An eagerly anticipated study of the “mixing and matching” Covid-19 vaccines found the approach to be safe and effective, although the Moderna and Pfizer-BioNTech vaccines produce a stronger immune system response than Johnson & Johnson.
Mixing and matching refers to the administration of a booster dose of a vaccine different from the type of vaccine used for the first series of vaccinations.
The National Institutes of Health study, published Wednesday and yet to be peer-reviewed, found that people who received the Johnson & Johnson vaccine were stronger after a booster shot from Moderna or Pfizer compared to a booster shot from Johnson Antibody Levels Produced & Johnson. Those originally vaccinated with the Pfizer or Moderna vaccine and given the booster from either company produced similarly strong immune responses, the researchers observed.
The results will be presented to the Advisory Committee of the Food and Drug Administration on Friday. The group will meet on Thursday and Friday to consider recommending a booster shot of the Moderna and Johnson & Johnson vaccines.
The study, which was attributed to 37 doctors and academics, followed 458 volunteers and measured their antibody levels two weeks and four weeks after they were given the boosters. The booster was given four to six months after the original vaccinations.
Individuals were divided into different groups based on their original vaccinations and were given one of three boosters made by Pfizer, Moderna, or Johnson & Johnson. For example, those originally vaccinated with the Pfizer two-dose regimen received either a matching Pfizer booster or a “mixed” booster from either Moderna or Johnson & Johnson.
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