The US drug regulator has warned of an “increased risk” of an immunological disorder among those administered Johnson & Johnson’s single-dose Covid-19 vaccine, known as Janssen, which has had an episodic roll-out in America marked by major manufacturing glitches and suspended use.
Separately, top US health officials also said they would like to see more data before agreeing to Pfizer’s recent assertion that a booster dose of their vaccine might be needed. They had an hour-long meeting with the company’s experts, who cited an Israeli study in support of their recommendation. Israel began administering a booster – third dose – of the Pfizer vaccine to heart-transplant patients and those with compromised immune systems.
Though experts asserted that the benefits of the Johnson & Johnson vaccine outweigh the risk of the disorder, regulators in India would take note of the US warning as the company prepares to launch its single-dose shot there after a general waiver granted by the government from bridging clinical trials.
The US Food and Drug Agency (FDA) said in a warning that “reports of adverse events following use of the Janssen Covid-19 vaccine under emergency-use authorisation suggest an increased risk of Guillain-Barré syndrome during the 42 days following vaccination”.
Guillain-Barré syndrome (GBS) is a rare neurological disorder in which the body’s immune system turns upon the network of nerves located outside of the brain and spinal cord.
Its effect can range from mild and brief weakness to devastating paralysis, preventing the person from breathing without help. Most people are known to recover completely, but some may experience lasting weakness.
The New York Times reported that people familiar with the FDA’s decision said although chances of developing the disorder are low, they are still three to five times higher than the average population of the United States.
About 100 cases of GBS have been detected among the recipients of the J&J vaccine. Of them, 95 were serious enough to require hospitalisation, the FDA said. There was one death.
While acknowledging the findings, Johnson & Johnson said in a statement, “Rare cases of the neurological disorder, Guillain-Barré syndrome, have been reported following vaccination with the Janssen Covid-19 vaccine. Most occurred within 42 days after vaccination. While the chance of having this occur is very low, Johnson & Johnson has updated its Covid-19 vaccine.”
Bloomberg News has reported that regulators in Europe have also recommended a similar warning that AstraZeneca’s Covid-19 vaccine – which retails in India as Covidshield – could lead to an increased risk of GBS.
The FDA cleared the J&J vaccine in April after a pause triggered by reports of six cases of a rare and severe type of blood clot among those administered the shot.
“During the pause, medical and scientific teams at the FDA and the CDC examined available data to assess the risk of thrombosis involving the cerebral venous sinuses, or CVST (large blood vessels in the brain), and other sites in the body (including but not limited to the large blood vessels of the abdomen and the veins of the legs) along with thrombocytopenia, or low blood platelet counts,” the FDA had said then. “The teams at the FDA and the CDC also conducted extensive outreach to providers and clinicians to ensure they were made aware of the potential for these adverse events and could properly manage and recognize these events due to the unique treatment required for these blood clots and low platelets, also known as thrombosis-thrombocytopenia syndrome (TTS)”.
In May, a plant manufacturing the J&J vaccine mixed up ingredients contaminating 15 million doses that were eventually dumped.
