U.K. Expands Clinical Trial for Mixing COVID-19 Vaccines Between Four Manufacturers
April 16, 2021
The University of Oxford has expanded its clinical trial investigating the safety and efficacy of interchanging COVID-19 vaccines (1). While interchanging doses will primarily reduce vaccine shortages and allow for more rapid vaccinations, countries such as Germany have already updated vaccine recommendations for mixing vaccines. Those under 60 years of age who have received the AstraZeneca vaccine are recommended to get Pfizer or Moderna for their second dose. This is in response to several dozen blood clotting cases amongst German citizens under 60 years old (2).
The U.K. clinical trial began in February, interchanging vaccine doses between AstraZeneca and Pfizer. As of this past Wednesday, it will expand to include the Novavax and Moderna vaccines. Participants will include women and men 50 years of age and older, who have already received one dose of the COVID-19 vaccine.
Investigators will observe any adverse reactions and compare efficacy rates between mixing doses versus using one manufacturer to complete the vaccine schedule.