First Doses of COVID-19 Vaccines Tied to Reduced Hospitalisation Risk in Scotland

Pavankumar Kamat


April 30, 2021


  • The mass roll-out of the first doses of the BNT162b2 mRNA (Pfizer-BioNTech) and ChAdOx1 (Oxford-AstraZeneca) vaccines in Scotland was associated with a reduced risk of COVID19-related hospital admissions at 28-34 days.

Why this matters

  • Such large post-licensure epidemiological studies may help assess the effectiveness of vaccines at a population level in a real-world setting, thereby confirming and/or complementing the findings of pre-licensure clinical trials.

Study details

  • This prospective, nationwide study analysed data from the Early Pandemic Evaluation and Enhanced Surveillance of COVID19-EAVE II-database.

  • Data were available for 5.4 million people registered at 940 general practices across Scotland

  • Primary outcome was vaccine effect assessed as COVID19-related hospital admissions or hospital admissions within 28 days of a positive reverse transcription-polymerase chain reaction test for COVID19.

  • Funding: UK Research and Innovation (Medical Research Council), Research and Innovation Industrial Strategy Challenge Fund, Health Data Research UK and others.

Key results

  • Between 8 December 2020 and 15 February 2021, 30% (1,331,993) of 4,409,588 adults were vaccinated.

  • Vaccine effect for the first dose of the BNT162b2 mRNA vaccine was 91% (95% CI, 85-94%) and for ChAdOx1 was 88% (95% CI, 75-94%) against COVID19 hospitalisation at 28-34 days.

  • At 28-34 days, combined vaccine effect against COVID19 hospitalisation across different age groups was:

  • age, 18-64 years: 92% (95% CI, 82-97%);

  • age, 65-79 years: 93% (95% CI, 73-98%); and

  • age, ≥80 years: 83% (95% CI, 72-89%).

  • For people aged ≥80 years, vaccine effect at 28-34 days was 88% and 81% for the BNT162b2 mRNA and ChAdOx1 vaccines, respectively.


  • Short follow-up period.

  • Residual confounding may be present.


Vasileiou E, Simpson CR, Shi T, Kerr S, Agrawal U, Akbari A, Bedston S, Beggs J, Bradley D, Chuter A, de Lusignan S, Docherty AB, Ford D, Hobbs FR, Joy M, Katikireddi SV, Marple J, McCowan C, McGagh D, McMenamin J, Moore E, Murray JL, Pan J, Ritchie L, Shah SA, Stock S, Torabi F, Tsang RS, Wood R, Woolhouse M, Robertson C, Sheikh A. Interim findings from first-dose mass COVID-19 vaccination roll-out and COVID-19 hospital admissions in Scotland: a national prospective cohort study. Lancet. 2021 Apr 23 [Epub ahead of print]. doi: 10.1016/S0140-6736(21)00677-2. PMID: 33901420. View full text

This clinical summary originally appeared on Univadis, part of the Medscape Professional Network.


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