Mixing COVID-19 vaccines leads to more frequent reactions, study shows

The University of Oxford-led Com-COV study – launched to investigate alternating doses of the Oxford-AstraZeneca (LSE: AZN) vaccine and the jab from Pfizer (NYSE: PFE) and BioNTech (Nasdaq: BNTX) – have reported preliminary data.

Findings reveal more frequent mild to moderate reactions in mixed schedules compared to standard schedules.

"Mixed dose schedules could result in an increase in work absences the day after immunization"Writing in a peer-reviewed research letter published in The Lancet, they report that, when given at a four-week interval, both of the ‘mixed’ schedules (Pfizer-BioNTech followed by Oxford-AstraZeneca, and Oxford-AstraZeneca followed by Pfizer-BioNTech), induced more frequent reactions following the second, ‘boost’ dose than the standard, ‘non-mixed’ schedules.