Korean J Geriatr Gerontol.  2022 Dec;23(2):115-122. 10.15656/kjcg.2022.23.2.115.

A Study on The Efficacy of Vaccination in Elderly Patients with Breakthrough COVID-19 Infection

• Choi S
• Choi Z
• Ha CM
• Lee HJ
• Kim Cm

• KMID: 2566380
• DOI: http://doi.org/10.15656/kjcg.2022.23.2.115

Abstract

Background
Old age is one of the risk factors for COVID-19, and previous studies, mainly in the U.S., have shown that the COVID-19 vaccine has obvious efficacy in reducing the morbidity and progression to severe disease. This study focused on whether vaccination affects the disease progression in elderly COVID-19 patients in South Korea.
Methods
We divided COVID-19 patients over 65 years of age hospitalized at a single medical institution into a vaccinated group and an unvaccinated group, a the progression group and the improvement group, and cross-analyzed them with a chi-square test, and then obtained the odds ratio by binary logistic regression analysis.
Results
Of the total patients, 14 (4.3%) in the vaccinated group (n=323) and 29 (23.4%) in the unvaccinated group (n=124) were in the progression group, showing a significant difference (P=0.000). Subsequent binary logistic regression analysis showed that the odds ratio was 0.112 (P=0.000), indicating that vaccination had a significant effect on reducing the progression to severe disease.
Conclusion
The COVID-19 vaccine is effective in reducing progression to severe disease in older patients with breakthrough infection, and vaccination is recommended for elderly patients.

Keyword

Aged; COVID-19; Disease progression; Vaccination