The AstraZeneca US Phase III trial of AZD1222 demonstrated a statistically significant vaccine efficacy of 79% in preventing symptomatic COVID-19 and 100% in preventing severe disease and hospitalizations. This interim safety and efficacy analysis was based on 32,449 participants who accrued 141 symptomatic cases of COVID-19. The trial had a 2:1 randomization of vaccine to placebo.
The vaccine was well tolerated and the independent data safety monitoring board (DSMB) identified no safety concerns related to the vaccine. The DSMB conducted a specific review of thrombotic events as well as cerebral venous sinus thrombosis (CVST) with the assistance of an independent neurologist. The Safety Committee found no increased risk of thrombosis or events characterized by thrombosis among the 21,583 participants who received at least one dose of the vaccine. Specific searching for cerebral venous thrombosis (CVST) found no events in this trial. Ann Falsey, Professor of Medicine at the University of Rochester School of Medicine, US, and co-lead principal investigator of the trial, said: “These findings reconfirm previous results seen in the AZD1222 trials in all adult populations. , but it’s exciting to see similar efficacy results in people over 65 for the first time. “This analysis validates the AstraZeneca COVID-19 vaccine as a much-needed additional vaccination option, offering confidence that adults of all ages can benefit from protection against the virus.” Mene Pangalos, executive vice president of Biopharmaceutical Research and Development, said: “These results add to the growing body of evidence showing that this vaccine is well tolerated and highly effective against all severities of COVID-19 and in all age groups. We are confident that this vaccine can play an important role in protecting millions of people around the world against this deadly virus. We are preparing to submit these findings to the US Food and Drug Administration and to roll out millions of doses across the US should US Emergency Use Authorization be granted. AstraZeneca will continue to analyze the data and prepare for the primary analysis to be submitted to the US Food and Drug Administration for Emergency Use Authorization in the coming weeks. In parallel, the primary analysis will be submitted for publication in a peer-reviewed journal. Among participants in the interim analysis, approximately 79% were White/Caucasian, 8% Black/African American, 4% Native American, and 4% Asian, and 22% of participants were Hispanic. About 20% of participants were 65 years of age or older, and about 60% had comorbidities associated with an increased risk of severe COVID-19 progression, such as diabetes, severe obesity, or heart disease. This US Phase III trial led by AstraZeneca included two doses administered four weeks apart. Previous trials have shown that an extended interval of up to 12 weeks demonstrated greater efficacy, which was also supported by immunogenicity data. This evidence suggests that giving the second dose more than four weeks apart could further increase effectiveness and speed up the number of people who can receive their first dose. The vaccine can be stored, transported and handled under normal refrigerated conditions (2-8 degrees Celsius or 36-46 degrees Fahrenheit) for at least six months and administered without the need for preparation within existing healthcare settings. AstraZeneca continues to collaborate with governments, multilateral organizations and collaborators around the world to ensure broad and equitable access to the vaccine on a non-profit basis during the pandemic. |
A phase 3 study in the USA showed that the AstraZeneca vaccine is 100% effective for severe cases, 79% effective in preventing COVID symptoms, includes people over 60, and was shown to be safe.
The findings may help restore confidence in the vaccine that was recently lost after more than a dozen countries, mainly in Europe, suspended use of the shot following reports of rare blood clots. Most of those countries resumed using the AstraZeneca vaccine late last week, after the European Medicines Agency, which regulates medicines in the European Union, analyzed data and declared the vaccine safe and effective.
The US government has pre-ordered 300 million doses of the AstraZeneca vaccine, according to the Washington Post. Three vaccines, from Pfizer, Moderna and Johnson & Johnson, have already received emergency use approval.
"We are confident that this vaccine can play an important role in protecting millions of people around the world against this deadly virus," Mene Pangalos, executive vice president of Biopharmaceuticals Research and Development at AstraZeneca, said in a news release from the company. company. "We are preparing to submit these findings to the US Food and Drug Administration and to roll out millions of doses across the US should US emergency use authorization be granted."
Involving more than 32,000 participants, the U.S. trial of the AstraZeneca vaccine was the largest test to date for the shot. The findings also showed that the vaccine offered 80 percent protection for older people, who had not been as well represented in previous studies.
"These findings reconfirm previous results seen in trials [of the AstraZeneca vaccine] in all adult populations, but it is exciting to see similar efficacy results in people over 65 for the first time," said co-lead principal investigator Ann Falsy. , professor of medicine at the University of Rochester School of Medicine, said in the company’s news release.
Still, the results may not make much difference in the United States, where vaccine experts have noted that the AstraZeneca vaccine is different.
"It’s clear that more questions have been raised about the AstraZeneca vaccine than about any of the other vaccines now authorized in the U.S.," said Dr. Arnold Monto, acting chair of the Vaccines and Biologics Advisory Committee. Related from the FDA, which authorizes all vaccines. in the United States, he told CNN.
"It feels different, and it felt different even before the blood clot confusion," Dr. William Schaffner, liaison member of the CDC’s Advisory Committee on Immunization Practices, told CNN.
As for reports of rare clotting problems, "it’s hard to unring that bell," Dr. Paul Offit, a member of the FDA advisory committee, told CNN. "Once people are scared, it’s hard to stop caring for them."
Even if AstraZeneca received emergency approval from the FDA, the vaccine is unlikely to be available before May, The New York Times reported.
AstraZeneca’s vaccine has already been approved in more than 70 countries, but authorization by U.S. regulators would boost the vaccine’s reputation globally, the Times said.
The provisional results announced Monday were based on 141 cases of COVID-19 that had appeared in volunteers. Two-thirds of the participants received the vaccine, with doses four weeks apart, and the rest received a saline placebo.
None of the volunteers who received the vaccine developed serious symptoms or had to be hospitalized, a major selling point for the shot. However, AstraZeneca did not reveal how many volunteers had developed severe COVID-19 or had to be hospitalized after receiving the placebo shot, for comparison.
