(NewsNation) — Shares in some pharmaceutical and biotechnology companies, including those that manufacture vaccines, fell this week after President-elect Donald Trump announced he chose Robert F. Kennedy Jr. to be Secretary of the Department of Health and Human Services.

On Friday, Moderna, which produced COVID-19 vaccines, shares fell almost  7% after hitting their lowest level since April 2020, Reuters reports. Since Trump was announced the winner of the 2024 election, shares of Moderna went down about 30%. Pfizer, which also makes vaccines saw a 4.5% decrease on Friday as well, after the Wall Street Journal reported they dropped by 2.5% on Thursday.

As of noon EST Friday, NewsNation partner The Hill reported Eli Lilly fell 4.2% percent, Amgen 4.9 percent and Novo Nordisk more than 3.1 percent. Noravak,which Reuters said only has one product, the COVID-19 vaccine, lost almost 2% Friday, Reuters wrote.

Kennedy has made false claims about vaccines and spread debunked conspiracy theories about them, such as the false idea that they can cause autism. However, he still insists that he’s not anti-vaccine, but that he wants them to be vigorously tested.

Doctors and researchers have proven that risks from disease are generally far greater than the risks from vaccines. COVID-19 vaccines have been shown to be safe and effective in protecting people from hospitalization and death in multiple studies and trials. An estimated 154 million lives have been saved in the past 50 years because of vaccines, according to the The World Health Organization.

Stephen Ubl, president of The Pharmaceutical Research and Manufacturers of America, said in a statement to The Hill Thursday that the trade association wants to “work with the Trump administration to further strengthen our innovation ecosystem and improve health care for patients.”

Speaking to NBC right after the election, Kennedy said he wouldn’t “take away anybody’s vaccines” if given a role in a second Trump administration.

“If vaccines are working for somebody, I’m not going to take them away. People ought to have choice, and that choice ought to be informed by the best information,” he told the news outlet. “So I’m going to make sure scientific safety studies and efficacy are out there, and people can make individual assessments about whether that product is going to be good for them.”

The Senate still needs to confirm Kennedy to lead the Department of Health and Human Services.

The Associated Press and Reuters contributed to this report.