Federal health officials say the ultra-rare blood clots reported in six people who received the Johnson & Johnson COVID-19 vaccine are similar to the blood clots detected in a very small number of people in Europe who were immunized with the AstraZeneca injection. The United States on Tuesday recommended stopping immunizations with the J&J vaccine until more information is known about how to treat the blood clotting disorder.
J & J’s JNJ, shares of -1.34% fell 1.3% in after-hours trading on Tuesday, and analysts at SVB Leerink said the “pause” was weighing on the shares. Health officials said Tuesday they are reviewing vaccine data to better understand why blood clots occur, and the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices is expected to celebrate an emergency meeting to discuss the J&J vaccine on Wednesday afternoon. All six cases in the US were in women between the ages of 18 and 48. The same SVB Leerink analysts predict that the committee will update its recommendations to say that the vaccine should no longer be given to women under 50 years of age. Women have been disproportionately affected by the disease, both with the J&J vaccine and the AstraZeneca AZN, down -0.47% in Europe. “If someone comes in with this really pretty rare syndrome … the most common way to treat it is with heparin,” said Dr. Anthony Fauci, chief medical adviser to President Joe Biden, during a briefing at the White House. “That would be a mistake in this situation because it could be dangerous and make the situation worse. So there is a clinically relevant reason why you want people to know. “The condition Fauci cited is serious: One person died in the US and another is in serious condition, authorities said, and it is also very rare, occurring in about one in 1 million people who have received the Johnson & Johnson vaccine. The blood clotting disorder is called cerebral venous sinus thrombosis and it was only reported in people who also had low levels of platelets in the blood, a condition called thrombocytopenia. “The real thing that’s so noticeable here is not just cerebral venous sinus thrombosis or thrombocytopenia,” said Dr. Peter Marks, director of the Administration’s Center for Biological Evaluation and Research. Food and Drug Administration, during a separate press conference. “Those two things can happen. It is their occurrence together that creates a pattern, and that pattern is very, very similar to what was seen in Europe.” The AstraZeneca vaccine, which was developed in partnership with the University of Oxford, is licensed in the UK and Europe, where health regulators in some countries have stopped use of the vaccine due to rare reports of blood clots, primarily in women and occurring within the first few weeks after vaccination. This is similar to reports emerging in the US Johnson & Johnson and AstraZeneca COVID-19 vaccines are both adenovirus viral vector-based vaccines. J & J’s injection was licensed in the United States in February and in the European Union in mid-March, although the company said it now plans to delay the launch of its vaccine in Europe. “It’s a similar mechanism to what may be happening with the other adenoviral vector vaccine,” Marks added. “I mean, this is an immune response that happens very, very rarely after some people get the vaccine, and that immune response leads to activation of platelets and these extremely rare blood clots.” No cases of thrombotic syndrome have been reported in people who have received the Pfizer Inc. PFE, + 0.51% or Moderna Inc. MRNA, + 7.40% mRNA vaccines, although there were previous concerns about allergic reactions occurring in people who received those. injections. J&J shares are up 1.3% year-to-date, while AstraZeneca shares traded in the United States are down 1.6%. The broader S&P 500 SPX, + 0.33%, was up 9.9% for the year. Related Stories: • Johnson & Johnson Vaccine Pause: What to Know If You Received or Scheduled the Injection • Johnson & Johnson’s Pause “will not have a significant impact on our vaccination plan,” says the White House • Moderna’s actions and BioNTech surge after regulators halted use of J&J vaccine • US COVID vaccine program faces setback with J&J vaccine as experts say no cause for alarm