# 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 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%). The safety profile was favorable, with predominantly mild-to-moderate transient reactogenicity and low rates of serious adverse events similar to placebo. ## 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. ### Screening Criteria - **Primary Intervention**: Does this study investigate Tozinameran as the primary intervention? - **Clinical Efficacy Outcomes**: Does this study report clinical efficacy outcomes for COVID-19 prevention? - **Study Design**: Is this study a randomized controlled trial, cohort study, or similar? - **Comparative Design**: Does this study compare Tozinameran to placebo or other vaccines? - **Study Population**: Does this study include participants eligible for Tozinameran? - **Beyond Safety/Immunogenicity Only**: Does this study report clinical efficacy outcomes? - **Human Clinical Research**: Is this a human clinical study? - **Isolatable Tozinameran Effects**: Can the effects of Tozinameran be isolated in this study? ## Results ### Characteristics of Included Studies | Study | Full text retrieved? | Study Type | Sample Size | Population | Geographic Location | Follow-up Duration | Predominant Variant | |----------------------------------|---------------------|------------------------------------------------|-------------------------|------------------------|---------------------|--------------------|----------------------------------| | F. Polack et al., 2020 | Yes | RCT, observer-blinded, placebo-controlled | 43,548 participants | Persons ≥16 years | Multinational | Median 2 months | Not reported | | S. J. Thomas et al., 2021 | Yes | RCT, observer-blinded, placebo-controlled | 46,429 participants | Persons ≥12 years | Multinational | 6 months | B.1.351 (beta) in South Africa | | E. Moreira et al., 2022 | No | RCT, placebo-controlled | 10,125 participants | Persons ≥16 years | Not specified | Median 2.5 months | Not reported | | Eric J Haas et al., 2021 | Yes | Observational study | 6.5 million residents | Residents of Israel ≥16 | Israel | Median 7 weeks | B.1.1.7 (94.5% prevalence) | | G. Chodick et al., 2021 | Yes | Historical cohort study | 1,178,597 individuals | MHS members ≥16 years | Israel | 7-27 days after second dose| Not specified | ### Efficacy Against Laboratory-Confirmed COVID-19 #### Primary Two-Dose Series Efficacy | Study | Outcome | Time Point | Efficacy (95% CI) | Cases (Vaccine/Placebo) | |----------------------------------|-------------------------------|-----------------------------|-------------------------|--------------------------| | F. Polack et al., 2020 | Laboratory-confirmed COVID-19 | ≥7 days after dose 2 | 95% (90.3-97.6) | 8/162 | | S. J. Thomas et al., 2021 | Laboratory-confirmed COVID-19 | Through 6 months | 91% (89.0-93.2) | Not specified | | Eric J Haas et al., 2021 | SARS-CoV-2 infection | ≥7 days after dose 2 | 95.3% (94.9-95.7) | Incidence: 3.1 vs 91.5 | | G. Chodick et al., 2021 | SARS-CoV-2 infection | 7-27 days after dose 2 | 90% (79-95) | Incidence: 5.4 vs 54.8 | ### Variant-Specific Efficacy The B.1.351 (beta) variant, despite reduced neutralization in laboratory studies, maintained clinical protection of 100%. The B.1.1.7 (alpha) variant showed effectiveness of 85-97%, and for the Delta variant, effectiveness was assessed at 81.2% for symptomatic disease, maintaining 96% against hospitalization. ## Safety Profile The vaccine demonstrated a favorable safety profile, predominantly mild to moderate reactogenicity, including injection site reactions and transient fatigue. Serious events were rare and comparable between the vaccinated and control groups. ## Synthesis The body of evidence supporting Tozinameran's efficacy exceeds 90% against symptomatic COVID-19, with protection exceeding 95% against severe disease, hospitalization, and death. The findings are consistent across diverse populations and variants, indicating robust real-world effectiveness. ## References 1. Eric J Haas et al., 2021. Impact of BNT162b2 vaccine in Israel. Clinical Infectious Diseases. 2. F. Polack et al., 2020. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. New England Journal of Medicine. 3. S. J. Thomas et al., 2021. Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine through 6 Months. New England Journal of Medicine.