FDA Limits Use Of Johnson & Johnson Vaccine Due To Blood Clot Risk

The Johnson & Johnson vaccine is only approved for US adults who can't get other vaccines.

The FDA said that the vaccine should not be used unless other vaccines are available that are less likely to cause TTS.

TTS is rare, affecting about 1 person in 250,000 who takes Johnson & Johnson's vaccine, but it is much more serious than the mild heart inflammations associated with Pfizer and Moderna's Covid-19 vaccines.

The FDA did not cite Guillain-Barr syndrome in its decision to narrow the vaccine.

Peter Marks, director of the FDA's Center for Biologic, said that the decision to narrow its authorization demonstrates the thoroughness of the FDA's safety systems.

In response to the decision, Johnson & Johnson said it had updated its vaccine fact sheet to increase awareness of blood clot side effects, but pointed out that the available data continues to show that getting Johnson & Johnson's vaccine is safer than getting no vaccine.

Pfizer and Moderna's Covid-19 vaccines work by delivering a piece of messenger RNA that instructs cells to build a harmless piece of coronaviruses. In contrast, the Johnson & Johnson vaccine gives instructions to build the immunity-creating coronaviruses using a cold virus that has been rendered harmless and is incapable of reproducing. Pfizer and Moderna's vaccines have been found to be more effective than Johnson & Johnson's vaccine. The vaccine of Johnson and Johnson was found to be less effective than competing vaccines in preventing hospitalization from Covid-19. The Centers for Disease Control and Prevention recommended in March that people who have undergone a course of Johnson and Johnson's vaccine get a booster from Pfizer or Moderna, which can create a stronger immune response and reduce the risk of TTS.

Contra

The CDC still recommends the vaccine for people who had a severe reaction after a vaccine shot, or for people who would otherwise be unvaccinated due to limited access to other vaccines.

Despite the need in developing countries, Johnson has paused vaccine production.