People who received Pfizer or Moderna vaccines will likely need a third dose, according to company officials.

Albert Bourla, CEO of Pfizer, in an interview released Thursday said "Likely scenarios is there will likely be a need for a third dose somewhere between six and 12 months and then from there, there will be an annual vaccination."

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The head of Pfizer also said that an annual shot will likely be needed as well.

Medical experts say that, like the flu, the COVID-19 virus will never stop mutating, which is partially why a booster shot will likely be needed between nine to 12 months after people are initially vaccinated. 

"If I have to get it, I have to get it. It's no big deal for me," says Bill Goss, of Mohegan Lake.

Work has already begun on creating booster shots. Moderna officials say they hope to have theirs ready by the fall.

Officials from both Pfizer and Moderna say their vaccines are about 90% effective against the coronavirus for six months. But, since it's only been six months since their trial participants started to get vaccinated, they don't have the efficacy numbers beyond that.

So while the duration of immunity after vaccination is being studied, booster vaccines could be needed, as well as annual shots, similar to the flu shot. "Just like we take the flu vaccine every year, we kind of anticipated this to be in a similar pattern. What this vaccine is more than likely going to do is treat all those variants, just like the flu," says Dr. Azfar Chak, the chief of the Infectious Disease Department at Montefiore Nyack Hospital.

While some medical experts say it's very likely the vaccines are highly effective long after 6 months, both Pfizer and Moderna officials say they are monitoring their trial participants to see if there is a drop off in protection.

"If I have to get it, I have to get it. It's no big deal for me," says Bill Goss, of Mohegan Lake.

Work has already begun on creating booster shots. Moderna officials say they hope to have theirs ready by the fall.