WHO has issued interim guidelines for "mixed beatings" of COVID-19 vaccines

Beijing, December 17 (Xinhua) -- The World Health Organization issued interim guidelines for mixed and matching covid-19 vaccines based on existing research data on December 16. It stressed that vaccination is still the preferred choice to use vaccines produced by the same manufacturer; as more research data are available, adjusting the "mixed-and-match" guidelines is not ruled out.

This guideline is based on recommendations recently made by WHO's Strategic Advisory Group of Experts and applies to all COVID-19 vaccines on WHO's emergency use list. Guidelines recommend that if the first dose is given against a viral vector, the subsequent dose of the Messenger ribonucleic acid (mRNA) vaccine can be given, whether it is a second dose or a booster, and vice versa. If the inactivated vaccine is given initially, follow-up vaccinations with viral vector vaccines or mRNA vaccines may be given.

Based on data on the safety, immunity and efficacy of vaccines, the standard practice is to use vaccines from the same manufacturer throughout the process, WHO says. However, given vaccine accessibility, vaccines from different manufacturers can be flexibly used. Only factors such as "careful consideration of vaccine availability" and "potential advantages and risks of a particular product" can "mixed-up" be launched. WHO recognizes the completion of the full vaccination of "mixed beatings".

This is an exterior view of the World Health Organization headquarters in Geneva, Switzerland, taken on May 20. (Photo by Xinhua news agency reporter Chen Junxia)

According to the interim guidelines, the existing research mainly involves the effect of "mixed beating" on human immunity, and the data on safety is limited, and the "mixed beating" data on inactivated vaccines also needs to be further supplemented. As the research progresses, WHO will reassess the advantages and risks of "mixed-and-matched".

As of 7 December, COVID-19 vaccines on WHO's emergency use list include China's Kexing vaccine and Sinopharm vaccine, India's indigenous vaccine Covaxin, the US Johnson & Johnson vaccine, the UK's AstraZeneca vaccine, the US Modena vaccine and the Pfizer vaccine. Among them, the first three are inactivated vaccines, the fourth and fifth are adenovirus vector vaccines, and the latter two belong to mRNA vaccines.

According to Reuters, in response to the soaring number of new crown infections, insufficient vaccine supply, and slow progress in vaccination, some countries and regions have begun to "mix" vaccines. (Wang Xinfang)