Korean J Intern Med.  2022 Mar;37(2):455-459. 10.3904/kjim.2021.409.

Comparison of antibody responses after the 1st and 2nd doses of COVID-19 vaccine with those of patients with mild or severe COVID-19

• Cha HH
• Lim SY
• Kwon JS
• Kim JY
• Bae S
• Jung J
• Kim SH

• KMID: 2527308
• DOI: http://doi.org/10.3904/kjim.2021.409

Abstract

Background/Aims
Data comparing the antibody responses of different coronavirus disease 2019 (COVID-19) vaccine platforms according to dose with natural severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection-induced antibody responses are limited.
Methods
Blood samples from adult patients with mild and severe COVID-19 and healthcare workers who received ChAdOx1 nCoV-19 vaccine (2nd dose at 12-week intervals) and BNT162b2 vaccine (2nd dose at 3-week intervals) were collected and compared by immunoglobulin G immune responses to SARS-CoV-2 specific spike protein using an in-house-developed enzyme-linked immunosorbent assay.
Results
A total of 53 patients, including 12 and 41 with mild and severe COVID-19, respectively, were analyzed. In addition, a total of 73 healthcare workers, including 37 who received ChAdOx1 nCoV-19 and 36 who received BNT162b2, were enrolled. Antibody responses after the first and second doses of the ChAdOx1 nCoV-19 vaccine or the first dose of the BNT162b2 vaccine were similar to those in convalescent patients with mild COVID-19, but lower than those in convalescent patients with severe COVID-19, respectively. However, after the second dose of the BNT162b2 vaccine, the antibody response was comparable to that in convalescent patients with severe COVID-19.
Conclusions
Our data suggest that the second dose of mRNA vaccination may be more beneficial in terms of long-term immunity and prevention of SARS-CoV-2 variant infection than a single dose of COVID-19 vaccination or homologous second challenge ChAdOx1 nCoV-19.

Keyword

SARS-CoV-2; Vaccines; Antibody formation