The Viral Factor is a 2012 Hong Kong-Chinese action film directed by Dante Lam and starring Jay Chou and Nicholas Tse.

The supporting cast includes Lin Peng, Michelle Bai, Andy On, Carl Ng, Liu Kai-chi and Elaine Jin, with action choreographed by Dante Lam and Chin Kar-lok.

IDC (International Defense Commission) agent Sean Wong (Andy On) and his team members are in Jordan on a dangerous mission to escort a scientist named Kenner Osama Muhammad, who has stolen a copy of the smallpox virus, to Norway.

It was later revealed that Sean has betrayed the team for his own agenda and shot his colleagues Jon Man (Jay Chou) and his girlfriend Ice (Michelle Bai).

The failed mission left Ice dead while Jon has a bullet lodged in his brain with no safe way to remove it and only two weeks to get his affairs in order before succumbing to permanent paralysis.

Elsewhere, Sean contacts an arms dealer called Tyler (Jared Robinson), and suggests to mutate the virus into a biological weapon, develop a vaccine and sell it to a corrupt pharmaceutical company.

On his flight to Malaysia, Jon meets Asian Centre for Disease Control and Prevention (ACDC) doctor Rachel Kan (Lin Peng), who was later abducted by Yeung after the plane landed.

Meanwhile, Yeung and his goons breaks into Rachel's house, who holds her mother hostage and forces her to get a Carnot virus sample from the ACDC headquarters.

The next day, while Yeung and Rachel are leaving the building after obtaining the virus sample, a security personnel triggers the alarm, causing a chase through the city.

During the chaos several ACDC guards and Yeung's partners are killed and Rachel is re-captured by Mark (Sammy Hung), Sean's right hand man working with Russell.

Working together, Jon and Yeung manages to hold off the corrupted police officers long enough for them to board a train to escape.

Yeung encounters Mark dumping Cheung-sing's body into the sea and kills him in a fit of anger before jumping off the ship to retrieve his daughter.

[8] Among them, the scene in a traffic jam was filmed at Jalan Raja Chulan, during long weekends and public holidays when fewer people would be in Kuala Lumpur.