According to Pfizer's CEO, people who received the company's version of the COVID-19 vaccine would most likely need a booster shot within a year.
Albert Bourla made the announcement in a two-week-old interview with CNBC reporter Bertha Coombs, which was made public Thursday.
"Likely scenario 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," Bourla said.
The Pfizer CEO also stated that an annual shot would most likely be needed.
According to Bourla, certain illnesses, such as polio, need just one vaccine injection, while the flu requires a shot every year.
"The COVID-19 virus looks more like the influenza virus, than the polio virus. The duration of immunity was unknown until yesterday," Bourla said in the interview recorded on April 1.
Bourla was referring to data published earlier this month that showed the Pfizer and BioNTech COVID-19 vaccine is 91% effective for at least six months after a second dose.
Pfizer stated at the time that the results indicated that the mRNA vaccine is 95.3% effective against severe COVID-19 as defined by the FDA and 100% effective against severe disease as defined by the Centers for Disease Control and Prevention.
According to the company, 12,000 participants have been followed up on after their second dose to ensure that the vaccine is safe for up to six months.
The vaccine was also found to be 100% effective against the variant discovered in South Africa, according to the study. However, only 800 people took part in the study of the B1.351 variant.
Pfizer and BioNTech previously revealed in February that they will begin testing a third dose of the COVID-19 vaccine to protect people from new variants.
Other studies have also shown the vaccines' efficacy. A study from the CDC published at the end of March showed both the Pfizer and Moderna shots were highly effective, with 90% efficacy after two doses.