Combining a first dose of the AstraZeneca COVID-19 vaccine with a second from Moderna could mean a higher level of protection from COVID-19. That’s according to researchers at National Taiwan University Hospital, which announced the preliminary results of its vaccine mixing study on Friday.
The study found that combining one dose of AstraZeneca with a second dose of Moderna produced a neutralizing antibody level similar to two doses of the Moderna vaccine.
Recent research has suggested that neutralizing antibody levels is a good way of predicting immune protection from symptomatic infection with COVID-19.
The National Taiwan University Hospital study also found that the neutralizing antibody level was higher in participants who were given mixed doses eight weeks apart, rather than four weeks. However, side effects were more common in participants who received two doses of Moderna or a combination of AstraZeneca and Moderna doses. All combinations were less effective against the Delta variant of COVID-19 than against the Alpha variant.
The study divided 399 participants into three groups of 100 and one group of 99. One group received two doses of the AstraZeneca vaccine, and another received two doses of the Moderna vaccine. The remaining two groups received a combination of AstraZeneca and Moderna, one group at an interval of four weeks, and the other at an interval of eight weeks.
On Thursday, Taiwan opened up registration for vaccine mixing using a second dose of Moderna or the Pfizer-BioNTech vaccine. National Taiwan University Hospital researcher Sheng Wang-huei says other studies have shown that vaccine mixing with the Pfizer-BioNTech vaccine is effective.