Variants of SARS Coronavirus-2 and Their Potential Impact on the Future of the COVID-19 Pandemic

Announcing a new article publication for Zoonoses journal. In this commentary the authors Xin Li, Kelvin Kai-Wang To and Kwok-Yung Yuen from The University of Hong Kong, Hong Kong, China and the Queen Mary Hospital, Hong Kong, China consider variants of SARS Coronavirus-2 and their potential impact on the future of the COVID-19 pandemic.

The emergence of SARS-CoV-2 variants of concern (VOCs), especially the sweeping spread of the delta variant, and differing public health management strategies, have rendered global eradication of SARS-CoV-2 unlikely.

The currently available COVID-19 vaccines, including the inactivated whole virus vaccines, mRNA vaccines, and adenovirus-vectored vaccines, are effective in protecting people from severe disease and death from COVID-19, but they may not confer good mucosal immunity to prevent the establishment of infection and subsequent viral shedding and transmission.

Mucosal vaccines delivered via intranasal route may provide a promising direction, which, if given as a third dose after a two-dose series of intramuscular vaccination, likely promotes mucosal immunity in addition to boosting the systemic cell-mediated immunity and antibody response. However, immunity induced by vaccination, and natural infection as well, is likely to wane followed by re-infection as in the case of human coronaviruses OC43, 229E, NL63, and HKU1.

It is a challenge to prevent and control COVID-19 worldwide with the increasing number of VOCs associated with increased transmissibility and changing antigenicity. Nevertheless, we may seek to end the current pandemic situation through mass vaccination and gradual relaxation of non-pharmaceutical measures, which would limit the incidence of severe COVID-19. Repeated doses of booster vaccine will likely be required, similar to influenza virus, especially for the elderly and the immunocompromised patients who are most vulnerable to infection.

Keywords: SARS-CoV-2, mutation, VOC, vaccination

Zoonoses is fully open access journal for research scientists, physicians, veterinarians, and public health professionals working on diverse disciplinaries of zoonotic diseases.

Zoonoses is now open for submissions; articles can be submitted online at

Please visit to learn more about the journal.

Editorial Board:

Zoonoses is available on ScienceOpen (


Submissions may be made using ScholarOne (

There are no author submission or article processing fees.


Follow Zoonoses on Twitter @ZoonosesJ; Facebook ( ) and LinkedIn (


eISSN 2737-7474

ISSN 2737-7466