The authors report pronounced vaccine reactions after administration of the first dose of the AstraZeneca vaccine and put a dose adjustment up for discussion (1).
In the pivotal study that led to approval of the AstraZeneca vaccine, significantly less adverse reactions after the first dose of vaccine were noted in patients receiving a lower initial dose (2.2 × 1010 viral particles) in comparison to the standard dose (3.5–6.5 × 1010 viral particles) (2). In the age group of 18–55 years, moderate to strong vaccine reactions were associated with low-dose and standard dose administrations and occurred with frequencies of 32% and 53%, respectively. In addition, in this age group and in participants with intervals of at least eight weeks between doses, efficacy of 90.0% was seen in those who received a low dose as prime and then the standard dose, compared to 65.6% in trial participants who received the standard dose at both occasions (3).
Administration of a lower initial dose of AstraZeneca vaccine showed good efficacy with a lower rate of adverse reactions and has the potential to improve acceptance of the vaccination. Furthermore, because of the reduced vaccine use, more people could be vaccinated.
References
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