They are Nguyen Thi Anh Vien, Lam Quang Nhat, Hoang Quy Phuoc and Tran Duy Khoi.
Vien won eight gold medals at the recent SEA Games, and achieved three A standards to compete at the 2016 Rio Olympics in the women's 200m medley, 400m medley and 400m freestyle.
Nhat secured a B standard to swim at the Olympics next year in the men's 1,500m freestyle, Phuoc has two B standards in the men's 100m and 200m freestyle, and Khoi earned a B standard in the men's 200m medley.
"Nhat, Khoi and Phuoc aim to improve their achievements in Russia. It would be great if they can reach A standards at this event. We hope 18-year-old Vien, will make a splash in her favourite events," said Hung.
"I will forget about my SEA Games' achievements in Singapore. I try best to do well in Russia and then at the 2016 Olympics in Brazil," said Vien.
However, it will be a difficult task for Vien at the swimming world's biggest non-Olympic event.
According to the latest rankings from the World Swimming Federation, Vien ranks 20th in the women's 400m freestyle, 24th in the 400m medley and 29th in the 200m medley.
Vien's target in Russia is to get threw the qualifying rounds in her favourite events and earn another A standard for Brazil.
In preparation for the event, Vien and her coach Dang Anh Tuan have been training in the US.
Vien made it to No 14 in the world in the women's 400m individual medley last year, thanks to her one gold and two silver medals at the Youth Olympics, two bronzes at the Asian Games and strong performances at competitions in the US.
She also won three golds and one silver at the Asian Youth Games in China in 2013, and was voted Athlete of the Year in 2013 and 2014.
The championships will draw 1,028 athletes from 208 nations and territories, competing in diving, synchronised swimming, water polo and open swimming.
The 12 countries with the most participants are Australia, Brazil, China, France, Germany, Great Britain, Greece, Hungary, Italy, Japan, Russia and the US.
The event will be aired on VTV6.