AstraZeneca Covid-19 Vaccine is Safe, 79% Effective in Late US Studies

The blow is already widely used outside the US. However, US studies reflect the largest tests of the vaccine to date and could boost confidence in its use following questions about its effectiveness and the serious problems of blood clotting in a very small number of people. in Europe that received the shot. US studies have not identified an increased risk of blood clotting.

AstraZeneca said participants aged 65 and over were 80% effective in the vaccine.

Concerns about blood clotting have led more than a dozen European countries, including Germany and Italy, to temporarily stop using the vaccine this month. Most resumed vaccination after European and British regulators re-approved the use of the vaccine, despite rare coagulation problems that did not prove to be related to the vaccine. Regulators said they cannot rule out a connection, but said the vaccine is an important weapon in preventing death and serious illness and that its benefits outweigh the potential risks.

Much is based on the global acceptance of AstraZeneca photography, which was co-developed with Oxford University and is the most widely used in many parts of the globe. The US Food and Drug Administration is expected to review the study data and may decide whether to authorize the use of the vaccine as early as next month.

Previous results of the shooting process in the UK and elsewhere have been criticized for the lack of elderly volunteers, who were later recruited into the trial for safety reasons. The United Kingdom and other countries have used the vaccine in people over the age of 55, but some countries initially withheld and shot only in younger age groups.

The US trial involved 32,449 participants over the age of 18 and approximately 20% were 65 years of age or older. The effectiveness of the vaccine was 100% in the prevention of severe diseases and hospitalizations, with similar results in all age groups and ethnicities.

The results of the UK study of the vaccine, launched late last year, showed a range of efficacy, between 62% and 90%. This range was difficult to compare with the results of US studies of rival vaccines, one from Pfizer Inc.

and BioNTech SE from Germany and another from Moderna Inc.

Both have been shown to be more than 90% more effective in US studies.

The results of US studies have not yet been reviewed by independent researchers. AstraZeneca said the analysis would be sent for publication in a peer-reviewed journal.

AstraZeneca said independent safety monitors performed a specific analysis of severe blood clotting or severe thrombotic events, based on study data, including a severe condition known as cerebral venous sinus thrombosis that was reported to be related to a very few deaths in Europe among people who have received the vaccine. The review was assisted by an independent neurologist. It did not find an increased risk of thrombosis among 21,583 participants who received at least one dose of vaccine, AstraZeneca said.

The US AstraZeneca vaccine study, which began recruiting volunteers in the US, Chile and Peru in August, was standardized to follow FDA guidelines, measuring the results of two doses every four weeks. AstraZeneca said the dose range – which Britain and other countries have done – could further increase the vaccine’s effectiveness.

The results of late US studies provide the closest comparison between the AstraZeneca vaccine and rival photos, which were first adopted in US clinical trials, showed that Pfizer and Moderna photos are more than 94% effective against symptomatic Covid-19.

Meanwhile, studies conducted by Oxford with the AstraZeneca-Oxford vaccine last year in the UK and Brazil have produced a confusing range of results, from 62% to 90%, depending on dose size and timing.

Real-world vaccination data, highly dependent on the UK. the mass launch has since shown that a single blow is about 70% effective and very effective in preventing death and hospitalizations. These results suggested that separating the two doses by approximately 12 weeks contributed to increased immunity, resulting in an efficacy of approximately 80% among people aged 70 years or older after the second stroke. British researchers said the result was similar to the results over 70 years of the Pfizer-BioNTech vaccine.

The developing world is relying heavily on the AstraZeneca-Oxford hit, with 3 billion doses promised to be unprofitable this year. But public health experts have been concerned about the complex results of studies last year, and AstraZeneca’s prolonged tension with European officials over extreme deficiencies in vaccine administration targets could permanently damage the vaccine’s reputation.

These factors and mistakes of AstraZeneca in its public and regulatory communications last year could impact perceptions on the US vaccine, said some AstraZeneca experts and analysts.

In late February, the US authorized Johnson & Johnson’s Covid-19 vaccine for the US market, bringing a third blow to the country’s vast supply chain. Single-dose shooting was generally found to be safe and 66.1% effective in protecting individuals against the development of moderate to severe cases of Covid-19 at least 28 days after vaccination, based on a study conducted in approximately 44,000 volunteers aged 18 and over.

The launch of vaccination in the US has faced supply and distribution challenges. But both production and photo management have increased in recent weeks. Now, about 2.5 million people in the United States are vaccinated daily on average, up from about 500,000 in early January.

But many people who want a vaccine cannot get one. AstraZeneca vaccine depots cannot be distributed in the United States until the shot is approved by the FDA.

Last week, the Biden administration announced plans to send 4 million doses of AstraZeneca vaccine stored in the United States to Canada in Mexico as a loan before the potential authorization. Officials said no agreement had been finalized.

The United States has said it has 7 million “deliverable doses” of the AstraZeneca vaccine. In total, the US has ordered 300 million doses of AstraZeneca-Oxford vaccine, including a contract for 200 million doses for the Department of Defense.

The US has quickly pursued vaccine production to meet domestic goals, including by encouraging production partnerships between vaccine manufacturers and accelerating funding to accelerate the production of ingredients and supplies.

AstraZeneca has built a global network of production partners, including Serum Institute of India, the world’s largest vaccine manufacturer, to meet its supply targets. Staged approvals, production deficiencies and export battles complicated the launch. The directors of AstraZeneca stated that they are solving problems in the supply chain and intend to finally fulfill the announced obligations.

Following reports of blood clotting in Europe, regulators said last week that they would add a warning to usage guidelines and patient information sheets for vaccine patients, healthcare providers and vaccine recipients to be looking for rare signs called thromboembolic problems – including a serious brain condition that caused a very small number of deaths in people who received the vaccine – and continued to support the shooting. But regulators have pointed out that there is no proven link between the vaccine and coagulation problems, which also occur naturally in the general population and, in many cases, in Covid-19.

Write to Jenny Strasburg at [email protected]