AD5-nCOV, trade-named Convidecia, is a single-dose viral vector vaccine for COVID-19 developed by CanSino Biologics. It conducted its Phase III trials in Argentina, Chile, Mexico, Pakistan, Russia, and Saudi Arabia with 40,000 participants.

In February 2021, global data from Phase III trials and 101 COVID cases showed that the vaccine had a 65.7% efficacy in preventing moderate symptoms of COVID-19, and 91% efficacy in preventing severe disease. It has similar efficacy to the Janssen vaccine, another one-shot adenovirus vector vaccine with 66% efficacy in a global trial. Convidecia is similar to other viral vector vaccines like AZD1222, Gam-COVID-Vac, and Ad26.COV2.S. Its single-dose regimen and normal refrigerator storage requirement (2° to 8 °C) could make it a favorable vaccine option for many countries. It is currently under evaluation for emergency use listing by the WHO.

A Phase I study published in The Lancet showed two doses of a nasal-spray version of Convidecia resulted in neutralising antibody responses similar to the existing one-dose injection.

Convidecia and the Pakistani version called Pakvac are approved for use by some countries in Asia, Europe, and Latin America. Production capacity for Ad5-NCov should reach 500 million doses in 2021. Manufacturing will take place in China, with filling and finishing of the vaccine additionally also taking place in Malaysia, Mexico, and Pakistan.