(UPDATE) THE Department of Health (DoH) said on Thursday that the 5 million flu vaccines it ordered were due to arrive next month.

"The DoH is currently finalizing the procurement of the flu vaccines, with an estimated delivery time of August. The vaccination program for senior citizens will run until the end of the year," the DoH said in an online briefing with reporters, noting the arrival of the flu shots is timely for the onset of the wet season when people are vulnerable to the common cold and flu.

Rontgene Solante, an infectious diseases specialist, a former member of the Vaccine Expert Panel and lead convenor of the Raising Awareness on Influenza to Support Elderlies coalition, urged the quick rollout of flu vaccination, noting there was an underreporting of influenza deaths in the country.

Influenza, he said, can lead to severe complications, including a tenfold increased risk of heart attack and an eightfold higher risk of stroke in adults ages 40 and older. During flu season, patients with type 2 diabetes face a 74 percent higher risk of abnormal blood sugar levels, and hospitalized older adults can experience a 23 percent decline in functionality due to the flu.

The DoH said it was still processing data on influenza-like illnesses in the country.