According to Pfizer CEO Albert Bourla, anyone who completed the two-dose protocol for the company’s Chinese Communist Party (CCP) Virus or COVID-19 vaccine would likely require a third shot within a year.

“A likely scenario is that there will be likely a need for a third dose, somewhere between six and 12 months, and then from there, there will be an annual revaccination,” Bourla told CNBC’s Bertha Coombs in a CVS Health Live event “Race to Vaccinate” aired on Thursday, April 15.

Bourla also said that it is “extremely important to suppress the pool of people that can be susceptible to the virus.

”The Johnson & Johnson vaccine needs two doses, while the Pfizer and Moderna vaccines only needs one.”

Following multiple warnings of blood clots in millions of Johnson & Johnson vaccines, the U.S. health agencies recommended a pause in vaccinations this week.

Johnson & Johnson CEO Alex Gorsky proposed a few weeks ago that CCP Virus shots would be needed once a year, equivalent to seasonal flu shots.

According to Fox News, Pfizer has recently released new results showing that its vaccine was highly successful up to six months after the second dose, based on data from over 12,000 people who took part in a late-stage trial.

The company started research in February to see if a third shot could better defend against evolving strains of the virus, such as the troubling strain discovered in South Africa. There were nine CCP Virus cases in the placebo community, according to the recently published data from 800 participants in South Africa.

“But all of that needs to be confirmed. And again, the variants will play a key role,” Bourla said. “We need to see what would be the sequence, and for how often we need to do that, that remains to be seen.”

“There are vaccines that’s like polio that one dose is enough, there are vaccines like a pneumococcal vaccine that one dose is enough for adults, and there are vaccines like flu that you need every year,” he added. “The COVID virus looks more like the influenza virus than the poliovirus.”

Dr. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, told a House subcommittee hearing on April 15 that the U.S. monitors diseases in people who have been completely vaccinated.

There have been 5,800 such “breakthrough diseases” among the 77 million people in the United States who have been vaccinated, according to Walensky, with 396 people requiring hospitalization and 74 people dying.

According to the Washington State Department of Health, further study will help establish trends among the breakthrough events, such as if a form of the CCP Virus) caused the infection.

“Finding evidence of vaccine breakthrough cases reminds us that, even if you have been vaccinated, you still need to wear a mask, practice socially distancing, and wash your hands to prevent spreading COVID-19 (CCP Virus) to others who have not been vaccinated,” said Dr. Umair Shah, Washington state’s secretary of health.