Former United States President Donald Trump suggested that booster shots for COVID-19 are not medically necessary as these are just part of the money-making operation of vaccine manufacturers.

In a phone interview with Maria Bartiromo of Fox Business Wednesday, Trump claimed that pharmaceutical companies like Pfizer are just out to make huge profits from these vaccines.

The former president said what this all sound like to him is a cash-generating venture for Pfizer. "Think of the money involved here. An extra shot that is tens of billions of dollars," Business Insider quoted him as saying.

Trump also pointed out that he was "proud" to have received the coronavirus vaccine while claiming without any basis that when he stepped down from the White House, the virus "virtually disappeared."

Trump did not mince words about Pfizer's "profiteering," calling the New York-based pharmaceutical giant's operation "crazy" and Pfizer Chief Executive Officer Albert Bourla as "the guy that runs" the company.

The U.S. government announced Wednesday that it would start offering booster shots late next month and recommend that most people be administered with a third dose 8 months after their second shot of Pfizer's and Moderna's vaccines.

Officials from the Centers for Disease Control and Prevention (CDC), U.S. Food and Drug Administration (FDA), along with White House COVID-19 adviser Dr. Anthony Fauci, announced the booster plan.

However, the announcement was made without the CDC and FDA publicly saying they had fully evaluated giving a third dose to the 100 million fully-immunized Americans by the end of 2021.

Meanwhile, many Twitter users felt the former commander in chief's comments could worsen the current pandemic situation, since they might discourage unvaccinated people from getting inoculated.

According to Twitter user David French, Trump's comments are "close to the worst thing he could say."

For Jan Wolfe, he feels that Trump has cast doubts on COVID-19 vaccines, just months after he called the vaccines "medical miracle."

But Kerry Eleveld was more brutal, saying Trump is still not content with the half-million Americans he and his GOP backers "doomed to die pre-vaxx."

U.S. health officials concluded that booster shots are necessary to strengthen the body's immunity to COVID-19 as the Delta variant spreads.