Vaccine manufacturers Pfizer and BioNTech have shown that its vaccine against the coronavirus disease (COVID-19) delivered an overall efficacy of 90.7 percent, an official from the Food and Drug Administration (FDA) said on Monday, Dec. 13.

During a Laging Handa press briefing, FDA Director-General Eric Domingo said that this was based on the clinical trial data that was submitted to them by Pfizer-BioNTech when it applied for an Emergency Use Authorization (EUA).

Domingo explained that the active ingredient in the vaccine that will eventually be used for kids aged 5 to 11 is identical with the one that is used on adults but comprises a different formulation and concentration and will be injected in smaller doses.

He added that the vaccines may likely be on a two-dose schedule which is the same as the protocol currently being followed in the United States, Europe, Canada and Australia.

"Ginagamit po siya as two doses. Ang initial schedule po is three to four weeks apart. Titingnan po ito ng vaccine experts at sila po yung magsasabi sa atin kung ano yung magiging schedule (It is used as two doses. The initial schedule is three to four weeks apart. Vaccine experts are examining this and they will be the ones to tell us the schedule)," Domingo said.

"Yung data na sinubmit sa atin titingnan po yan ng experts natin para mapili kung ano yung pinakamaganda sa atin na interval kung three weeks or four weeks or eight weeks. Parang katulad nung mga bakuna dati like Astrazeneca nung una pinayagan natin na 4 weeks and then nakita natin na mas maganda kung eight to 12 weeks after (Our experts are analyzing the data submitted to us to determine the best interval if it's three weeks, or four weeks, or eight weeks. It's like the Astrazeneca vaccine we first allowed a four-week interval but then we saw that it's better to have it eight to 12 weeks after)," he added.

With regard to the safety of the vaccine, Domingo stated that so far they have not seen any unusual signals of severe adverse events and that mostly mild side effects were recorded much like with other COVID-19 vaccines. He said that even during the eventual rollout of the vaccine, continuous monitoring will still be conducted to identify any unusual effect early on.