What do systematic reviews say?

SII‐ChAdOx1 – Serum Institute of India/AstraZeneca + University of Oxford vs ChAdOx1 – University of Oxford

SII‐ChAdOx1 – Serum Institute of India/AstraZeneca + University of… showed no clear difference in local reactogenicity eventsb compared with chAdOx1 – University of Oxford (low certainty).

• Efficacy and safety of COVID‐19 vaccines 2022 · Cochrane Headline outcomes only
  RR 0.76 [0.55, 1.05]
  1 study · 400 participants
  Low