The European Union’s health bodies have recommended that mixing and matching of approved COVID-19 vaccines can be done for both the initial courses and booster doses, as the region battles rising cases ahead of the holiday season.
Evidence suggests that the combination of viral vector vaccines and mRNA vaccines produces good levels of antibodies against the coronavirus causing COVID-19, the European Medicines Agency (EMA) and the European Centre for Disease Prevention and Control (ECDC) said in a statement
Their endorsement comes after a major study on Monday said a first dose of AstraZeneca or Pfizer-BioNTech shots followed by a Moderna vaccine nine weeks later induced a better immune response.
However, the EMA and ECDC said more research was needed to support the use of mixing and matching in people with weak immune systems, such as older people and those with chronic conditions like cancer, and for two-dose mRNA vaccine regimens.
Longevity of protection offered by vaccines has been under scrutiny and the world is scrambling to trace the Omicron variant as governments are imposing fresh restrictions.
Official rollout of vaccines for 5-11 year olds will start next week in some parts of Europe.
“The use of heterologous schedules may offer flexibility in terms of vaccination options, particularly to reduce the impact on the vaccine rollout should a vaccine not be available for any reason,” the EMA and ECDC said.
The EMA and ECDC recommendations are also meant to help EU member countries with their own vaccination campaigns before any formal EU-wide approval as the health agencies continue studying data on mixing vaccines.
The United States has given the green light to mix-and-match while the World Health Organisation is also assessing the approach.
The EMA and ECDC’s review did not consider vaccines that are not approved in the European Union.
COVID-19 shots from AstraZeneca, Pfizer-BioNTech, Moderna and Johnson & Johnson have been authorised for use in the region.