The U.S. suspension of the Johnson & Johnson vaccine after recording 6 cases of blood clots has left those planning to receive the vaccine confused and raised concerns that this could cause hesitation over covid-19 vaccination.
U.S. halts use of Johnson / Johnson vaccine
The implementation of johnson&johnson’s (J&J)one-dose Covid-19 vaccine was halted on April 13 when regulators announced they were reviewing rare cases of blood clots after receiving it. The move could prompt thousands of people expected to get the J&J vaccine this week to find an alternative.
The Food and Drug Administration (FDA) and the U.S. Centers for Disease Control and Prevention (CDC) both recommend halting the distribution of the J&J vaccine after recording 6 cases of cerebral vein sinus thrombosis (CVST).
Illustration: Reuters
Symptoms are noted in women between the ages of 18-48 and appear 6-13 days after the J&J. vaccine injection. “Among cases of coaalysis in the U.S., one person has died and one patient is in critical condition,” said Peter Marks, head of the FDA’s Center for Biological Research and Evaluation.
However, stopping the use of the J&J vaccine in the US when there are only a few cases of blood clots has raised questions about over-reactions.
Speaking at the White House on April 13, Dr. Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases, said that the CDC and FDA have acted “with extreme caution” and stressed that the decision to recommend stopping the use of the J&J vaccine is only temporary.
“I don’t think they made the decision in a hurry,” Mr. Fauci said.
Despite this, the move left those planning to get the J&J vaccine confused and raised concerns that it could cause hesitation over covid-19 vaccination.
Earlier, 15 million J&J vaccines were damaged due to production errors at a factory. In Colorado, three mass vaccination points stopped using the J&J vaccine last week after 11 people reported symptoms of nausea and dizziness after receiving the vaccine.
For regulators, halting the use of the J&J vaccine has made it difficult to meet the urgent need for vaccines during the pandemic. When investigating the issue, U.S. officials must also try to maintain public confidence in the vaccination program. The suspension of J&J vaccination shows that regulators are taking potential issues seriously, but if they can’t find an answer yet, it could make people more concerned about vaccinations.
Link between J&J vaccine and cerebral vein sinus thrombosis
Cerebral vein sinus thrombosis (CVST) is a condition in which blood clots are formed in the veins and sinuses of the brain. This is a rare form of a stroke. In the general population, this symptom occurs in about 5 out of 1 million people. Symptoms of CVST include headache, blurred vision, convulsions, and loss of body control.
However, there are a number of factors that cause regulators to pay attention to cases of CVST after a single dose of J&J. Mr. Marks explained that, patients with blood clots also have tinglet reduction, the condition of tinglets in the blood decreases to very low levels, leading to bleeding and bruising. The combination of blood clots and low tinglets prevents patients from using common anti-coaculation treatments such as heparin, a blood thinner. That’s why health officials want to halt J&J.J. vaccinations until concerns can be investigated and give new guidance if necessary.
In addition, another factor is the cases of blood clots that occur in young women, who usually do not face a high risk of suffering from this disease.
The suspension of the J&J vaccine has been reminiscent of many European countries suspending all or part of the Covid-19 AstraZeneca vaccination program due to fears of blood clots. In March, the European Medicines Regulator (EMA) halted distribution of the AstraZeneca vaccine before allowing it to continue. Later, regulators concluded the AstraZeneca vaccine did not increase the risk of blood clots.
“This is a safe and effective vaccine. The benefits of vaccines in protecting people from the risk of dying and hospitalization from Covid-19 are far greater than the possible risks,” EMA Executive Director Emer Cooke said at a press conference in March.
Both the AstraZeneca vaccine and the Johnson /Johnson vaccine are based on modified adenovirus vectors. Adenovirus is a separate virus designed to provide DNA instructions to cellsto make the mutable protein of SARS-CoV-2, the virus that causes Covid-19.
Nearly 7 million people in the U.S. who have been vaccinated with the J&J. Vaccine AstraZeneca are still under review and have not yet begun distribution in the U.S., even though the country’s government has purchased millions of doses of the vaccine.
The link between the J&J vaccine and symptoms of cerebral vein sinus thrombosis has not yet been clarified, but Vox has made several assumptions.
“Mutant proteins are produced using instructions from vaccines,” said Robert Brodsky, Director of hematological division at Johns Hopkins University. In some cases, mutating proteins can trigger the response of the immune system. That immune response can also damage the tinglets, causing symptoms such as blood clots.
In addition, if a spike in a protein can trigger this reaction, it is likely that the virus is intact that can also activate CVST in vulnerable people.
Rare complications that create major public health challenges
The Covid-19 vaccine has been tested on tens of thousands of people in clinical trials, and all three licensed vaccines in the U.S., Moderna, Pfizer/BioNTech, and Johnson & Johnson have all been proven safe, with levels of side effects being mild to medium.
Health workers prepare J&j’s Covid-19 vaccine shots in Detroit on April 12. Photo: AP
But as the number of people taking part in vaccine trials increased from thousands to millions, rare complications began to appear.
That happened to Pfizer/BioNTech after the vaccine was distributed to the market. Some people after vaccination experience a severe allergic reaction to the Pfizer vaccine. Similar problems also appeared with the Moderna vaccine. In January, the CDC estimated that the rate of allergic reactions to the Pfizer/BioNTech vaccine was 11.1 per 1 million vaccinations, while the rate of the Moderna vaccine was 2.5 per 1 million vaccinations.
Health officials have revised the vaccination process to screen people with a history of severe allergies. They also asked the person after vaccination to stay for 15 minutes for monitoring, as most allergic reactions occur during that time period.
Regulators can add screening criteria for people at higher risk for blood clots before getting the J&J vaccine.
It’s too early to say whether regulators will do the right thing when it comes to halting J&J vaccinations. Studying potential vaccine issues can boost people’s confidence in vaccinations, but can also cause confusion and fear of complications, making more people more vigilant.
What about those who have received the J&J vaccine?
Dr Fauci said that, for those who had received the J&J vaccine more than a month ago, they didn’t need to worry. However, those who have recently received the J&J vaccine and begin to have symptoms associated with cerebral sinus thrombosis should inform their doctor. “6-13 days after vaccination will be the time of symptoms,” Mr Fauci said.
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