Use wechat scan QR code to share with friends and circle of friends_ blank" href=" https://news.163.com/news/search?keyword=%E5%BC%BA%E7%94%9F "> Johnson & Johnson's new crown < a target ="_ blank" href=" https://news.163.com/news/search?keyword=%E7%96%AB%E8%8B%97 "> vaccine < / a >, at the same time, we began to investigate 6 cases of < a target =" in women aged 18 to 48_ blank" href=" https://news.163.com/news/search?keyword=%E8%A1%80%E6%A0%93 "> thrombosis < / a > report. One died and the other was hospitalized in critical condition. < / P > < p > as of Monday, there were 6.8 million people in the United States_ blank" href=" https://news.163.com/news/search?keyword=%E6%8E%A5%E7%A7%8D "> vaccinated with Johnson & Johnson vaccine, except for the above six cases, no other serious adverse reactions were reported. < p > < p > both AstraZeneca vaccine and Johnson & Johnson vaccine use < a target = "_ blank" href=" https://news.163.com/news/search?keyword=%E8%85%BA%E7%97%85%E6%AF%92 "> adenovirus < / a > vector. Prior to this, AstraZeneca vaccine subjects also had a very similar thrombosis, which was widely stopped by EU countries. Is adenovirus vector the original sin of thrombosis? < / P > < p > < b > doubts about the safety of adenovirus vaccine < / b > < / P > < p > six American women suffered from a rare cerebral venous sinus thrombosis within two weeks after being vaccinated with the Johnson & Johnson vaccine, which hindered the discharge of blood from the brain. Dr. Anne Schuchat of the Centers for Disease Control and Prevention said the results were similar to those of a stroke. < / P > < p > experts have yet to determine the extent to which the J & J vaccine causes thrombosis. But before that, European AstraZeneca vaccine subjects also had cerebral venous sinus thrombosis. Last month, European regulators concluded after investigation that this was a side effect of AstraZeneca vaccine. < / P > < p > according to European researchers, the AstraZeneca vaccine causes excessive immunity in the human body and activates platelets in the blood. Usually, when the human epidermis is injured, platelets are activated to promote blood coagulation and wound scab. However, platelets in some subjects were activated by the vaccine and formed blood clots in the body. < / P > < p > this thrombosis is unusual. First of all, the location of thrombosis is unusual, lower extremity venous thrombosis is more common, and cerebral venous sinus thrombosis and intestinal venous thrombosis after vaccination with AstraZeneca vaccine are very rare, especially cerebral thrombosis. < / P > < p > more importantly, thrombocytopenia was found in both AstraZeneca and Johnson & Johnson vaccine subjects. Platelets are the key to promote thrombosis. When platelets are low, it is not easy to form thrombosis. Dic (disseminated intravascular coagulation) is the most serious condition in clinic. Low platelet count is due to a large amount of consumption. < / P > < p > both Johnson & Johnson vaccine and AstraZeneca vaccine are adenovirus vector vaccines, which carry foreign DNA genome into cells. It is not clear whether adenoviral vector technology causes thrombosis. < / P > < p > German researchers speculate that the exogenous DNA of adenovirus vaccine may trigger the immune response of some people, or the existence of some personal biological characteristics of patients may make them more prone to over immunity. < / P > < p > it is not clear whether female subjects have a higher risk of thrombosis because there are too few samples to draw an exact correlation. Last week, some European countries restricted the elderly to receive the Oxford vaccine of AstraZeneca. The AstraZeneca vaccine has not yet been approved for use in the United States. < / P > < p > the US Food and Drug Administration recommends that people vaccinated with J & J vaccine in the past three weeks should contact a doctor if they have severe headache, abdominal pain, leg pain or shortness of breath. < / P > < p > in the first few days after vaccination, if you have mild headache and flu like symptoms, don't worry too much. This is the moderate defense produced by the human immune system. < / P > < p > at a news conference on Tuesday, Forsey, chief medical adviser of Biden administration, stressed that the immune reaction will occur within a short time after vaccination. In all six cases, thrombosis was found within 6 to 13 days after vaccination. If the patient has been vaccinated for one or two months, it is "meaningless" to worry about the problem of thrombosis. < / P > < p > the U.S. Food and Drug Administration and the Centers for Disease Control and prevention have recommended a suspension of J & J vaccination, and states have followed the advice. < / P > < p > at a news conference on Tuesday, U.S. federal officials said it might only take a few days for the government to review six case reports. A team from the U.S. Centers for Disease Control and prevention is expected to discuss the issue at a meeting on Wednesday Eastern time. < / P > < p > on Tuesday, Johnson & Johnson said in a statement that it had found a rare thrombus and thrombocytopenia in the subjects, "we have been reviewing these cases with European health authorities" and "we have decided to take the initiative to delay the delivery of vaccines in Europe.". < / P > < p > public health experts in the United States and Europe emphasize that for most people, the benefits of the new crown vaccine far outweigh the risks.