November 24, 2020 /
Bio ValleyBIOON/ -- At present, the COVID-19 epidemic overseas is still spreading rapidly. According to Baidu's "Real-time Data on the Novel Coronavirus Pneumonia Epidemic"
Big DataReport, as of 12:00 on November 24, 2020, the global cumulative confirmed cases exceeded 59.53 million, with over 1.4 million deaths.
Recently, there have been frequent breakthroughs in the development of COVID-19 vaccines, with several vaccines achieving significant progress, including
Pfizer/BioNTech's mRNA vaccine BNT162b2 (95% efficacy), Moderna's mRNA vaccine mRNA-1273 (94.5% efficacy),
AstraZeneca/Oxford University’s adenovirus vaccine AZD1222 (efficacy rate: 60%-90%). It should be noted that
, although its efficacy is lower than that of the two aforementioned mRNA vaccines, AZD1222 can be stored under standard refrigeration conditions (2–8°C), whereas mRNA vaccines require storage and distribution at –70°C, which poses significant limitations.
Recently, AstraZeneca announced positive high-level results from the interim analysis of clinical trials evaluating the COVID-19 vaccine AZD1222, conducted in the UK and Brazil. The data showed that AZD1222 was highly effective in preventing COVID-19 (the primary endpoint), and no hospitalizations or severe cases were reported among vaccinated participants. In
Clinical TrialIn the study, both immunization regimens demonstrated efficacy, with one regimen showing superior effectiveness. This interim analysis reported a total of 131 COVID-19 cases.
AZD1222 was jointly invented by the University of Oxford and its spin-off company, Vaccitech. It utilizes a replication-deficient chimpanzee adenovirus vector based on a weakened version of the common cold virus (adenovirus).
Carrier, this virus causes infection in chimpanzees and contains the SARS-CoV-2 spike protein's
Geneticssubstance. After vaccination, surface spike proteins are produced, stimulating the immune system to attack the SARS-CoV-2 virus.
According to AstraZeneca’s announcement, one immunization regimen (n=2,741) demonstrated 90% vaccine efficacy when AZD1222 was administered as a half-dose for the first dose, followed by a full dose at least one month later. Another immunization regimen (n=8,895) showed 60% vaccine efficacy when AZD1222 was administered as a full dose for both doses, separated by an interval of at least one month. A pooled analysis of both immunization regimens (n=11,636) yielded an average efficacy of 70%. All results were statistically significant (p≤0.0001). Additional data will continue to be accumulated, and further analyses will be conducted to refine efficacy estimates and determine the duration of protection.
An independent Data Safety Monitoring Board (DSMB) determined that the analysis met the primary endpoint: protection against COVID-19 starting 14 days or more after administration of two vaccine doses. No serious safety events related to the vaccine have been identified. AZD1222 was well tolerated in both immunization regimens.
AstraZeneca will now immediately prepare to submit data to regulatory authorities worldwide under conditional or early approval frameworks. The company will seek inclusion of AZD1222 on the World Health Organization’s (WHO) Emergency Use Listing to accelerate access to vaccine supplies in low-income countries. Meanwhile, a comprehensive analysis of the interim results will be published in a peer-reviewed journal.
AstraZeneca CEO Pascal Soriot stated, “Today marks a significant milestone in our fight against the COVID-19 pandemic. The efficacy and safety results of this vaccine have confirmed its high effectiveness in preventing COVID-19 and will have a direct impact on this public health emergency. Furthermore, the vaccine’s simple supply chain, our not-for-profit commitment, and our dedication to broad, equitable, and timely access mean that it will be affordable and available globally, with hundreds of millions of doses ready for distribution upon approval.”
This pooled analysis includes data from the UK COV002 Phase II/III trial and the Brazilian COV003 Phase III trial. More than 23,000 participants received one of two vaccination regimens (a half-dose/full-dose regimen or a two-dose full-dose regimen) or a control vaccine (meningococcal conjugate vaccine MenACWY) or saline, and are currently under evaluation. These global trials are assessing participants aged 18 years or older who are healthy or have stable underlying medical conditions, drawn from diverse ethnic and geographic populations.
Currently,
Clinical TrialsTrials are also underway in the United States, Japan, Russia, South Africa, Kenya, and Latin America, with plans to conduct further trials in other European and Asian countries. AstraZeneca expects to enroll a total of 60,000 participants globally.
AstraZenecaProduction is progressing rapidly, with production capacity expected to reach 300,000 doses in 2021. The AZD1222 vaccine can be stored, transported, and handled under standard refrigerated conditions (2–8°C/36–46°F) for at least six months and administered within existing healthcare facilities.
AstraZeneca will continue to collaborate with governments, multilateral organizations, and partners worldwide to ensure broad and equitable access to its not-for-profit vaccine during the COVID-19 pandemic. (Bioon.com)
Original Source: AZD1222 Vaccine Met Primary Efficacy Endpoint in Preventing COVID-19
