Combining COVID vaccines produces as many or more antibodies as using the same vaccine as a booster, according to preliminary results from a highly anticipated government-sponsored trial of USA.
The trial is the first major study in the United States to compare the effects of using different vaccines as a booster or initial vaccines. The complex nine-arm trial involved more than 450 people and measured the effects of giving a booster vaccine from Moderna, Pfizer-BioNTech SE, or Johnson and Johnson to those who had originally received a different vaccine.
In general, the results showed that the combination resulted in comparable or higher levels of neutralizing antibodies compared to boosting with the same vaccine, the researchers said in the preliminary version of the study published on medRxiv.org. The adversity rates were similar in all the different booster groups, the study found.
“These data suggest that if a booster vaccine is approved or licensed, it will generate an immune response independent of the primary vaccination regimen against COVID-19,” the researchers concluded.
The results of the ongoing trial have not yet been peer-reviewed or published in a medical journal. More details about the study are expected to be revealed Friday afternoon at an FDA advisory panel meeting, where researchers conducting the trial will make a presentation on their initial findings.
Mixing and matching reinforcements has become an increasingly important topic. Many countries outside the United States have used the method in an attempt to maximize the effectiveness of the vaccine or avoid unusual side effects associated with some vaccines.
In the United States, some people who received the Johnson & Johnson vaccine may be interested in receiving a messenger RNA vaccine as a booster. What’s more, combining could make it easier to implement boosters more broadly, as people receiving boosters could receive any available COVID vaccines at their pharmacy and they would not have to look for the specific vaccine they had previously received.
Outside the United States, concern over cIsolated Cases of Blood Clots Associated With AstraZeneca Vaccine led many countries in Europe to discontinue use of the vaccine and instead administer a second, different dose. In the UK, health authorities implemented a booster program for an additional dose of Pfizer vaccine as the preferred option, and also offered half a dose of Moderna vaccine as an alternative.