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, derived from randomized controlled trials enrolling over 46,000 participants and real-world studies including up to 6.5 million individuals, 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.

Paper search

We performed a semantic search across over 138 million academic papers from the Elicit search engine, which includes all of Semantic Scholar and OpenAlex.

Screening

We screened in sources based on their abstracts that met several criteria, including primary intervention, clinical efficacy outcomes, study design, and population characteristics.

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	Randomized Controlled Trial, observer-blinded, placebo-controlled	43,548 participants	Persons ≥16 years	Multinational	Median 2 months	Not reported
Stephen J. Thomas et al., 2021	Yes	Randomized Controlled Trial, observer-blinded, placebo-controlled	46,429 participants (44,165 aged ≥16 years, 2,264 aged 12-15 years)	Persons ≥12 years	Multinational	6 months	B.1.351 (beta) in South Africa
Eric J Haas et al., 2021	Yes	Observational study	6.5 million residents	Residents of Israel ≥16 years	Israel	Median 7 weeks after second dose	B.1.1.7 (94.5% prevalence)
...	...	...	...	...	...	...	...

Efficacy Against 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
Stephen J. Thomas et al., 2021	Laboratory-confirmed COVID-19	Through 6 months	91.3% (89.0-93.2)	Not specified
...	...	...	...	...

Temporal Trends in Efficacy

Time Interval	Efficacy (95% CI)	Study
Dose 1 to dose 2	58.4% (40.8-71.2)	Stephen J. Thomas et al., 2021
7 days to <2 months after dose 2	96.2% (93.3-98.1)	Stephen J. Thomas et al., 2021
2 months to <4 months after dose 2	90.1% (86.6-92.9)	Stephen J. Thomas et al., 2021
≥4 months after dose 2	83.7% (74.7-89.9)	Stephen J. Thomas et al., 2021

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. Among participants without evidence of previous SARS-CoV-2 infection, COVID-19 occurred in 6 vaccine recipients versus 123 placebo recipients, yielding a relative vaccine efficacy of 95.3% (95% CI: 89.5-98.3)

Safety Profile

The vaccine demonstrated a favorable safety profile across all studies. Reactogenicity was predominantly mild to moderate, with the most common events being injection-site pain (79-86%), fatigue (60-66%), and headache (55-65%). Serious adverse events were rare and occurred at similar rates in vaccine and placebo groups.

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. ...