PFE, MRK, SNY, MRNA In Focus As Trump Reportedly Eyes Executive Order On Vaccines And Autism

• Decades of rigorous scientific research have consistently found no causal connection between childhood vaccines and autism.
• However, Robert F. Kennedy Jr., now Health and Human Services secretary, has been a central figure in the modern anti-vaccine movement for two decades.
• In May, the administration ordered the Centers for Disease Control and Prevention and its vaccine advisory panel to review U.S. childhood vaccine recommendations and consider aligning them with other developed countries that use fewer routine shots.

The Donald Trump administration is reportedly actively considering an executive order on vaccines and autism, with a possible move as early as the week ahead.  

The order’s contents remain unclear, and timing could shift, Bloomberg reported, citing people familiar with the matter. According to the news platform’s sources, the options under discussion by officials include research efforts that cover both prospective studies and reviews of historical data.

Any order casting doubt on vaccines or further curtailing recommendations could pressure shares of major manufacturers reliant on childhood and routine immunization revenue. Key names include Pfizer (PFE), Moderna (MRNA), BioNTech (BNTX), GSK (GSK), Sanofi (SNY), and Merck (MRK).

While PFE, MRK, and SNY shares traded marginally lower after-hours at the time of writing, MRNA edged up 1.5%, likely due to the recent approval of its flu vaccine on Wednesday.

The War Against Vaccines

Decades of rigorous scientific research have consistently found no causal connection between childhood vaccines and autism.

Robert F. Kennedy Jr., who serves as Health and Human Services secretary, has long been a leading voice in the modern anti-vaccine movement through his earlier leadership of Children’s Health Defense. In the current administration, he has overhauled a federal autism advisory panel by appointing members affiliated with organizations that advance unproven claims of vaccine-autism links, ordered research aimed at exploring such connections, and backed efforts to scale back the recommended childhood immunization schedule.  

President Donald Trump has voiced skepticism about vaccines for more than a decade, including assertions dating to the 2016 campaign and earlier that childhood immunizations contribute to autism. He has also repeated unsupported associations involving vaccines, acetaminophen use during pregnancy, and climbing autism diagnosis rates, while advising parents to space or postpone certain shots—even as he has stated that he remains in favor of vaccines overall.  

In May 2026, the administration issued an executive order directing the Centers for Disease Control and Prevention and its advisory committee to review an HHS assessment and realign the U.S. childhood vaccine schedule with practices in peer-developed countries that recommend fewer routine shots; earlier related moves faced court challenges.

How Did Retail Traders React?

On Stocktwits, retail sentiment around iShares U.S. Pharmaceuticals ETF, which holds major multinational vaccine producers alongside general drug manufacturers, rose from ‘bearish’ to ‘bullish’ over the past 24 hours, while retail chatter stayed at ‘low’ levels.

IHE has gained 21% year-to-date. 

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