AstraZeneca’s vaccine faces thrombosis problem

Germany, France, Italy and Spain all have Stop vaccination With AstraZeneca Coronavirus disease After vaccination, someone reported a rare blood clot.

These moves by the four largest EU countries came after a pause in several smaller member states-marking a new crisis of confidence Affordable vaccines This is seen as the best hope for accelerating COVID-19 vaccination throughout developing countries.

Experts emphasize that there is currently no clear evidence that the vaccine is causing these blood clots, and the relevant cases are being investigated by regulatory agencies.But the latest worries predate this Scientist’s question About how the company Safety and effectiveness vaccine. AstraZeneca is expected to release the results of a large-scale clinical trial, which will determine whether the FDA authorizes the vaccine to be used in the United States.

The suspension of vaccination in Europe was caused by 3 reported hospitalized cases, including 1 patient who died. Norway, with Further deaths in a statement The European Medicines Agency (equivalent to the FDA’s regulatory agency) released on March 11 stated that among the 5 million people shot by AstraZeneca, a total of 30 cases of “thromboembolic events” or blood clots were in the EU.

EMA said: “There is currently no indication that vaccination has caused these diseases, but it has not been listed as a side effect of this vaccine.” “The position of the EMA Safety Committee is that … the benefits of the vaccine continue to exceed its risks, and the vaccine can continue to be used. .”

AstraZeneca said that there are a total of 37 reported cases of pulmonary embolism and deep vein thrombosis, both of which are caused by blood clotting, which is less than the expected incidence of the general population.

The company’s chief medical officer, Ann Taylor, said: “Currently in the European Union and the United Kingdom, approximately 17 million people have been vaccinated with our vaccine, and the number of blood clot cases reported in this group is a few hundred less than expected. .” statement Released on March 14.

The World Health Organization is Urge countries to continue to use vaccinesAt the same time, there is no evidence that it can cause blood clots. WHO experts will meet on Tuesday to discuss the blood clot report.

However, a few incidents stopped some countries. According to the German Health Minister Jens Spahn (Jens Spahn), there are 7 reports of rare diseases. Cerebral Venous Sinus Thrombosis (CVST), among 1.6 million people using AstraZeneca vaccine in Germany. The Paul Ehrlich Institute, part of the German Ministry of Health, said on Monday, worried According to reports, the disease is accompanied by abnormal bleeding and a small amount of platelets, forming a clot and preventing bleeding.

So far, the few cases seen in Germany are more than expected, but it may be a statistical blessing. “[T]He said that even if there is no causal relationship, the probability of such a statistical clustering of a result is actually very high. “Paul Hunter, a public health expert at the University of East Anglia, said in a comment published through the British Science Media Centre.

EMA will meet on Tuesday to discuss issues related to blood clotting and is expected to release its conclusions on Thursday. Given that COVID-19 cases have risen again in several EU countries, long-term vaccination interruptions will be a worrying prospect. Particularly shocking wave -Spread with more infectious variants.

Experts contacted by BuzzFeed News said that without knowing more patient cases, there is not enough evidence to draw a clear conclusion about whether the vaccine caused blood clotting. Orly Vardeny of the University of Minnesota said: “We want to know the age of the case, the previous medical history, and the conditions that may be predisposed to blood clots or bleeding,” said Orly Vardeny, a pharmacist who specializes in heart health. (Orly Vardeny) said.

“It may have nothing to do with the vaccine. If it is related to the vaccine and it is not seen everywhere, then the most likely explanation is the mass production problem.” John Moore, a virologist at the Weill Cornell School of Medicine in New York ) Conducted research on vaccine development, he told BuzzFeed News. (Some countries, Including Austria, Have Special stop vaccination AstraZeneca vaccine from a specific batch. )

The new concern is the latest result in a series of failures of AstraZeneca’s COVID-19 vaccine developed at the University of Oxford.As early as November, AstraZeneca claimed Press release The overall effective rate of its vaccine is 70%, and if given in a half dose in the first dose of two injections, the vaccine’s effectiveness can reach up to 90%.But many scientists Skeptical, Especially when pharmaceutical companies recognize that this system is Wrong dose calculation.AstraZeneca later increased the confusion by Change its interpretation From the dose itself to the lag between two doses, 90% efficacy is required.

It was hit even harder in February, when South African trials showed that the vaccine no effect Fight against the more contagious coronavirus spreading there. South Africa suddenly suspended its plan to use AstraZeneca vaccines and switched to vaccines produced by Johnson & Johnson and Pfizer/BioNTech.

Now, scientists are waiting Big trial The production of AstraZeneca vaccines in the United States and other countries/regions will be the basis for the company’s application to authorize the FDA to use the vaccine. But some experts want to know whether adding AstraZeneca vaccine to the vaccine library used in the United States will cause more problems? Anti-vaxxers may catch negative publicity Surround it to disrupt the broader vaccination campaign.

“Does it really have a niche market? Will it be trusted enough? Or will it have another headache?” Moore said.

Children’s Health Defense Organization Peddle misinformation with Conspiracy theory It has been about vaccines for many years highlight It is reported that several European countries are suspending the use of the vaccine.

In developing countries, especially in Africa, vaccines may bring huge changes Far behind. The Biden administration has been under pressure to donate produced doses of AstraZeneca vaccine to poorer countries. New York Times Report On March 11, at the same time, COVAX-a partnership formed by the World Health Organization, the Alliance for Epidemic Prevention Innovation and the Vaccine Alliance Gavi, aims to provide affordable vaccines to poor countries. Rely on the use of AstraZeneca vaccine Hundreds of millions of doses are provided throughout developing countries.

In response to the BuzzFeed news, a Gavi spokesperson said: “Safety is our biggest concern: We know that the national authorities and the World Health Organization are closely monitoring the situation, and the COVAX facility will follow their guidance and recommendations.” “Currently, there is no vaccine. Establish a causal relationship with individual thromboembolic events, and vaccines are still an important and effective public health tool to fight this pandemic.”

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