Dr Ly Nguyen Le Anh, a former lecturer at the Military Technical Academy, said the outbreak is being contained and is not expected to spiral out of control.

His forecasting model uses data on efforts to control the disease and its infectivity.

But he said the data needs to be collected over several weeks to ensure accuracy since there are cases with long incubation periods, which means symptoms would only show up several days after a person contracts the virus.

The model takes into account three sources of infection, from close friends and family members, workplace and society and random infections due to close proximity, he said.

He then used techniques like computer simulations, differential calculus and functions to create the forecasting model.

A Covid-19 forecast model by mathematician Ly Nguyen Le Anh depicting the number of active cases (top) and daily new cases (bottom left) and total coronavirus tally in the new wave.

It forecasts that from July 8 to mid-July there will be few to no new cases, and by August 29 most mild and moderate cases will recover.

The incidence should peak this week, and the number of active patients should peak by around June 20 at 7,000-8,000.

"So far there has not been major variations in the data," Anh said.

"The number of infections is a bit higher than what the model suggests, but in general the disease is being contained."

If the current efforts are kept up, the number of new cases would gradually decline starting now, he said.

Anh is not the only one to attempt to simulate the trajectory of the Covid wave.

Last month several experts, including the head of the tropical diseases department at HCMC's Cho Ray Hospital, Le Quoc Hung, said most new cases would have already been contained through contact tracing, posing no infection threat and driving the number of cases down.

Referring to HCMC's recent decision to impose two weeks of social distancing, Anh said around three days’ data is required to see if outbreaks in the southern metropolis are "out of control."

Vietnam has had 4,549 cases in the five weeks since the fourth Covid-19 wave started.

Bac Giang and Bac Ninh have reported the largest numbers of infections, 2,424 and 879, followed by Hanoi with 416, including 93 in a hospital under lockdown, and HCMC with 227.