AstraZeneca Vaccine Linked to Rare Blood Clots, EU Regulators Concludehttps://arstechnica.com/science/2021/04/blood-clots-are-very-rare-side-effects-of-astrazeneca-vaccine-eu-regulators/European medical regulators on Wednesday concluded that there is a strong link between AstraZeneca’s COVID-19 vaccine and life-threatening conditions involving the unusual combination of blood clots and low levels of blood platelets.
As such, the conditions should be listed as a “very rare side effects” of the vaccine, according to the European Medicines Agency, a regulatory agency of the European Union.
https://www.ema.europa.eu/en/news/astrazenecas-covid-19-vaccine-ema-finds-possible-link-very-rare-cases-unusual-blood-clots-low-bloodThe conclusion was based on the EMA’s in-depth review of 86 blood-clotting events among around 25 million people vaccinated with the AstraZeneca vaccine in Europe and the UK. Of the 86 blood-clotting events (0.00034%), 18 people died (0.00007%). Most—but not all—of the cases occurred in women under the age of 60.
The events reviewed by the EMA included 62 cases of cerebral venous sinus thrombosis (CVST), a rare form of stroke in which a clot prevents blood from draining out of the brain. The remaining 24 cases involved splanchnic vein thrombosis, which involves blood clots in the veins that drain blood from the abdomen.
Beyond the 86 cases examined, the EMA estimated that there’s a reporting rate of one case of the side effect in 100,000 people vaccinated.Regulators noted that this unusual combination resembles a condition called heparin-induced thrombocytopenia or HIT.
HIT develops because of an aberrant immune response. In a reaction to heparin that’s not completely understood, some patients’ immune systems produce antibodies that attack a common platelet protein called Platelet Factor 4, or PF4. This in turn triggers platelet activation and pro-clotting particles, leading to HIT.
https://pubmed.ncbi.nlm.nih.gov/20059332/Though the EMA solidified the connection between the clots and the AstraZeneca vaccine, it still recommends using the vaccine. Along with the EMA, the World Health Organization still strongly contends that the benefits of the AstraZeneca vaccine’s effectiveness at preventing deadly COVID-19 infections strongly outweigh the risks of extremely rare blood-clotting conditions.
The new side effect listing in the EU will only make things more difficult for AstraZeneca. And it’s also likely to cast a shadow over the Johnson & Johnson COVID-19 vaccine, which is authorized in the US and elsewhere and uses the same design as AstraZeneca’s vaccine. Both vaccines use an adenovirus vector.
A potential pitfall of adenovirus-based vaccines is that adenoviruses can also bind to platelets and cause problems. In fact, some pre-pandemic data has suggested that adenoviruses can activate platelets and lead to low platelet counts. But the connection between this and the mechanism causing the blood clotting in vaccinees needs far more data to be understood.
https://www.spandidos-publications.com/10.3892/mmr.2013.1805https://www.sciencedirect.com/science/article/pii/S0006497120417847?via%3DihubOf the approximately 4.5 million people who have received the Johnson & Johnson vaccine worldwide, there have been three reported cases of blood-clotting events similar to those seen in people given the AstraZeneca vaccine, Arlett said. These numbers are “extremely small,” he emphasized. “This is, however, under close scrutiny... I think it would be fair to say there’s intensive monitoring of this issue across the vaccines.”
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People Who Got the Moderna COVID-19 Vaccine Say They Have More Side Effectshttps://www.theverge.com/2021/4/7/22371665/covid-vaccine-side-effects-moderna-pfizerThe anecdotal reports are true: people who get the Moderna COVID-19 vaccine say they have more side effects than people who get the Pfizer / BioNTech shots, according to new data published this week in
JAMA.
https://jamanetwork.com/journals/jama/fullarticle/2778441The study analyzed reports collected through a Centers for Disease Control and Prevention program called v-safe. It’s a text message-based program designed to track side effects in vaccine recipients. For the first week after each vaccine dose, people who enroll are prompted to fill out a daily survey about any symptoms, like fatigue or arm pain
Over 3,600,000 people who got their first dose of a COVID-19 vaccine before February 21st enrolled in v-safe and checked in at least once. Around 70 percent of those people said they had some kind of injection site reaction, like pain or swelling, and half had a more generalized reaction like fatigue or chills. For both, people who got a Moderna shot were more likely to have a side effect — 73 percent had an injection site reaction, compared with 65 percent of people who had a Pfizer / BioNTech dose. Around 51 percent of Moderna recipients had full-body symptoms, compared with 48 percent of people who got Pfizer / BioNTech.
The gap widened after the second dose. About 1.4 million people completed those check-ins. Almost 82 percent of people getting their second Moderna shot had injection site pain versus just under 69 percent of people with Pfizer / BioNTech. Overall, 74 percent of people said they had general reactions after their Moderna shot, compared with 64 percent of people getting Pfizer / BioNTech. The biggest difference was for chills, which were experienced by 40 percent of people taking Moderna and only only 22 percent of people taking the Pfizer / BioNTech shot.
People over 65 were also less likely to have side effects than people under 65, regardless of which vaccine they received.
Overall, the side effects and frequency of side effects were similar to the ones seen in clinical trials testing these vaccines. The clinical trials gave researchers and doctors an accurate look at the types of side effects people can expect after they get their shots