J&J COVID-19 shot gets better boost from Moderna or Pfizer in NIH study

People who got Johnson & Johnson Inc’s COVID-19 vaccine as a first shot had a stronger immune response when boosted with vaccines from Pfizer Inc/BioNTech SE or Moderna Inc, a study run by the National Institutes of Health showed on Wednesday. The study, which is preliminary and hasn't been peer reviewed, is the latest challenge to J&J's efforts to use its COVID-19 vaccine as a booster in the United States. The study, which included more than 450 adults who received initial shots from Pfizer, Moderna, or Johnson & Johnson, showed that 'mixing and matching' booster shots of different types is safe in adults. Moderna's and Pfizer's vaccines are based on messenger RNA while J&J's uses viral vector technology.