The US Food and Drug Administration (FDA) announced a new warning for the Covid-19 vaccine Johnson & Johnson this week, prompting more concern about the controversial one-shot vaccine.
About 100 cases of the Guillain-Barré syndrome have been reported after at least 12.8 million doses of the Johnson & Johnson vaccine have been administered in the United States, according to a statement by the country’s Centers for Disease Control and Prevention (CDC).
Of the 100 cases, 95 of them were serious and required hospitalization, although no death occurred. The cases are mostly reported two weeks after the vaccination and mostly among men aged 50 and older, according to the CDC, with most people recovering from the syndrome.
Although the preliminary evidence is limited and merely suggests a link between the Johnson & Johnson vaccine and the risk of Guillain-Barré, “it is insufficient to establish a causal relationship,” the FDA said.
The Johnson & Johnson Covid-19 vaccine or the Janssen Covid-19 vaccine is a viral vector vaccine developed by Janssen Vaccines in Leiden, Netherlands and its Belgian parent company Janssen Pharmaceuticals which are subsidiaries of the American company Johnson & Johnson.
The viral vector vaccine is based on a human adenovirus, or a DNA genome that has been modified to contain the gene for making the spike protein of the Covid-19 virus that causes disease. The body’s immune system will respond to the spike protein triggered by the vaccine to produce antibodies to fight the genomes of the virus.
With an efficacy rate of 85 per cent in preventing severe Covid-19 cases and 100 per cent efficacy rate in preventing hospitalization and deaths from the disease, the Johnson & Johnson vaccine is perhaps one of the most preferred choice of vaccines out there after Pfizer, Moderna, and AstraZeneca. The vaccine only requires one dose and does not need to be stored frozen, unlike its mRNA counterparts.
Earlier in March of this year, Denmark, Finland, and Norway announced that they have discontinued the use of the vaccine due to a possible link between the Johnson & Johnson and a rare blood clot disorder.