should be integrated into routine vaccination programs throughout life, for a more people-centered approach.

• An effective combined vaccine together with improved vaccine-related education may help overcome vaccine hesitancy or booster fatigue and increase vaccination uptake.

• Vaccine recommendations could be released for different subpopulations, with additional booster vaccinations for adults aged 60 years or older and those with underlying risk factors, such as immunocompromised or pregnant individuals, or those with comorbidities.

Acknowledgments

Medical writing support was provided by Emily Evans, BMedSc, of Ashfield Medcomms, an Inizio company, and funded by Sanofi.

Declaration of interest

M Rolland is funded through a cooperative agreement between The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., and the U.S. Department of the Army, and reports consultancy fees from Sanofi, which were paid to the Henry M. Jackson Foundation for the Advancement of Military Medicine, and travel fees received from Sanofi during the conduct of the study. MC Nunes received grants from BMGF, EDCTP, Sanofi, AstraZeneca, and Pfizer; honoraria from Sanofi; expert testimony fees from Sanofi; participated in an advisory board for Sanofi and a committee for Gavi. C Guerche-Séblain and A Chit are employees of Sanofi and may be stock or shareholders in Sanofi. The authors have no other relevant affiliations or 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 apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contributions

All authors contributed equally to the review, interpretation of the relevant literature, and writing/revision of the article.

Additional information

Funding

Medical writing support for the development of this manuscript was funded by Sanofi. The expert group meeting prior to compiling this paper was convened and funded by Sanofi.