The figures, released by the Ministry of Transport, doubles its worst-case-scenario forecast in February, which was a 23 percent drop to 61.2 million passengers.
The revised forecast follows passenger numbers remaining scant in April due to travel restrictions imposed by the government to curb the spread of the novel coronavirus.
The number of foreign passengers this month has fallen by 99 percent year-on-year to 21,000; and that of cargo transport, 93 percent to 64,000 tons.
Vietnam’s aviation industry has been severely hurt by the coronavirus pandemic, and a recovery will only come at the end of the year, the ministry said.
The state-owned Vietnam Airlines is the most hurt among local carriers, with revenues dropping 26 percent year-on-year to VND19.2 trillion ($819 million) in the first quarter.
If the pandemic persists until the fourth quarter, the airline estimates a loss of VND19.6 trillion ($836 million) this year after years of making profit.
Last year, Vietnam’s air passengers served by both domestic and foreign airlines reached 78.3 million, up 11.8 percent year-on-year.
All provinces and cities in Vietnam have been allowed to increase the frequency of flights, trains and buses starting Thursday following the government's social distancing relaxation.
The number of active Covid-19 patients in the country remains at 45, not to mention six relapse cases, including one who has left Vietnam.
The Covid-19 pandemic has reached 210 countries and territories with a reported death toll of almost 197,000.