Science & Technology

A single dose of the Chinese Ad5-nCoVCOVID-19 vaccine is safe and effective in Phase 3 trials

  • Ad5-nCoV vaccine developed in China is 57.5% effective against symptomatic COVID-19 (new coronavirus infection) Phase 3 randomized controlled trial analysis shows that it is infected 28 days after vaccination and is 91.7% effective against severe COVID-19.
  • No serious vaccine-related adverse events were reported, and most adverse events were mild to moderate, including injection site pain, headache, drowsiness, and generalized myalgia.
  • Research is underway to determine the long-term safety and efficacy of the vaccine, as well as its efficacy against delta, omicron, and other variant of concern. Additional research is underway on the potential need for booster doses.

A single dose of Ad5-nCoV (Convidecia), a COVID-19 vaccine developed in China 57 57..Five% Effective against symptomatic COVID-19 91.7% effect on severe According to a phase 3 randomized controlled trial published in, COVID-19 disease begins 28 days after vaccination. Lancet..

This report shows that Ad5-nCoV is safe, no significant vaccine-related adverse events or deaths have been reported among study participants, and that the vaccine elicits a strong antibody response.

CanSino Biologics, Inc. Developed by Beijing Institute of Technology and Beijing Institute of Technology, Ad5-nCoV is a single-dose viral vector vaccine that can be stored at 2 ° C to 8 ° C. The vaccine has been approved for emergency use in 10 countries, including Argentina, Chile, Mexico and Pakistan, where this current clinical trial was conducted. In Russia, which also participated in this clinical trial, regulatory review is underway.

“Our study suggests that a single dose of Ad5-nCoV is very effective for serious illness, which can cause people to become seriously ill or need hospitalization. Preventing COVID-19 may help relieve the tremendous tension that COVID-19 has brought to the healthcare system around the world. In addition, vaccines can help relieve serious illness after a single injection. Because it is effective, it can help improve access to vaccinations, especially in low- and middle-income countries, as it can be more difficult to reach people with two initial vaccinations. Of course. ” Said Dr. Scott Harperin of the University of Dalhausie, Canada, the lead author of the study.

The ongoing trial will begin on 22 September 2020, with 36,982 adults aged 18 years and older enrolled by 15 January 2021, of which 36,727 will be randomized to vaccine or vaccine across 66 enrollments. I received a placebo injection. Sites of research centers in Argentina, Chile, Mexico, Pakistan, and Russia.

Researchers conducted an efficacy analysis after reaching the protocol threshold for symptomatic COVID-19 confirmed in 150 laboratories (RT-PCR positive) 28 days after injection on January 15, 2021. did. Effectiveness cohort. The researchers reported 105 positive COVID-19 cases out of 10,590 participants in the placebo group and 45 positive COVID-19 cases out of 10,660 participants in the vaccine group, 28 days after vaccination. Brought 57.5% effectiveness in.

Efficacy for severe illness is 91.7% 28 days after vaccination, and severe illness indicates severe systemic illness, respiratory failure, evidence of shock, severe acute kidney injury, liver, or neurological. It was defined as the minimum of clinical signs at rest. Dysfunction or admission to the ICU. There were no COVID-19-related deaths among vaccinated individuals.

Ad5-nCoV was well tolerated and produced high levels of anti-RBD and neutralizing antibodies, as reported in Phase 1 and Phase 2 trials.

Most of the side effects, such as pain at the injection site, drowsiness of the headache, and generalized myalgia, were mild to moderate and occurred within 7 days of the injection. Study participants had no reports of thrombosis or thrombocytopenia.

The authors warn that the efficacy analysis was performed on samples collected before January 15, 2021, so it does not include analysis of recent concerns of variants such as Delta and Omicron variants. doing.

“Further research is needed to determine the long-term efficacy and endurance of Ad5-nCoV and its efficacy against mutant strains of concern, including Omicron, which is rapidly overtaking Delta as the predominant strain worldwide. “Dr. Joan Langley said. Dalhousie University, Canada.

The authors note that additional secondary outcomes such as efficacy against asymptomatic infections and efficacy against PCR-negative and seroconversion-positive cases are also analyzed.

Additional ongoing studies are underway to investigate the relative efficacy of the single-dose and double-dose regimens of Ad5-nCoV.

The author notes the limitations of some further research. The survey was conducted in five countries, but the majority of the survey participants included in this analysis were from Pakistan (16,950 participants) and Mexico (13,559 participants). This is primarily due to the first launch on the Pakistan site on September 22, 2020 and the trial in Mexico on November 6, 2020. People with unstable medical conditions, pregnant people, and children were excluded from the study. Women and the elderly were also underestimated. Researchers adopted aggressive case-finding methods through weekly telephone and text message communications, but signs and symptoms were self-reported (confirmed through direct study visits), so all positive cases were Not included. Further research is underway to determine the long-term durability of Ad5-nCoV and its effectiveness against changing concerns.

In a linked comment, Dr. Richard Kennedy of the Mayo Clinic, USA, who was not involved in the study, said: SARS-CoV-2 There are still large parts of the world where vaccine development and production and access to vaccines remain restricted. Vaccine hesitation is also an obstacle to achieving high vaccination rates in some parts of the world. In addition to these challenges, the SARS-CoV-2 vaccine continues to reduce immunity and the emergence of mutants capable of various degrees of antigenic escape. Therefore, there is a clear and urgent need for the continued development, testing, and use of additional vaccines … This study provides important data to support the continued use of another adenoviral vector vaccine. .. Continued monitoring of this research population is needed to answer ongoing questions related to weakened immunity, duration of protection, the need for booster vaccination, and the ability to protect against new variants, including Omicron. .. “

Reference: “Final efficacy analysis, intermediate safety analysis, and immunogenicity of a single dose of recombinant novel coronavirus vaccine (adenovirus type 5 vector) in adults 18 years and older: international, multicenter, randomized. Randomization, double-blind, placebo control phase 3 trial “December 23, 2021 Lancet..
DOI: 10.1016 / S0140-6736 (21) 02753-7

This study was conducted by CanSino Biologics, Inc. And funded by Beijing Institute of Technology. A complete list of researchers and institutions is available in the dissertation.

A single dose of the Chinese Ad5-nCoVCOVID-19 vaccine is safe and effective in Phase 3 trials A single dose of the Chinese Ad5-nCoVCOVID-19 vaccine is safe and effective in Phase 3 trials

Back to top button