Scientists Investigate Whether PFAS Exposure Affects COVID Vaccine Response

Scientists are asking an important question: Do “forever chemicals” in our drinking water affect how well COVID vaccines protect us? Several major research studies are investigating whether PFAS exposure might impact your immune system’s response to vaccines – and the early findings are mixed.

Here’s what researchers have discovered so far and what it means for you.

What Scientists Are Studying

Researchers have long known that PFAS chemicals can mess with your immune system. Studies in children showed that higher PFAS levels led to weaker responses to vaccines for diseases like tetanus and diphtheria. Now they’re investigating whether the same thing happens with COVID vaccines.

The big question: If nearly everyone in America has PFAS in their blood, could these chemicals be making vaccines less effective for some people?

Why this matters: If PFAS exposure reduces vaccine effectiveness, it could help explain why some people get breakthrough infections even after vaccination. It might also mean that people with high PFAS exposure need different vaccination strategies.

What the Research Shows So Far

Multiple studies have looked at PFAS and COVID vaccine response, with mixed results that scientists are still trying to understand:

Michigan Study: No Clear Effect Found

The largest study to date, conducted by the Michigan Department of Health and Human Services, followed 226 people with known PFAS exposure from contaminated drinking water. The findings were reassuring:

• Higher PFAS levels did not reduce overall antibody response to COVID vaccines
• PFAS didn’t affect how quickly antibodies formed after vaccination
• PFAS didn’t change how fast antibodies declined over time
• People with PFAS exposure still responded normally to vaccines

3M Worker Study: Small Possible Effect

A separate study of 3M workers (who had very high PFAS exposure from working at plants that made these chemicals) found small potential effects:

• 3.45% lower antibody levels for each increase in PFOS exposure
• Similar small decreases for other PFAS chemicals
• But the effects were so small that scientists couldn’t be sure they were real

Other Research: Mixed Signals

Additional studies have produced varying results:

• Some found higher PFAS linked to lower peak antibody levels after COVID infection (but not vaccination)
• Others found no significant effects on vaccine response
• Research is ongoing with different populations and exposure levels

What Makes This Research Complicated

Studying PFAS and vaccine response is tricky for several reasons:

Everyone has different PFAS levels: Some people have much higher exposure than others, making it hard to compare groups.

Multiple factors affect vaccine response: Age, health conditions, previous infections, and many other things influence how well vaccines work.

PFAS are everywhere: Since nearly everyone has these chemicals in their blood, there’s no true “unexposed” group to compare against.

Different vaccines, different responses: The immune system might respond differently to various types of vaccines.

What We Know About PFAS and Immune System

While the COVID vaccine research is still developing, scientists have stronger evidence that PFAS affect the immune system in general:

Children are most affected:

• Studies show clear connections between PFAS exposure and weaker vaccine responses in kids
• Higher PFAS levels linked to more frequent infections
• Children with high exposure more likely to be hospitalized for infectious diseases

Adults show mixed results:

• Some studies find reduced vaccine effectiveness
• Others show no clear effects
• More research needed to understand why results vary

How PFAS might interfere:

• These chemicals can suppress immune system function
• They may reduce the body’s ability to produce protective antibodies
• Effects appear to be stronger with higher exposure levels

Who Might Be Most at Risk

If PFAS do affect vaccine response, certain groups might be more vulnerable:

People with high PFAS exposure:

• Communities with contaminated drinking water
• Workers in industries that use PFAS
• People living near airports or military bases (where PFAS firefighting foam was used)
• Residents near landfills or manufacturing plants

First responders and military:

• Firefighters often have very high PFAS levels
• Military personnel exposed through firefighting foam
• These groups are already at higher risk for COVID exposure

Children and pregnant women:

• Developing immune systems may be more vulnerable
• PFAS can cross the placenta and affect babies

What This Means for You

While scientists continue their research, here’s what you should know:

Don’t skip vaccination: Even if PFAS affect vaccine response, getting vaccinated is still your best protection against COVID. The benefits far outweigh any theoretical risks.

Consider your exposure: If you live in an area with known PFAS contamination, you might want to discuss this with your doctor.

Focus on what you can control:

• Test your drinking water for PFAS
• Consider water filtration systems that remove forever chemicals
• Follow general health practices that support immune function

Stay informed: This is active research, and recommendations may change as scientists learn more.

The Bigger Picture

This research is part of a larger investigation into how PFAS affect human health. The findings have implications beyond just COVID vaccines:

Childhood vaccination programs: If PFAS reduce vaccine effectiveness in children, this could affect diseases like measles, mumps, and polio.

Public health planning: Communities with high PFAS exposure might need different vaccination strategies.

Environmental policy: These findings add to the evidence that PFAS contamination is a serious public health threat.

Future vaccine development: Understanding how environmental chemicals affect immune response could help design better vaccines.

What Researchers Are Doing Next

Scientists are expanding their investigations:

Larger studies: Researchers are following more people for longer periods to get clearer answers.

Different populations: Studies are looking at various age groups and exposure levels.

Other vaccines: Investigating whether PFAS affect response to flu vaccines, boosters, and other immunizations.

Mechanisms: Trying to understand exactly how PFAS interfere with immune system function.

Bottom Line: Research Continues, but Vaccines Still Work

The scientific evidence on PFAS and COVID vaccine response is still developing. Some studies suggest small effects, while others find no clear impact. What’s certain is that vaccines remain highly effective at preventing serious illness, even in people with PFAS exposure.

The key takeaways:

• Current research shows mixed results about PFAS affecting vaccine response
• Any effects appear to be small in most people
• Vaccines are still your best protection against COVID
• People with high PFAS exposure should discuss their individual risk with healthcare providers

What you can do now:

• Get vaccinated and stay up-to-date with boosters
• Test your water for PFAS if you’re concerned about exposure
• Consider filtration systems that remove forever chemicals
• Support policies to reduce PFAS contamination in communities

This research highlights why cleaning up PFAS contamination is so important. While we wait for definitive answers about vaccine effectiveness, reducing exposure to these forever chemicals benefits everyone’s health in multiple ways.

The good news is that scientists are taking this question seriously and working to understand how environmental chemicals affect our immune systems. This research will help protect public health now and in the future.

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Stay Informed

• Follow ongoing research – Studies continue to investigate PFAS and immune function
• Test your water – Know your PFAS exposure levels
• Talk to your doctor – Discuss individual risk factors and vaccination needs
• Support clean water policies – Advocate for PFAS cleanup in your community
• Check Your Water Quality Here

Sources: Michigan Department of Health and Human Services, Journal of Exposure Science & Environmental Epidemiology, CDC, Environmental Working Group | Last Updated: June 24, 2025