The government is having a tough time on how to safely transport the Russian-made coronavirus vaccines to the country without compromising its stability.

President Duterte recognized the importance of ensuring the potency of the coronavirus vaccines during the delivery to the country, a day after the arrival of the Sputnik V doses was pushed back to next month.

Addressing the nation Monday, April 28, the President admitted that the lack of direct flights between Russia and the Philippines led to the delay in the arrival of the Sputnik V vaccines.

The vaccines, which required extremely cold chain storage, had to pass through a number of places before reaching the country, he said.

"'Yung dynamics sa delivery ng mga bakuna, ‘yong sabi na hirap tayo sa mga pagdala kasi wala namang eroplano na makuha natin direct Russia–Philippines, China–Philippines (On the dynamics of the delivery of the vaccines, we have difficulty with the delivery because we could not get a plane to fly directly Russia-Philippines, China-Philippines)," Duterte said.

"Maraming daanan, it’s transshipment. Dito lang hanggang Hong Kong tapos ilipat. So that’s why sabi niya nahihirapan tayo minsan mag-tailor ng saan natin ipadaan sa madaling panahon and that the integrity o ‘yong bisa ng bakuna is protected (It had to pass many places, it's transshipment. It will travel to Hong Kong and then transfer to another place. So that's why he said we are having difficulty to sometimes tailor the place where we will transport the vaccines at the soonest possible time and that the integrity or potency is protected)," he said.

The country was supposed to receive the initial batch of 15,000 doses of Sputnik V vaccines developed by Russia's Gamaleya Research Institute last Wednesday but the delivery did not push through due to logistical concerns. The original arrival date was last Sunday but was postponed to Wednesday.

The government is aiming to work out the delivery problems and ensure the arrival of the vaccines by next month. More than 400,000 Sputnik V vaccines are also expected to be shipped to the country by May.

The Sputnik V vaccines require storage with a temperature of -18 degrees Celsius and below. The Russian-made vaccines, taken in two doses 21 days apart, have shown over 90 percent efficacy rate in the clinical studies.

The Philippines and Russia have earlier committed to working together in fighting the pandemic, particularly in vaccine cooperation. The President earlier offered to get vaccinated with the Russian vaccine to his trust and gratitude but later changed his mind. The 76- year-old leader now prefers to wait for coronavirus vaccine developed by China's Sinopharm.