The Effectiveness Of COVID-19 Vaccination in Protecting Older Adults Against Emerging Infectious and Virulent Strains

Background: With aging, older people are more vulnerable to have a severe COVID-19 infection as their immunity weakens and they are likely having chronic illnesses. As the pandemic develops, more infectious and virulent strains emerge, vaccines are a significant tool to slow the spread of COVID-19, however, there are differences in the response to vaccines among different age groups. Objective: To evaluate the COVID-19 vaccine’s efficacy in protecting the elderly against emerging infectious and virulent strains. Methods: A literature search of PubMed, ScienceDirect, Frontiers and Springer Link databases was performed since the COVID-19 outbreak in December 2019 to the current time. The keywords "SARS-CoV-2", "older adults", "vaccination", "effectiveness", and "COVID-19" to filter out applicable articles and combined visual and numerical summaries to summarize the data. Results: Forty-four articles were found in the literature, and finally ten eligible articles were selected. The selected studies indicated that the elderly can be effectively protected against emerging infectious and highly virulent strains by the COVID-19 vaccination. Conclusion: The COVID-19 vaccination can reduce the incidence of serious disease and mortality in older persons, and booster shots can provide continued protection by increasing the effectiveness of the vaccine, significantly reducing infection rates, rates of serious illness, and mortality in older adults. It is necessary to prioritize the administration of COVID-19 vaccine to the elderly.