Introduction

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19, was declared by the WHO as a global pandemic in March 2020.¹ The pandemic has taken a new shape in the form of emerging SARS-CoV-2 variants exhibiting increased transmissibility, increased disease severity, evasive immune properties, impair neutralization by antibodies from vaccinated individuals or convalescence sera, and reinfection resulting in poor clinical outcomes and posing a threat to human health and public safety. ^2,3

Disease burden

Global

Globally, as of 18th July 2022, there have been 559,469,605 confirmed cases of COVID-19, including6,361,157 deaths reported to WHO.⁴

Canada

In Canada, from 3^rd January 2020 to 18^th July 2022, there have been 3,953,490 confirmed cases of COVID-19 with 41,932 deaths reported to WHO.⁴ Table 6 gives the distribution of confirmed COVID-19 cases reported to Public Health Agency of Canada (PHAC) by vaccination status as of 19th June 2022.⁵

Table 6: Distribution of confirmed COVID-19 cases as per vaccination states
as of 19th June 2022.

United States

In the United States, from 3^rd January 2020 to 18^th July 2022, there have been 88,027,926 confirmed cases of COVID-19 with 1,012,816 deaths reported to WHO.⁴

As per the CDC COVID tracker, the rates of COVID-19 cases were highest in unvaccinated individuals across all age groups (12-17, 18-49, 50-64, and 65+), followed by individuals vaccinated with primary series and individuals vaccinated with primary series and 1+booster doses. ^6,7 The rates of hospitalization were highest in unvaccinated individuals (65+) followed by unvaccinated individuals in age groups 50-64, 18-49, and 12-17. ^6,7 The death rate also was highest in unvaccinated and individuals vaccinated with primary series (65+), followed by individuals in age groups 50-64 and 18-49.^6,7

Inference

Despite unprecedented global efforts, there are numerous challenges at various levels in the management ofCOVID-19 and curbing the pandemic. lnspite of the introduction and availability of vaccines in Canada, there exist a substantial chunk of the population which remains unvaccinated and accounts for a high percentage of hospitalizations and deaths as compared to the population which is vaccinated. Also, there exist cases of breakthrough infections in Canada in vaccinated individuals.

References:

1. Salimi-Jeda A, Abbassi S, Mousavizadeh A, et al. SARS-CoV-2: Current trends in emerging variants, pathogenesis, immune responses, potential therapeutic, and vaccine development strategies. Int lmmunopharmacol. 2021;101(Pt A):108232. doi:10.1016/j.intimp.2021.108232.
2. Chad ha J, Khullar L, Mittal N. Facing the wrath of enigmatic mutations: a review on the emergence of severe acute respiratory syndrome coronavirus 2 variants amid coronavirus disease-19 pandemic [published on line ahead of print, 2021 Jul 28]. Environ Microbiol. 2021;10.1111/1462-2920.15687. doi:10.1111/1462-2920. 15687.
3. Ramesh S, Govindarajulu M, Parise RS, et al. Emerging SARS-CoV-2 Variants: A Review of Its Mutations, Its Implications and Vaccine Effica. Vaccines (Basel). 2021; 9(10):1195. Published 2021 Oct 18. doi:10.3390/vaccines9101195.
4. WHO Coronavirus (COVID-19) Dashboard. https://covid19.who.int/. Last accessed 19th July 2022.
5. Approved COVID-19 vaccine. https://www.canada.ca/en/health-canada/services/drugs-health-products/covid19-industry/drugs-vaccines-treatments/vaccines. html. Last accessed 19Ih July 2022.
6. COVID Data Tracker. https://covid.cdc.gov/covid-data-tracker/#rates-by-vaccine-status. Last accessed 19Ih July 2022.
7. COVID Data Tracker. https://covid.cdc.gov/covid-data-tracker/#covidnet-hospitalizations-vaccination. Last accessed 19th July 2022.