The Johnson & Johnson vaccine hiatus was lifted on April 23, 2021. SOPA Photographs / Mild Rocket by way of Getty Photographs Two vaccines – the Johnson & Johnson vaccine within the US and the AstraZeneca vaccine in Europe – have been linked to elevated threat uncommon sort of blood clot. Researchers are learning the causes of those clots and are beginning to provide you with solutions. Dr. Mousumi Som, professor of drugs at Oklahoma State College, explains what these uncommon clots are and the way they type after individuals get vaccinated. 1. What are blood clots? A small variety of individuals in the US have developed harmful blood clots after receiving the Johnson & Johnson vaccine. The clots have primarily occurred within the brains of individuals and, satirically, are related to a low platelet rely. Usually, platelets assist an individual cease bleeding when they’re injured. You probably have a reduce or harm, the physique responds by sending out platelets which act as a short lived patch. The patch attracts different platelets they usually stick collectively to cease blood loss. Since platelets usually assist the clotting course of, this mixture of low platelets and excessive clotting makes these clots medically uncommon. These particular sorts of clots – referred to as cerebral venous sinus thrombosis – though uncommon, have an effect on about two to 5 individuals per million per 12 months and are probably deadly with out therapy. Vaccines should not usually a set off for any such clot. 2. Who has these clots? As of April 24, 2021, of the 8 million individuals vaccinated with the Johnson & Johnson vaccine in the US, roughly 16 individuals have developed these blood clots. The clots occurred six to 13 days after vaccination, and the bulk had been in girls aged 18 to 48. On April 26, 2021, information experiences indicated that a minimum of one man had developed a clot. The person is in his 30s and was hospitalized with a clot in his leg about two weeks after receiving the Johnson & Johnson vaccine. Well being officers in Europe have additionally reported that the AstraZeneca vaccine – a COVID-19 vaccine licensed and permitted in Europe however not in the US – has triggered round 200 circumstances of low platelet clotting. You will need to observe that the Johnson & Johnson vaccine and the AstraZeneca vaccine use a innocent sort of virus referred to as adenovirus to supply directions to the human physique on the best way to create an immune response to COVID-19. That is referred to as a viral vector vaccine. The truth that each vaccines use a viral vector and that they’re each related to blood clots has led many well being specialists to consider that the clotting issues of the 2 vaccines could share the identical mechanism. 3. Why do girls have extra clots than males? At this level, docs nonetheless do not know what makes girls extra prone than males, or what exposes an individual to those clots. These clots can happen, though hardly ever, in individuals who don’t get the vaccine. Scientists know that ladies are thrice extra more likely to develop any such clot with out receiving the vaccine. Many researchers consider this is because of contraception or different hormone substitutes that ladies take. 4. Why can vaccines trigger blood clots? Researchers consider this particular low platelet clotting is just like a response some individuals expertise when they’re given a blood thinner referred to as heparin, referred to as heparin-induced thrombocytopenia. Medical doctors generally use heparin to skinny an individual’s blood within the occasion of a coronary heart assault or blood clot when blood move must be restored. However some individuals expertise the other response, and their blood finally ends up clotting extra as an alternative. This occurs as a result of the physique triggers an undesirable immune response after receiving heparin. In these sufferers, heparin attaches to a product launched from platelets referred to as platelet issue 4. When this occurs, the immune system sees mixed platelet issue 4 and heparin as an issue, so it creates antibodies in response. . These antibodies bind to the heparin and platelet issue 4 complicated, and the physique – which now thinks it must restore an harm – causes extra clotting whereas utilizing much more platelets. This leads to a low platelet rely noticed in these sufferers. When docs appeared on the blood of sufferers who developed clots after receiving the Johnson & Johnson or AstraZeneca vaccine, it appeared so much just like the blood of individuals with a low platelet clotting response to heparin. This has led scientists and docs to consider that the identical course of may result in these clots brought on by each vaccines. This text is republished from The Dialog, a nonprofit information website devoted to sharing concepts from educational specialists. It was written by: Mousumi Som, Oklahoma State College. Learn extra: Johnson & Johnson COVID-19 vaccine restart: Physician explains why the advantages far outweigh the dangers No, vaccine uncomfortable side effects do not let you know how effectively your immune system will shield you from COVID- 19 Mousumi Som operates within the State of Oklahoma College Well being Sciences Heart. She acquired funding from Eli Lilly and NIAID for drug-related analysis into COVID remedies. She is affiliated with the Nationwide Board of Osteopathic Medical Examiners and the Osteopathic Founders Basis. .