Safety and Efficacy of a Third Dose of BNT162b2 Covid-19 Vaccine
New England Journal of Medicine·
- DOI
- 10.1056/nejmoa2200674
- PMID
- 35320659
- PMCID
- PMC9006787
- OpenAlex
- W4220814092
- Study type
- Randomised controlled trial
- Publisher
- Massachusetts Medical Society
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The trial provides randomized evidence that a third BNT162b2 dose given roughly 10–11 months after the primary series had an acceptable short-term safety profile and substantially reduced Covid-19 incidence relative to two doses during a median 2.5-month follow-up, informing booster-dose decision-making.
Structured evidence summary
Research question
Whether a third (booster) dose of the BNT162b2 vaccine, given at least 6 months after the primary two-dose series, is safe and efficacious against Covid-19 in persons 16 years of age or older.
Study design
Ongoing, placebo-controlled, randomized phase 3 trial in which participants who had previously received two 30-μg BNT162b2 doses at least 6 months earlier were assigned to a third BNT162b2 dose or placebo, with safety and efficacy assessed from 7 days after the third dose.
Population and setting
Persons 16 years of age or older who had completed the two-dose BNT162b2 primary series at least 6 months earlier; 5081 received a third dose and 5044 received placebo, with a median interval between dose 2 and dose 3 of about 10.7–10.8 months and a median follow-up of 2.5 months. The setting and countries are not specified in the supplied abstract.
Main findings
Reactogenicity events after the third dose were generally low grade, with no new safety signals and no reported cases of myocarditis or pericarditis. In participants without evidence of prior SARS-CoV-2 infection, Covid-19 onset at least 7 days after dose 3 occurred in 6 vaccine recipients versus 123 placebo recipients, corresponding to a relative vaccine efficacy of 95.3% (95% CI, 89.5 to 98.3) over a median follow-up of 2.5 months.
Public-health relevance
The trial provides randomized evidence that a third BNT162b2 dose given roughly 10–11 months after the primary series had an acceptable short-term safety profile and substantially reduced Covid-19 incidence relative to two doses during a median 2.5-month follow-up, informing booster-dose decision-making.
Important limitations
The summary is limited to the supplied single-article abstract and metadata and therefore requires the original paper for decision-grade interpretation. Limitations explicitly evident from the supplied study design include a short median follow-up of 2.5 months after the third dose, restriction of efficacy analysis to participants without evidence of previous SARS-CoV-2 infection, and an ongoing trial status at the time of reporting.
GIDS interpretation
The article is discoverable under classifiers for COVID-19, vaccination, vaccine effectiveness, and vaccine safety; this reflects topic indexing only and does not constitute linkage to any live surveillance signal.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 11 auditable classifier relationships to diseases, places, topics, and study design.