What is the Ad5 Vaccine? (COVID-19) Russia-China

What is the Ad5 Vaccine?

Ad5-nCoV is the first novel coronavirus vaccine for COVID-19 in a clinical trial in China. The vaccine candidate is built upon CanSinoBIO’s adenovirus-based viral vector vaccine technology platform.

The CanSino Biologics Ad5-nCoV vaccine candidate is a genetically engineered vaccine candidate with the replication-defective adenovirus type 5 as the vector to express SARS-CoV-2 spike protein.

The new Ad5 vectored COVID-19 vaccine evaluated in the phase 1 trial is the first to be tested in humans. It uses a weakened common cold virus (adenovirus, which infects human cells readily but is incapable of causing disease) to deliver genetic material that codes for the SARS-CoV-2 spike protein to the cells. These cells then produce the spike protein and travel to the lymph nodes where the immune system creates antibodies that will recognize that spike protein and fight off the coronavirus.

On May 22, 2020, the Ad5 vectored COVID-19 vaccine was reported in a study to be tolerable and immunogenic at 28 days post-vaccination. Humoral responses against SARS-CoV-2 peaked at day 28 post-vaccination in healthy adults, and rapid specific T-cell responses were noted from day 14 post-vaccination. Our findings suggest that the Ad5 vectored COVID-19 vaccine warrants further investigation.

On June 29, 2020, media sources reported China's military has received the 'green-light' to use a COVID-19 vaccine candidate developed by its research unit, and CanSino Biologics after clinical trials proved it was safe and somewhat efficient.'

On July 20, 2020, a study published in The Lancet reported the Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles are safe and induced significant immune responses in the majority of recipients after a single immunization during a phase 2 study.

The primary endpoints for immunogenicity were the geometric mean titers of specific ELISA antibody responses to the receptor-binding domain and neutralizing antibody responses at day 28. The primary endpoint for safety evaluation was the incidence of adverse reactions within 14 days. All recruited participants who received at least one dose were included in the primary and safety analyses.

On August 11, 2020, China has granted its first COVID-19 vaccine patent according to the National Intellectual Property Administration. The patent was submitted for application on March 18, 2020.

CanSino Biologics Inc. is an innovative biopharmaceutical company dedicated to exploring the best solutions to the prevention of diseases through cutting edge research & development, advanced manufacturing, and commercialization of innovative vaccine products for human use worldwide.

CanSino Biologics was established in Tianjin, China in 2009. Inclusive of the COVID-19 vaccine, they are developing a number of vaccines including 13 for infectious diseases.

Ad5-nCoV Vaccine Indication

Ad5-nCoV is indicated to prevent COVID-19 disease, which is caused by SARS-CoV-2 coronavirus.

Ad5-nCoV Vaccine Dosage

Recombinant novel coronavirus vaccine (Adenovirus type 5 vector): This study did a dose-escalation, single-center, open-label, non-randomized, phase 1 trial of an Ad5 vectored COVID-19 vaccine in Wuhan, China. Healthy adults aged between 18 and 60 years were sequentially enrolled and allocated to one of three dose groups

(5 × 1010, 1 × 1011, and 1·5 × 1011 viral particles) to receive an intramuscular injection of vaccine.

Ad5-nCoV Vaccine News

• August 17, 2020 - Russia’s Petrovax has started a late-stage clinical trial of a COVID-19 candidate vaccine from CanSino Biologics. Inc.

• July 20, 2020 - The Lancet published 'Immunogenicity and safety of a recombinant adenovirus type-5-vectored COVID-19 vaccine in healthy adults aged 18 years or older: a randomized, double-blind, placebo-controlled, phase 2 trial. The Ad5-vectored COVID-19 vaccine at 5 × 1010 viral particles is safe, and induced significant immune responses in the majority of recipients after a single immunization.

• July 11, 2020 - Chinese vaccine developer CanSino Biologics announced it is in talks with Russia, Brazil, Chile, and Saudi Arabia to launch a Phase III trial of its experimental COVID-19 vaccine.

• June 29, 2020 - China's military has received permission to use a COVID-19 vaccine candidate Ad5-nCoV which was developed by its research unit and CanSino Biologics after clinical trials proved it was safe and somewhat efficient.

Ad5-nCoV Vaccine Clinical Trial

Clinical Trial NCT04341389: A Phase II Clinical Trial to Evaluate the Recombinant Vaccine for COVID-19 (Adenovirus Vector) (CTII-nCoV) - Last updated on May 18, 2020.

• A Randomized, Double-blind, Placebo-controlled Phase II Clinical Trial to Evaluate the Safety and Immunogenicity of the Recombinant Novel Coronavirus Vaccine (Adenovirus Vector) in Healthy Adults Aged Above 18 Years.

• This Phase 2 clinical trial is designed to evaluate the immunogenicity and safety of Ad5-nCoV which encodes for a full-length spike (S) protein of SARS-CoV-2. Start date of April 12, 2020.

• This major Chinese study (ChiCTR2000031781) involves the co-sponsor of the Institute of Biotechnology, Academy of Military Medical Science. Research sites include the Hubei Provincial CDC in Wuhan, Hubei Province, China. Other participants include the Jiangsu Province CDC, the Hubei Provincial CDC, and the Zhongnan Hospital.

• 603 volunteers were recruited and screened for eligibility between April 11 and 16, 2020. 508 eligible participants (50% male; mean age 39·7 years, SD 12·5) consented to participate in the trial and were randomly assigned to receive the vaccine (1 × 1011 viral particles n=253; 5 × 1010 viral particles n=129) or placebo (n=126). In the 1 × 1011 and 5 × 1010 viral particles dose groups, the RBD-specific ELISA antibodies peaked at 656·5 (95% CI 575·2–749·2) and 571·0 (467·6–697·3), with seroconversion rates at 96% (95% CI 93–98) and 97% (92–99), respectively, at day 28.

• Both doses of the vaccine-induced significant neutralizing antibody responses to live SARS-CoV-2, with GMTs of 19·5 (95% CI 16·8–22·7) and 18·3 (14·4–23·3) in participants receiving 1 × 1011 and 5 × 1010 viral particles, respectively. Specific interferon γ enzyme-linked immunospot assay responses post-vaccination were observed in 227 (90%, 95% CI 85–93) of 253 and 113 (88%, 81–92) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively. Solicited adverse reactions were reported by 183 (72%) of 253 and 96 (74%) of 129 participants in the 1 × 1011 and 5 × 1010 viral particles dose groups, respectively.

• Severe adverse reactions were reported by 24 (9%) participants in the 1 × 1011 viral particles dose group and one (1%) participant in the 5 × 1010 viral particles dose group. No serious adverse reactions were documented.

Chinese Clinical Trial Registration: ChiCTR2000030906: Phase I clinical trial of recombinant new coronavirus (2019-COV) vaccine (adenovirus vector)

• A single-center, open, and dose-increasing phase I clinical trial of recombinant coronavirus vaccine (adenoviral vector) in healthy adults between 18 and 60 years of age ​​

• ​​The trial assessed the safety and ability to generate an immune response of different dosages of the new Ad5-nCoV vaccine in 108 healthy adults between the ages of 18 and 60 years who did not have SARS-CoV-2 infection. Volunteers were enrolled from one site in Wuhan, China, and assigned to receive either a single intramuscular injection of the new Ad5 vaccine at a low dose (5 × 1010 viral particles/0·5ml, 36 adults), middle dose (1×1011 viral particles/1.0ml, 36 adults), or high dose (1.5 x 1011 viral particles/1.5ml, 36 adults).

• The researchers tested the volunteers' blood at regular intervals following vaccination to see whether the vaccine stimulated both arms of the immune system: the body's 'humoral response' (the part of the immune system that produces neutralizing antibodies which can fight infection and could offer a level of immunity), and the body's cell-mediated arm (which depends on a group of T cells, rather than antibodies, to fight the virus). The ideal vaccine might generate both antibody and T cell responses to defend against SARS-CoV-2.

• The vaccine candidate was well tolerated at all doses with no serious adverse events reported within 28 days of vaccination. Most adverse events were mild or moderate, with 83% (30/36) of those receiving low and middle doses of the vaccine and 75% (27/36) in the high dose group reporting at least one adverse reaction within 7 days of vaccination.