Dataset Information

Persistence of the immune responses and cross-neutralizing activity with Variants of Concern following two doses of adjuvanted SCB-2019 COVID-19 vaccine.

ABSTRACT:

Background

We have previously reported the safety and immunogenicity four weeks after two doses of the Clover COVID-19 vaccine candidate, SCB-2019, a stabilized pre-fusion form of the SARS-CoV-2 S-protein (S-trimer). We now report persistence of antibodies up to 6 months after vaccination, and cross-neutralization titers against three Variants of Concern (VoC).

Methods

In a phase 1 study adult (18-54 years) and elderly (55-75 years) volunteers received two vaccinations 21 days apart with 3, 9 or 30µg doses of SCB-2019 adjuvanted with CpG-1018/alum or placebo. We measured IgG antibodies against SCB-2019, ACE2-competitive-binding antibodies, and neutralizing antibodies against wild type SARS-CoV-2 (Wuhan-Hu-1) at Days 101 and 184, and neutralizing antibodies against three VoC, Alpha (B.1.1.7), Beta (B.1.351) and Gamma (P.1) in Day 36 sera.

Results

Titers waned from their peak at Days 36-50, but SCB-2019 IgG antibodies, ACE2-competitive binding antibodies and neutralizing antibodies against wild type SARS-CoV-2 persisted at 25-35% of their observed peak levels at Day 184. Day 36 sera also demonstrated dose-dependent increases in neutralizing titers against the three VoC.

Conclusions

SCB-2019 dose-dependently induced immune responses against wild-type SARS-CoV-2 which persisted up to Day 184. Neutralizing antibodies were cross-reactive against three of the most prevalent VoC.

SUBMITTER: Richmond PC

PROVIDER: S-EPMC8499965 | biostudies-literature |

REPOSITORIES: biostudies-literature

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