Immunogenicity and safety of AZD1222 (ChAdOx1 nCoV-19) against SARS-CoV-2 in Japan: a double-blind, randomized controlled phase 1/2 trial.

Abstract

BACKGROUND:

Immunogenicity and safety of the AZD1222 (ChAdOx1 nCoV-19) vaccine was evaluated in Japanese adults in an ongoing phase 1/2, randomized, double-blind, parallel-group, placebo-controlled, multi-centre trial (NCT04568031).

METHODS:

Adults (n=256, age ≥18 years) seronegative for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) were stratified by age into 18-55- (n=128), 56-69- (n=86) and ≥70-year-old cohorts (n=42), and randomized 3:1 to receive AZD1222 or placebo (two intramuscular injections 4 weeks apart). Immunogenicity and safety were coprimary endpoints. Data collected up to Day 57 are reported.

RESULTS:

Positive seroresponses to SARS-CoV-2 spike and receptor-binding domain antigens were seen in all 174 participants who received two doses of AZD1222. Neutralizing antibody seroresponses were seen in 67.5%, 60.3% and 50.0% of participants receiving AZD1222 aged 18-55, 56-69 and ≥70 years, respectively. Solicited adverse events (AEs) were typically mild/moderate in severity and included pain and tenderness at the injection site, malaise, fatigue, muscle pain and headache. Common unsolicited AEs included pain and tenderness at the injection site, fatigue and elevated body temperature. No vaccine-related serious AEs or deaths were reported.

CONCLUSIONS:

AZD1222 elicited a strong humoral immune response against SARS-CoV-2, and was well tolerated in Japanese participants, including elderly participants.

• Authors: Michiko Asano, Hiroshi Okada, Yohji Itoh, Hajime Hirata, Kensuke Ishikawa, Erika Yoshida, Akiko Matsui, Elizabeth J Kelly, Kathryn Shoemaker, Urban Olsson, Johan Vekemans
• Journal: International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (Int J Infect Dis) Vol. 114 Pg. 165-174 (Jan 2022) ISSN: 1878-3511 [Electronic] Canada
• PMID: 34688944 (Publication Type: Clinical Trial, Phase I, Clinical Trial, Phase II, Journal Article, Multicenter Study, Randomized Controlled Trial)
• Copyright: Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Chemical References

• Antibodies, Neutralizing
• Antibodies, Viral
• COVID-19 Vaccines
• ChAdOx1 nCoV-19

Topics

• Adolescent
• Adult
• Aged
• Antibodies, Neutralizing
• Antibodies, Viral
• COVID-19
• COVID-19 Vaccines
• ChAdOx1 nCoV-19 (adverse effects)
• Double-Blind Method
• Humans
• Japan
• Middle Aged
• SARS-CoV-2
• Young Adult