Medical experts in the UK now suggest that doctors should consider this rare disease in anyone who has constant symptoms up to a month after the vaccine. Blood clots can occur in different parts of the body, such as in the brain (cerebral venous veinombosis or CVST) or in the abdomen (idiopathic splanchnic venous thrombosis). These antibodies can also bind to platelets and activate them by causing them to clump together and trigger clotting. Clots can clog important blood vessels and the disease can be fatal, although some treatments improve the chances of survival. It`s possible, Nicolai says, that in rare cases, a vaccine is accidentally injected into a vein — as was the case in previous mouse studies that found that the adenovirus could bind to platelets. If this is the case, many cases of VITT could be prevented by having vaccinators first take a small amount of fluid with the syringe at the injection site to look for blood before pressing the plunger to administer the vaccine. This is already a common practice in some countries, and Denmark has included it in its official guidelines for the administration of COVID-19 vaccines. Because your blood can`t form clots, low platelet counts can lead to bleeding problems. Platelets (white) are fragments of cells that promote the formation of clots.
Source: Lennart Nillson, Boehringer Iingelheim International As with all vaccines, the EMA will continue to monitor the safety and efficacy of the vaccine and provide the public with the most up-to-date information. The PRAC found that blood clots occurred in the veins of the brain (thrombosis of the cerebral venous sinuses, CVST) and abdomen (splanchnic venous thrombosis) and arteries, as well as low platelet counts and sometimes bleeding. Concern has built up about a small but growing number of cases of a rare but serious blood clotting disorder linked to the Johnson & Johnson coronavirus vaccine. As a result, the Centers for Disease Control and Prevention (CDC) approved in mid-December the unanimous decision of their advisory committee to give a preferential recommendation to the Pfizer-BioNTech and Moderna vaccines. Based on current information on vitt, there is no evidence that blood clotting could occur more than four weeks after vaccination. However, blood clotting is possible months after COVID-19 for patients who have had long hospital stays, have undergone surgery, are immobilized, or have a history of underlying health conditions such as obesity, diabetes, or blood clots. This is variable depending on the patient and the duration of the disease. Coronavirus COVID-19 blood clot vaccine vitt hematology Patients who develop blood clots as a result of a COVID-19 infection usually have severe COVID-19 disease (hospitalized in the intensive care unit), respiratory failure, require large amounts of oxygen or have other underlying conditions. Other risks underlying blood clots include patients with a history of blood clots or an inherited blood clotting disorder. Those who have high blood pressure, diabetes, are obese or have cancer are also more at risk. The EMA Safety Committee (PRAC) concluded today that unusual blood clots with low platelets should be listed as very rare side effects of Vaxzevria (formerly AstraZeneca COVID-19 vaccine).
Dr. Thomas said people who take the drug heparin to prevent blood clots may have an increased risk of bleeding disorders due to COVID-19 or the AstraZeneca vaccine. To diagnose TTS, healthcare professionals perform blood tests, including a D-dimer test. If blood tests show that TTS is suspected or probable, a CT scan may be performed. A possible factor affecting the safety of adenoviral vaccines is how they are administered. COVID-19 vaccines are given as injections into the muscle, but if the needle punctures a vein, the vaccine could enter the bloodstream directly. Leo Nicolai, a cardiologist at the Ludwig-Maximilians-Universität München, and colleagues found in a mouse study that platelets clump together with the adenovirus and are activated when the Oxford-AstraZeneca vaccine is injected into the blood vessels, but not when injected into the muscle.11 As COVID-19 transmission resumes in the community, people over the age of 50 are evaluating the benefits of vaccination against the virus compared to the very rare risk of blood clotting induced by the AstraZeneca vaccine. Others believe that the culprit could be the adenovirus itself. Previous work has shown that adenoviruses can bind to platelets and trigger their depletion in mice7. It`s conceivable that these mice would also have developed blood clots if they had been observed longer, says Maha Othman, who studies blood clotting at Queen`s University in Kingston, Canada, and was the lead author of the study.
Hematologist and blood researcher Dan Thomas of the University of Adelaide said blood clots can move around the body if the circumstances that produced the clotting exceeded the factors that dissolved the clots. .