Senators are still doubting if the government can properly implement its COVID-19 immunization program even after officials have presented and explained how its rollout will be.

Senate President Vicente Sotto III said that while he was satisfied with the presentations during the Committee of the Whole's hearing on the government's vaccination plans on Monday, "the question remaining is the implementation."

"Kung 'yong presentation na ginawa nila ay magiging ganong kaganda ang implementation nila, eh (If their implementation would be as good as their presentation, then) we're out of trouble," Sotto, who leads the Senate Committee of the Whole's inquiry, said told radio DZBB on Tuesday when asked about his initial assessment on the government's immunization program.

"Napakaganda (The presentations were good). Eh sana ganon din ang implementation (I just hope the implementation would be the same)."

Sotto said some "kinks" have to be addressed so make sure that the inoculation program will be successful to achieve herd immunity against the novel coronavirus disease.

One of these, he said, was the national government's refusal to allow local government units and private institutions to take part in the vaccinations  and procure COVID-19 vaccines on their own.

Officials said vaccine makers are the ones who are not keen about directly supplying their products to LGUs and the private sector. They supposedly do not want to take responsibility due to possible risks pending the completion of the clinical trials.

At present, LGUs are purchasing supplies of the coronavirus vaccines under a tripartite agreement including the national government.

But according to Sotto, authorities failed to justify this position when asked what they plan to do once the pharmaceutical companies have agreed to sell their vaccines directly.

"Kung pumayag? Hindi sila nakasagot doon (What if they agreed? Officials were not able to answer)," he said.

Sharing Sotto's view, Senate Majority Leader Juan Miguel Zubiri raised concern that the inoculation will be delayed for months if the national government maintains this position.

"It's the implementation talaga (really). And the thing is, feeling ko madedelay tayo (I feel that we would be delayed)," Zubiri said in a separate interview over DWIZ, citing the need to wait for the arrival COVID-19 vaccines, its delivery to various parts of the country and its storage requirements.

"Kaya sabi namin ni Sen. Ralph , allow other sectors to participate. Para makatulong po sa gobyerno (So they they can help the government)," he said.

The government plans to roll out the immunization program in February this year, with vaccinations to starting by it third or fourth week, said vaccine czar Carlito Galvez Jr.