Ad5-nCoV

Convidicea is a viral vector vaccine similar to AstraZeneca's AZD1222 and Gamaleya's Gam-COVID-Vac which are also in Phase III clinical trials for COVID-19.[5] Some health officials say Ad5-nCOV can be stored in less extreme cold conditions compared to mRNA vaccines.[6] CanSino's trials in Chile,[4] Mexico,[7] and Pakistan[6] requires one dose compared to other vaccines which require 2 doses.

In early 2020, Chen Wei led a joint team of the Institute of Biotechnology, the Academy of Military Medical Sciences and CanSino Biologics to develop AD5-nCOV. According to the Chinese state media, the team registered an experimental COVID-19 vaccine for Phase I trial in China on 17 March 2020 to test its safety. The trial was conducted on 108 healthy adults aged 18 to 60 in two medical facilities in Wuhan, Hubei province.[8]

In April, a headline by China's official Xinhua News Agency proudly read that with Ad5-nCoV China "is the first to enter Phase 2 clinical trials" in the world regarding COVID-19 vaccine candidate.[9] The Phase II trial results were published in the peer-reviewed journal Lancet on 20 July 2020 and noted neutralizing antibody and T cell responses based on statistical analyses of data involving 508 eligible participants.[10] In September, Zeng Guang, chief scientist of the Chinese Center for Disease Control and Prevention said the amount of COVID-19 antibodies in subjects from the Phase I trials remained high six months after the first shot. Zeng said the high levels of antibodies suggested the shots may provide immunity for an extended period of time, although Phase III results were still required.[11] On September 24, CanSino began Phase IIb trials on 481 participants to evaluate the safety and immunogenicity of Ad5-nCoV for children ages 6–17 and elderly individuals ages 56 and above.[12]

In August, China's National Intellectual Property Administration issued the country's first COVID-19 vaccine patent to CanSino.[13]

On 16 May 2020, Canadian Prime Minister Justin Trudeau announced Health Canada had approved Phase II trials to be conducted by the Canadian Center for Vaccinology (CCfV) on the COVID-19 vaccine produced by CanSino. Scott Halperin, director of the CCfV said the vaccine would not be the only one going into clinical trials in Canada, and any potential vaccine would not be publicly available until after Phase 3 is complete.[14][15] If the vaccine trials were successful, then the National Research Council would work with CanSino to produce and distribute the vaccine in Canada. Halperin had hoped the clinical trials would begin as early as within two weeks, provided that the trial would get approval from an ethics board.[15] In August 2020, the National Research Council disclosed the vaccine had not been approved by Chinese customs to ship to Canada, after which the collaboration between CanSino and the Canadian Center for Vaccinology was abandoned.[16]

In September, CanSino began a Phase I trial in China with 144 adults to determine the safety and immunogenicity of the vaccine to be administered as a nasal spray, in contrast with most COVID-19 vaccine candidates which require intramuscular injection.[17]

In August, Saudi Arabia confirmed it would begin Phase III trials on 5,000 people for Ad5-nCoV in the cities of Riyadh, Dammam, and Mecca.[18]

In October, Mexico received the first batch of the vaccine for Phase III trials on 10,000 to 15,000 volunteers. Phase III trails were to be performed in Chihuahua, Durango, Nuevo León, Jalisco, Aguascalientes, Michoacán, Guerrero, Oaxaca, Morelos, Quintana Roo, Veracruz, Puebla, Hidalgo and Mexico City and began during the first week of November.[19][20]

In September, Russia's NPO Petrovax began Phase III trials on 500 volunteers,[3] which Petrovax later received approval from the government to expand to 8,000 more volunteers.[21][22]

In September, Pakistan began Phase III trials on 40,000 volunteers as part of a global multi-center study.[2] As of December, about 13,000 volunteers have participated in trials of Ad5-nCoV, with each volunteer receiving a payment of $50. The Washington Post reported that volunteers who were recently interviewed all spoke on the condition of anonymity, citing hospital officials' instructions that their identities be kept confidential. Javed Akram, vice chancellor of University of Health Sciences, Lahore and a member of Pakistan's national science task force on the coronavirus said there has been no adverse events with respect to the trials so far.[6] In February 2021, data released from late stage trial in Pakistan which included 30,000 participants, the vaccine has shown to have a efficacy of 100% at preventing severe disease related to COVID-19 while 74.8% effective at preventing symptomatic cases. Globally the efficacy rate was 90.98% at preventing severe cases and 65.7% at preventing moderate cases of COVID-19.[23]

In November, Chile approved Phase III trials on 5,200 volunteers to be managed by University of La Frontera and including centers from Araucanía, Los Ríos, Los Lagos and Metropolitan regions. The Chile trials require only one dose of the vaccine.[4][24]

In December, Argentina's Fundación Hupedes began Phase III trials in 11 health centers in the metropolitan area of Buenos Aires and Mar del Plata.[25]

In November, CanSino said it would begin interim analysis of Phase III results when 50 infection cases are found.[1]

On June 25, China approved Ad5-nCoV for limited use by the military for a period of one year. In a statement by CanSino, "Ad5-nCoV is currently limited to military use only and its use cannot be expanded to a broader vaccination range without the approval of the Logistics Support Department".[28]

On 5 February 2021 CanSino applied to Mexican health regulator Cofepris to authorize use of its vaccine, which would be administered in a single dose.[29]