The United States has authorized this Friday the “immediate” resumption of the use of the vaccine by Janssen, the Belgian subsidiary of Johnson & Johnson (J&J), after its administration was practically suspended ten days ago due to several cases of thrombosis in women.
The decision was made by the U.S. Food and Drug Administration (FDA), the regulatory body, shortly after an advisory committee from the Centers for Disease Control and Prevention (CDC) advised it. same Friday.
“We have concluded that the known and potential benefits of the (Johnson & Johnson) COVID-19 vaccine outweigh its known and potential risks in people 18 years of age or older,” the acting FDA director said at a news conference. Janet Woodcock. “We are confident,” he added, “that this vaccine continues to meet our safety, efficacy and quality standards.”
Advisory Committee Scientists Suggest Vaccine Risk Advisory Addresses Women Under 50
At the same press conference, Dr. Peter Marks, a senior FDA official, explained that the resumption has “immediate” effect, although in practice it will be effective this Saturday morning. He also explained that people who opt for the J&J vaccine will be provided a paper warning about its potential risks.
Scientists from the CDC’s Advisory Committee on Immunization Practices (ACIP) suggested that the advisory say that women under 50 should be aware of possible thrombi from the vaccine.
Suspension of vaccination
The US recommended on April 13 to suspend the administration of the J&J serum, after six cases of cerebral thrombosis were detected in women under 48 years of age, of which one died.
Until this Friday the CDC had documented fifteen confirmed cases in vaccinated with J&J in a wider range of ages and with a total of three deaths. During the ACIP session, which lasted six hours, the scientists considered four options when updating the recommendation.
The alternatives ranged from completely discouraging its use to recommending it for all ages and genders, to warning women under 50 of possible risks of cerebral thrombosis or suggesting its administration only to adults over that age.
Most of the patients who developed thrombi after being immunized are in their 30s, although there have been cases in women between 18 and 59 years old. All but two of those affected were under 50 years of age.
15 cases of thrombi and three deaths
During the ACIP session, Dr. Tom Shimabukuro, the CDC’s head of vaccine safety, explained that among those 15 patients, seven are still hospitalized, of which four are in intensive care units. He specified that thirteen were between 18 and 49 years old, and twelve of them developed cerebral thrombosis, although many had clots in other parts of the body.
The initial symptom was headache, which usually began six days after being vaccinated, although, as time passed, the patients developed nausea, vomiting, abdominal pain, weakness on one side of the body, difficulties speaking, loss of consciousness and spasms, detailed the doctor.
Shimabukuro noted that seven of the women were obese, two had hypothyroidism, two had high blood pressure, and two were taking contraceptives. It is not clear at this time if any of these factors could contribute to increasing the risk of developing thrombi.
For now, 8 million doses of J&J have been injected in the US, whose administration has practically been paused in the country after the recommendation of last day 13.
Shimabukuro said there could be potential cases in men, which are currently being studied. Specifically, the scientist mentioned a 25-year-old patient who developed a clot when he participated in clinical trials of the vaccine.
In addition, representatives of J&J participated in the meeting, who assured that these cases are being taken “very seriously.”
The risks of Janssen and AstraZeneca
At the virtual meeting, Dr. Michael Streiff, an expert in thrombi at the Johns Hopkins University School of Medicine, pointed out that, according to the data he handles, the J&J and AstraZeneca serums cause clots in some people.
“So far it seems that there is a response with thrombi when receiving an adenoviral vector vaccine against SARS-Cov-2,” detailed Streiff, who stressed that at the moment the reason for this reaction is not clear.
Both the J&J and AstraZeneca vaccines, which apparently have also caused cases of thrombi in Europe, have been developed through the modification of an adenovirus, unlike others such as those of Pfizer and Moderna, which have used a technology based on in messenger RNA.
The US has granted emergency use authorization to Pfizer, Moderna and J&J sera, while AstraZeneca has not yet applied for such permission.
Links found in Europe
Three days ago, the European Medicines Agency (EMA) found a “possible link” between the development of very rare blood clots and the J&J vaccine, but confirmed that the balance between benefit and risk of this preparation remains “positive”.
After two weeks of investigations into the cases detected in the US, the EMA decided to add a warning of the possible risk, very small, of developing blood clotting to the vaccine package insert, but continues to recommend its use in the European Union (EU).