The purpose of this Phase 2 study is to assess the safety and immunogenicity of MVC-COV1901 vaccine compared to placebo in participants who are generally healthy or with stable pre-existing health conditions.

This Phase II, prospective, placebo-controlled, double-blinded (investigator/site staff and participants), multi-center, multi-regional study; the Sponsor will be blinded until the interim analysis. Participants who are generally healthy or with stable pre-existing health conditions will be randomized, stratified by age (≥ 20 to < 65 years and ≥ 65 years of age).All eligible participants will be randomized to receive 2 doses of either MVC-COV1901 or placebo in a predefined ratio.

Results

The Lancet reported interim results on October 13, 2021. 

Of 4173 individuals screened between Dec 30, 2020, and April 2, 2021, 3854 were enrolled and randomly assigned: 3304 to the MVC-COV1901 group and 550 to the placebo group. A total of 3844 participants (3295 in the MVC-COV1901 group and 549 in the placebo group) were included in the safety analysis set, and 1053 participants (903 and 150) had received both doses and were included in the per-protocol immunogenicity analysis set. From the start of this phase 2 trial to the time of interim analysis, no vaccine-related serious adverse events were recorded. The most common solicited adverse events in all study participants were pain at the injection site (2346 [71·2%] of 3295 in the MVC-COV1901 group and 128 [23·3%] of 549 in the placebo group), and malaise or fatigue (1186 [36·0%] and 163 [29·7%]). Fever was rarely reported (23 [0·7%] and two [0·4%]). At 28 days after the second dose of MVC-COV1901, the wild-type SARS-CoV-2 neutralising antibody GMT was 662·3 (95% CI 628·7–697·8; 408·5 IU/mL), the GMT ratio (geometric mean fold increase in titres at day 57 vs baseline) was 163·2 (155·0–171·9), and the seroconversion rate was 99·8% (95% CI 99·2–100·0).

Conclusion

MVC-COV1901 has a good safety profile and elicits promising immunogenicity responses. These data support MVC-COV1901 to enter phase 3 efficacy trials.