It has been over a year since the COVID-19 vaccine became available, and a subset of people with myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) are reporting adverse effects from getting vaccines and boosters from all manufacturers. There are also rare reports of people without pre-existing conditions developing Long COVID and ME/CFS symptoms after getting a COVID vaccine, and we suspect the same underlying immunological response is at play.

Vaccines save lives by preventing infections, reducing transmission and protecting immunocompromised people who may not be able to get vaccinated. However, the effects of vaccines on populations with pre-existing health conditions, a crucial consideration for any vaccine design, has been under-researched and underreported. Conversations around vaccination are polarizing and even federal agencies may underplay risk, not represent the full spectrum of vaccination responses, or evade this necessary conversation altogether.  

A complex, nuanced conversation about the impact of vaccines— especially the COVID-19 vaccines— on people with pre-existing conditions such as ME/CFS and Long COVID is important and urgent. If vaccine developers can learn why some people respond differently to vaccines we can ensure that vaccines can protect the most vulnerable. 

COVID Vaccines are Exacerbating Symptoms in a Subset of People with ME/CFS 
ME/CFS specialists and patients were concerned from the beginning whether the vaccines would exacerbate their existing symptoms.

People with ME/CFS frequently report side effects after getting vaccinated. However, because of the high risk of contracting the virus and the median severity of the disease in unvaccinated people, most doctors suggest people with ME/CFS get vaccinated for COVID-19. 

Unfortunately, the concern about whether vaccines would cause problems in a subset of people with ME/CFS has been realized. A significant number of people have reported experiencing both new symptoms and long-lasting exacerbations of their pre-existing ME/CFS symptoms after vaccines from all manufacturers, and a significant percentage of them are still not back to baseline. 

Various ME/CFS charities have done polls to try to figure out if long-term reactions are common, with one survey filled out by a total of 457 people who were part of a pre-existing registry run by Solve ME/CFS Initiative. Five months after getting their first vaccine shots, “19% of people with ME/CFS said health worsened after vaccination compared to 4% reported by controls.” However, 9% of the patients in the survey reported improvement. 

An active Facebook group with over 9,000 members exists for people with ME/CFS to discuss vaccines. A large part of the conversation is members discussing how their symptoms have worsened – or new symptoms have appeared – months after getting first and second vaccines and boosters of all manufacturers.

Nina Tomei is a former pediatrician with ME/CFS whose health has worsened after getting the Moderna vaccine in March of 2021. Nina was already experiencing profound fatigue and post-exertional malaise, but after getting two Moderna shots, she now feels like she has the flu all the time and is too unwell to leave the house. 

“I started noticing worsening of internal vibrations,” Dr. Tomei said. “My POTS (postural orthostatic tachycardia syndrome) got worse, my fatigue got worse. There was a worsening of my peripheral neuropathy pain. I had been getting IVIG (intravenous immunoglobulin) for over a year but, since the second moderna vaccine, it’s not working for the neuropathy anymore.”  

She said her daughter who has severe ME/CFS also worsened after getting two Moderna shots. 

“She used to be able to sit and eat dinner, and now she has to eat in bed and between bites, she has to lie flat,” said Dr. Tomei.  

Tom Jackman is another person with ME/CFS who has reported worsening symptoms after getting his third shot in November, 2021. 

“I had the normal flu-like symptoms for a few days, but then started to feel these crazy internal tremors, or internal vibrations,” wrote Jackman. “Anyway, fast forward a few months and the tremors/vibrations have basically spread throughout my body. I seem to have lost a lot of my dexterity so that using a keyboard and a mouse has become difficult. Even walking is difficult at times.There is also extreme weakness in my shoulders and arms, worse than anything I’ve ever experienced on the normal ME front.”

Reports of Improvement from Vaccine 
There have also been some reports in the ME/CFS community of improvement and, in some rare cases, remission from ME/CFS after getting a vaccine.  

Betsy Friedrich had developed moderate to severe ME/CFS after a bronchial infection in 2016. She also had POTS and fibromyalgia. After getting the first COVID shot, she found that she could do more without crashing. By the time she got her second shot she found she was using her wheelchair less around the house. After moving states and not crashing, she realized that she was no longer experiencing post-exertional malaise, which is the hallmark symptom of ME/CFS. It’s been a year since her vaccines and the PEM is gone. Neither Friedrich nor her doctors are able to attribute the improvement to any other changes.  

“It wasn’t until after the vaccines that the push/crash cycle of PEM stopped entirely,” said Friedrich. 

Sarah Raskin had a “magical month” of a nearly full remission from ME/CFS after getting the Pfizer shot, but her symptoms have since returned. Before getting vaccinated, she had been mostly bedbound and progressively deteriorating for several years.

Positive responses are no more surprising than negative, according to #MEAction’s Director of Scientific and Medical Outreach, Jaime Seltzer.  

“Anecdotally, people with ME/CFS have fallen into two categories of immune response: those who feel better when their immune system combats a pathogen, and those who feel worse,” Seltzer said. “In #MEAction’s solicited Request for Information to NIH in 2016, we urged researchers to study these two immune phenotypes in ME/CFS.  Given that a vaccine produces a similar immune challenge to the pathogen itself– because that is its job!– both sets of responses to vaccination are more or less what we might expect.”

In the Long COVID community, there is well-publicized early research that shows that some people with Long COVID improved after getting vaccinated against COVID-19, although it’s also important to note that in the same studies some participants report worsening.

Mark Staudinger developed mild Long COVID, and was careful about protecting himself from another COVID infection, but reports that his second Pfizer vaccination in November of 2021 has caused him to develop severe ME/CFS, leaving him bedbound with severe post-exertional malaise and severe brain fog.  

Rare Cases of Vaccines Causing ME/CFS in Healthy People 
Vaccines may also be triggering individual cases of healthy adults to develop ME/CFS. This was suggested in a retrospective study by Agmon-Levin et al which investigated the connection between hepatitis B vaccination and subsequent development of CFS and fibromyalgia in 19 patients residing throughout the US.  This can be a contentious conversation, yet this has been a repeating occurrence throughout our community’s history— and it may be happening again with the COVID-19 vaccine. 

Science Magazine has reported on ongoing research looking into the possibility that, in rare cases, some people are developing Long Covid-like symptoms after receiving COVID-19 vaccines. There are many similarities in some of the adverse events experienced by people with no known pre-existing conditions and those reported by the ME/CFS population. 

Dr Avindra Nath, the intramural clinical director of National Institute of Neurological Diseases and Stroke (NINDS), and colleagues at NIH and top institutions such as Harvard have published a preprint about various peripheral neuropathies seen in some patients after getting vaccinated.  The observational study looked at 23 patients “reporting new neuropathic symptoms beginning within 1 month after SARS-CoV-2 vaccination.” Dr Nath discussed in a 2021 Body Politic seminar how studying people with neurological side effects from the vaccines can help researchers better understand Long COVID. 

Brianne Dressen enrolled in the AstraZeneca clinical trial in November 2020. Within an hour, she began experiencing symptoms and has since developed POTS, neuropathy, short-term memory loss and additional symptoms commonly seen in Long COVID and ME/CFS. She has since launched the React19 nonprofit to offer science-based support for people experiencing adverse reactions to the vaccine. Her organization is focused on research and the daily health needs of people experiencing an adverse vaccine reaction. 

“I’m still going to believe in science,” said Dressen. “I still think science is going to be our way out of this.”  

The symptoms being reported by this community mirror the same symptoms and conditions seen in the Long COVID and ME/CFS communities, Dressen said, including autonomic dysfunction, cardiovascular inflammation, neuropathy, autoimmunity, mast cell activation syndrome, post-exertional malaise, brain fog, exercise intolerance, skin rashes, food sensitivities, tinnitus and hyperadrenergic response. 

While she calls herself pro-vaccine, she believes the people who are injured by vaccines are suffering incredible stigma, and being left behind by the CDC and NIH, and their stories exploited by anti-vaxxers. Meanwhile, the media is terrified of covering this story.  

“The majority of us chose to be part of the process, to be part of the science, to be a game player,” Dressen said. “Now, we got sick, we’re not on the team.” 

Brianne is not alone in her experience. An active Facebook group with over 4,000 members are discussing symptoms they’ve developed following the COVID-19 vaccine. 

The fact that some previously healthy people are developing ME/CFS symptoms following a vaccine is not surprising given our understanding of how ME/CFS is triggered. 

“Long COVID and ME/CFS that appears to have been initiated by vaccination highlights the nature of the disease: a genetic predisposition typically triggered by an immune challenge,” MEAction’s Seltzer said. “A vaccination represents such an immune challenge. While ME/CFS triggered by vaccination is uncommon, it is not unheard of.”

A preprint study was recently published in Research Square investigating healthy people who reported symptoms after getting the COVID-19 vaccine. The paper reported finding persistent S1 spike protein in the immune cells of 50 patients reporting post-vaccine symptoms, resembling Long COVID. It’s been an average of 14 weeks since vaccination for participants.

“If these findings are confirmed, they imply that the presence of portions of the spike protein may be causing persistent symptoms in some people after getting the COVID-19 vaccine,” concludes the preprint. “These findings could also be relevant to research into Long COVID.”

Research on Vaccine Responses does Not Include People with ME/CFS  
The National Institutes of Health is currently running a two-year observational study on how people with immune deficiencies respond to COVID-19 vaccines and boosters. The study does not happen to include people with ME/CFS, however, and focuses mostly on people with autoimmune conditions who are immunosuppressed either from medication or genetically. It’s important to note that immune function in complex chronic diseases like ME/CFS and Long COVID is seldom so cut-and-dried. In many cases, patients have some aspects of immune function that are over-active and others that are suppressed or under-active.  For example, it’s not uncommon to have elevated IgE response but sub-normal IgG levels or natural killer cell (NKC) function. 

#MEAction spoke with the NIH study’s principal investigator, Emily Ricotta, PhD, MSc, an infectious disease specialist at the National Institute of Allergy and Infectious Diseases. Dr. Ricotta says her team is writing up its first paper, and that the data is very encouraging so far in showing that very few participants in the immunosuppressed population are reporting adverse side effects compared to the healthy population. Dr. Ricotta’s study has currently enrolled 150 participants and 50 healthy controls, and is still actively enrolling. 

Dr. Ricotta said that she may be able to expand the study criteria to include people with ME/CFS if enough people are interested in participating, which involves remote blood draws. Dr. Ricotta suggested people with ME/CFS who have common variable immunodeficiency (CVID) should email her about enrolling in the study even if they’re not on immune suppressants (email [email protected]). Participants who have already had five doses of vaccines are not eligible to apply, however.    

Dr. Ricotta agreed that a study needs to be done that looks at populations who are reporting adverse reactions, like the ME/CFS community, and that she has discussed this with Dr. Avindra Nath, the intramural clinical director of National Institute of Neurological Diseases and Stroke (NINDS) who is conducting the ME/CFS intramural study, 

“This is something that needs to be pursued further, especially as more people develop Long COVID symptoms,” Dr. Ricotta said. “It’s possible that boosters could have unexpected adverse effects that people didn’t experience previously. We need to dig deeper. We’re not seeing it in our study population; it needs to have a targeted study.” 

Dr Nath discussed in a Body Politic seminar how studying people with neurological side effects from the vaccines can help researchers better understand Long COVID. Dr Nath and colleagues at NIH and top institutions such as Harvard have published a preprint about various peripheral neuropathies seen in some patients after getting vaccinated.  A preprint has not gone through peer review so the final paper that is published may be different. The observational study looked at 23 patients “reporting new neuropathic symptoms beginning within 1 month after SARS-CoV-2 vaccination.”

Medical Records Not Reporting Adverse Vaccine Effects Accurately
The symptoms that people are reporting are often not captured in electronic medical records. Relying on diagnostic codes to signal adverse events to health authorities has many limitations, as this BMJ letter explains. Neuropathies, dysautonomia, post-exertional malaise (PEM), and other symptoms and conditions often take years to be recognized and diagnosed. Exacerbation of existing symptoms may not even be reported by patients because of previous negative experiences with doctors and a lack of treatment options.

Most media outlets haven’t discussed the challenges many people with chronic illnesses have with vaccines (outside of not developing sufficient antibodies). Some outlets in New Zealand have covered ME/CFS expert Warren Tate’s push to “allow those with CFS to be exempt from the vaccine.”

It is the responsibility of institutions like the CDC and FDA to educate the general public on potential side effects of any medical intervention including interventions that those institutions are publicly advocating for, including vaccines. 

Why Research is Critical 
This problem can be improved by clear public health communication, vaccine trials that include people with ME/CFS and other chronic health conditions, and by studying adverse vaccine reactions even when it is politically unpopular to do so. 

There is a relatively recent move towards precision vaccination: adjusting the antigen in a vaccine, its dosage, the adjuvant, and other factors depending on the patient’s sex, age, immune status (immune exhaustion, immune hyperexcitability), and even where they live in the world, as each of these factors significantly affect immune response. For example, changes in adjuvants, or a substance that modulates the immune response to a vaccine, has been touted as being a successful strategy for patients who are immunocompromised. Patients with generalized immune suppression or immune exhaustion may also require more jabs before vaccination is effective.

This is why studying the effects of vaccination on people with ME/CFS and other pre-existing health conditions is urgently needed: in order to understand how to create precision vaccines for people with ME and others with similar, often post-viral chronic complex diseases like Long COVID, and to understand if and when certain vaccinations may be inappropriate for particular patients Without this research, vaccines will not be improved to support some of our the most vulnerable citizens– nor will there be clear warnings to people who may require alternatives to certain vaccines. Manufacturers should be required to study their vaccines in people with a range of pre-existing health issues, especially when there are mandates in place.

Understanding these issues presents an opportunity for researchers, clinicians, public health agencies, pharmaceutical companies, and the community to come together to improve vaccines for the vulnerable.  We must ensure that everyone whose health has been impacted by both COVID-19 and vaccines can be supported, with the ultimate goal that issues around vaccination be better researched, better funded, and ultimately, more fully understood.