Elicit: Clinical Efficacy of Tozinameran in COVID-19 Prevention
Clinical Efficacy of Tozinameran in COVID-19 Prevention
What clinical efficacy data support Tozinameran's prevention of COVID-19?
Randomized controlled trials enrolling over 46,000 participants and real-world observational studies including millions of individuals demonstrate that Tozinameran prevents COVID-19 with 91-95% efficacy against symptomatic infection and over 95% efficacy against severe disease, hospitalization, and death across age groups and SARS-CoV-2 variants.
Abstract
Tozinameran demonstrated 95% efficacy (95% CI: 90.3-97.6) against laboratory-confirmed COVID-19 in phase 3 randomized controlled trials, with real-world observational studies confirming 91-95.3% effectiveness. Protection against severe outcomes was exceptionally high, with efficacy of 96.7% against severe disease, 94.3% against hospitalization, and 96.1% against COVID-19-related death. The vaccine also prevented asymptomatic infection with 89-91% efficacy. Efficacy declined gradually from 96.2% in the first two months to 83.7% after four months following the second dose, but a third booster dose administered at a median of 10.8 months restored efficacy to 95.3%. The vaccine maintained substantial protection across SARS-CoV-2 variants, including 100% efficacy against the B.1.351 (beta) variant in South Africa, 85-97% against B.1.1.7 (alpha), and 81-96% against Delta.
Efficacy was preserved across age groups from adolescents (100% efficacy) to adults aged 75 and older (82%), though immunocompromised individuals showed reduced effectiveness of 71%. The safety profile was favorable, with predominantly mild-to-moderate transient reactogenicity, low rates of serious adverse events similar to placebo, and no new safety signals identified with booster doses. These data provide robust evidence that Tozinameran prevents COVID-19 across diverse populations and variants, with particularly strong protection against severe disease, hospitalization, and death.
Methods
We analyzed 10 sources from an initial pool of 200, using 8 screening criteria. Each paper was reviewed for 8 key aspects that mattered most to the research question.
- Records from Elicit search: n = 200
- Papers screened using: Primary Intervention, Clinical Efficacy Outcomes, Study Design, Comparative Design, Study Population, Beyond Safety/Immunogenicity Only, Human Clinical Research, Isolatable Tozinameran Effects.
- Papers included for extraction: n = 10
Screening
We screened in sources based on their abstracts that met these criteria:
- Primary Intervention: Study investigates Tozinameran as the primary intervention.
- Clinical Efficacy Outcomes: Reports clinical efficacy outcomes for COVID-19 prevention.
- Study Design: Randomized controlled trial, cohort study, systematic review, or meta-analysis.
- Comparative Design: Comparison to placebo, other COVID-19 vaccines, or unvaccinated controls.
Characteristics of Included Studies
| Study | Study Type | Sample Size | Population | Geographic Location | Follow-up Duration | Predominant Variant |
|---|---|---|---|---|---|---|
| F. Polack et al., 2020 | RCT, observer-blinded, placebo-controlled | 43,548 participants | Persons ≥16 years | Multinational | Median 2 months | Not reported |
| E. Moreira et al., 2022 | RCT, placebo-controlled | 10,125 participants | Persons ≥16 years | Not specified | Median 2.5 months | Not reported |
| Eric J. Haas et al., 2021 | Observational study | 6.5 million residents | Residents of Israel ≥16 | Israel | Median 7 weeks | B.1.1.7 |
Results
Efficacy against laboratory-confirmed COVID-19 demonstrated high efficacy across both randomized controlled trials and observational studies. The pivotal RCT by Polack et al. showed 95% efficacy, replicated in Israeli observational studies at 95.3% and 90%. Efficacy against symptomatic COVID-19 was particularly high at 94-97%.
Third (Booster) Dose Efficacy
The study by Moreira et al. evaluated a third booster dose administered a median of 10.8 months after the second dose, yielding a relative vaccine efficacy of 95.3% (95% CI: 89.5-98.3).
Efficacy Against Severe Disease Outcomes
Efficacy against severe disease outcomes consistently exceeded 90% across multiple studies, with Israeli national surveillance data demonstrating 97.2% efficacy against COVID-19-related hospitalization.
Safety Profile
The vaccine demonstrated a favorable safety profile across all studies, with predominantly mild-to-moderate reactogenicity and no serious adverse events linked to the vaccine.
Synthesis
The body of evidence for Tozinameran’s clinical efficacy in preventing COVID-19 demonstrates remarkable consistency across diverse study designs, populations, and geographic settings. This review presents strong support for the vaccine’s protection against laboratory-confirmed COVID-19. The gradual decline in efficacy over time was observed, but high-level protection was restored following booster administration.