Booster BNT162b2 COVID-19 Vaccination Increases Neutralizing Antibody Titers Against the SARS-CoV-2 Omicron Variant in Both Young and Elderly Adults

• Published in: Journal of Korean Medical Science Vol. 37; no. 9; pp. e70 - 6
• Main Authors: Um, Jihye, Choi, Youn Young, Kim, Gayeon, Kim, Min-Kyung, Lee, Kyung-Shin, Sung, Ho Kyung, Kim, Byung Chul, Lee, Yoo-kyoung, Jang, Hee-Chang, Bang, Ji Hwan, Chung, Ki-hyun, Oh, Myoung-don, Park, Jun-Sun, Jeon, Jaehyun
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Academy of Medical Sciences 2022; The Korean Academy of Medical Sciences; 대한의학회
• Subjects: Adult; Aged; Antibodies, Neutralizing; Antibodies, Viral; BNT162 Vaccine; Brief Communication; COVID-19; COVID-19 - prevention & control; COVID-19 Vaccines; Humans; SARS-CoV-2; Vaccination; 의학일반; COVID-19 Vaccine; Antibodies; Omicron Variant; Immunity; Republic of Korea
• ISSN: 1011-8934; 1598-6357; 1598-6357
• DOI: 10.3346/jkms.2022.37.e70

Concerns about the effectiveness of current vaccines against the rapidly spreading severe acute respiratory syndrome-coronavirus-2 omicron (B.1.1.529) variant are increasing. This study aimed to assess neutralizing antibody activity against the wild-type (BetaCoV/Korea/KCDC03/2020), delta, and omicron variants after full primary and booster vaccinations with BNT162b2. A plaque reduction neutralization test was employed to determine 50% neutralizing dilution (ND ) titers in serum samples. ND titers against the omicron variant (median [interquartile range], 5.3 [< 5.0-12.7]) after full primary vaccination were lower than those against the wild-type (144.8 [44.7-294.0]) and delta (24.3 [14.3-81.1]) variants. Furthermore, 19/30 participants (63.3%) displayed lower ND titers than the detection threshold (< 10.0) against omicron after full primary vaccination. However, the booster vaccine significantly increased ND titers against BetaCoV/Korea/KCDC03/2020, delta, and omicron, although titers against omicron remained lower than those against the other variants ( < 0.001). Our study suggests that booster vaccination with BNT162b2 significantly increases humoral immunity against the omicron variant.