The United States Food and Drug Administration (FDA) limited the application of the Janssen covid-19 vaccine, manufactured by the Johnson & Johnson pharmaceutical company, due to the risk of developing thrombosis with thrombocytopenia syndrome (TTS) after the application of this biological.
The decision was announced on May 5, after studies were known that indicate the risk of developing this syndrome that produces “rare and life-threatening blood clots in combination with low levels of platelets in the blood”, one or two weeks after applying the vaccine.
“We have been closely monitoring the Janssen COVID-19 vaccine and the appearance of TTS after its administration and have used updated information from our safety surveillance systems to review the EUA,” said the director of the Center for Biological Evaluation and Research of Janssen. the FDA, Peter Marks.
The new recommendation is that this vaccine be applied to people over 18 years of age for whom other vaccines against covid are not accessible or are not clinically appropriate. As well as those people who would not otherwise receive another vaccine.
“The FDA has determined that the known and potential benefits of the vaccine for the prevention of COVID-19 outweigh the known and potential risks for persons over the age of 18 for whom other approved COVID-19 vaccines are not accessible or clinically appropriate,” they say.
Worldwide, the Janssen vaccine ranks as the fourth most applied. According to the data repository Our World in Data, some 18.6 million doses of this biological have been applied. In Nicaragua there are 993,600 doses that were donated by Spain in January 2022. However, it is unknown how many of these have already been applied to the population and to what age groups.
Three out of every million vaccinated reported thrombosis
The FDA report explains that the rate per million inhabitants who tend to develop thrombosis with thrombocytopenia syndrome associated with the vaccine is 3.23. Meanwhile, the probability of dying from this syndrome is 0.48. The factors that put a person at risk after receiving this vaccine are still unknown.
“The FDA also found that people with TTS can deteriorate rapidly despite prompt diagnosis and treatment, that TTS can have debilitating long-term health consequences, and that TTS has a high mortality rate,” explains the FDA. release.
The Jansen vaccine was authorized to be applied in the United States on February 27, 2021. From its first months of administration there were alarms about the cases of thrombosis identified in those who received this vaccine. This caused this country, the European Union and other nations to suspend the application of these doses for a time.
However, after a “comprehensive safety review,” the FDA and the US Centers for Disease Control and Prevention (CDC) concluded that the known and potential benefits of this vaccine outweighed the risks. “We are confident that this vaccine continues to meet our standards for safety, efficacy, and quality,” they said in April 2021.
In December of that year, the US health authorities recommended the use of Pfizer and Moderna vaccines as preferred over Johnson & Johnson’s Jansen.
Unlike the two most widely used vaccines in the world, Pfizer and Moderna, which use Messenger RNA, Janssen uses a deactivated adenovirus, that is, it contains a fragment of a modified virus that cannot cause covid-19, but it does “ it gives instructions to the body’s cells to mount an immune response.”
Initially, this vaccine is a single dose and it is recommended to receive a second dose as a booster from Pfizer or Moderna at two months.
