Vietnamese president Nguyen Xuan Phuc's resignation, announced on Tuesday, comes as part of a major anti-corruption drive that has seen several ministers fired.

While eradicating corruption has been in the sights of Vietnam's leadership for years, attention in 2022 focused on graft during the pandemic.

So far, the drive has swept up ministers, civil servants and businessmen -- and it shows no sign of halting.

Here is what we know:

- How did Vietnam manage the pandemic? -

Vietnam closed itself to the world for almost two years before reopening in mid-March 2022.

While shut, Vietnam organised nearly 800 charter flights to bring citizens home from 60 countries and territories.

It initially garnered international plaudits for its efforts to contain the pandemic, but a huge outbreak swept through business hub Ho Chi Minh City in mid-2021 and spread across the country.

A strict lockdown saw much of the country unable to leave home for months, before infections were brought under control through widespread vaccination.

- So what went wrong? -

Although Vietnam repatriated its citizens, travellers faced exorbitant airfares and quarantine fees once they arrived.

Last year, the Ministry of Public Security said officials were able to skim tens of thousands of dollars from each repatriation flight.

Meanwhile, social media users began raising questions over government-sponsored testing kits from as early as 2020 after it emerged they were not -- as the state claimed -- World Health Organization-approved.

The so-called Viet A scandal, named after the semi-private firm that supplied the tests, saw officials bribed to supply hospitals and local communities with vastly overpriced Covid-19 test kits.

The scam is estimated to have netted some $172 million for Viet A -- $34 million of which was allegedly ploughed straight back into the further bribing of officials.

- Who was involved? -

The anti-corruption drive has seen more than 130 government officials and businesspeople detained.

Pham Binh Minh and Vu Duc Dam were removed from their positions as deputy prime ministers earlier this month over alleged wrongdoing.

Phan Quoc Viet, director-general of Viet A, as well as health minister Nguyen Thanh Long and Hanoi mayor Chu Ngoc Anh, have been arrested in connection with bribery.

The repatriation flight scandal has seen the arrest of deputy foreign minister To Anh Dung and several senior diplomats.