Effectiveness of BNT162b2 and ChAdOx1 nCoV-19 COVID-19 vaccination at preventing hospitalisations in people aged at least 80 years: a test-negative, case-control study.
Lancet Infect Dis. 2021 Nov;21(11):1539-1548. doi: 10.1016/S1473-3099(21)00330-3. Epub 2021 Jun 23.
Lancet Infect Dis. 2021.
PMID: 34174190
Free PMC article.