Should people with ME/CFS, FM and Environmental Sensitivities get the COVID vaccine?

Mar 19, 2021

With very few exceptions - YES.


August 22, 2021: Updated COVID information: The effectiveness of COVID-19 vaccines on the delta variant.


How are people with ME/CFS, FM and ES responding to the COVID vaccines?

Since publishing my blog on the COVID vaccine in April 2021, I continue to receive questions about whether my opinion that everyone will benefit from vaccination has changed or not. I am grateful to the many people who have sent me information about their responses to the vaccine and in my ongoing therapy groups, it is a frequent topic of discussion.

Many people with ME/CFS and environmental sensitivities have had strong immune reactions to the vaccine causing fatigue lasting for days or even weeks. Fibromyalgia is not associated with immune activation. Therefore, people with primary FM are not at the same risk of a strong reaction from vaccines. A couple of patients have reported temporary neurological symptoms post-vaccination. No one has had a permanent or serious side effect. Conversely, several of my patients have contracted COVID in the past year and have been unwell for months. Fortunately, none have been hospitalized or died, though a handful of patients had elderly relatives who passed away due to COVID prior to vaccines becoming available. 

Are COVID vaccines effective against the delta variant?

I attended a talk this week by Dr. Deena Hinshaw, the Chief Medical Officer for Alberta. She reported on the effectiveness of vaccination against the delta variant which now comprises almost all cases in Alberta. The Alberta data shows that since January 2021,

  • 0.1% of people who are double vaccinated have contracted COVID vs. 5.5% of those unvaccinated.
  • 94% of all confirmed cases of COVID have occurred in people who are unvaccinated or partially vaccinated.
  • 91% of hospitalizations for COVID occurred in this group.
  • 86% of deaths due to COVID occurred in this group. 

The conclusion from this real-life data is that even against the delta variant the mRNA vaccines (Pfizer and Moderna) are extremely effective. The Astra Zeneca vaccine is slightly less effective but still much better than being unvaccinated. 

Dr. Lenore Saxinger (Infectious Disease, University of Alberta) stated in a recent University of Calgary podcast that being double vaccinated transforms the risk of serious disease or death from COVID to one of getting a bad cold. It is not yet known how many people, who acquire COVID after being double vaccinated will go on to experience long COVID despite having a mild illness.

How many people in the United States who are fully vaccinated get COVID?

The Centers for Disease Control in the United States reports very similar data. 

  • Over 166 million people have been fully vaccinated in the United States. 
  • Of these 8,054 have contracted COVID resulting in hospitalization or death. 
  • This equals a very low rate of hospitalization or death from COVID among the fully vaccinated of 0.0004%.

The CDC recommends that people who are double vaccinated can safely go about their daily activities but continue to wear a mask when in indoor spaces with many people whose vaccination status is unknown. 

With the original COVID and earlier variants, people who were double vaccinated transmitted as few as 10% of the number of vaccine particles as those who were unvaccinated. With the delta variant, this may be different. Studies measuring the number of particles in nasal swabs of people positive for the delta variant show that those vaccinated and unvaccinated have similar numbers. This is indirect evidence and doesn’t prove transmission. In early July there was an outbreak of COVID among travellers to Provincetown, Cape Cod. Of 60,000 people in the area that week, 965 people contracted COVID and of these 75% were fully vaccinated. The good news is that only 7 people were hospitalized and none died. This is more real-world evidence that being double vaccinated will protect you. But it may not protect those around you. More research is needed. 

Will I Need a Booster Shot for Covid-19?

The immunity from contracting COVID and from the vaccines decreases by about 6% per month. For this reason, although the current vaccines are very effective, we will need regular boosters to maintain good immunity.

The CDC recently announced they will be recommending a third vaccine booster for those who are over 8 months since their second vaccine. As with the first two doses, the elderly and immune-compromised will be at the front of the line to get a booster. In a recent educational podcast at the U of Calgary, Dr. Saxsinger points out that those who had a long gap between the first and second vaccines may have better and longer immunity than those who got both injections 3 - 4 weeks apart. She recommends waiting if possible for a delta or other future variant-specific booster before going for a third injection. The Canadian authorities have not yet released a plan for third or booster vaccines in Canada. 

What Was my Experience with the COVID Vaccine? - A Medical Specialist’s Experience. 

After my first dose of mRNA vaccine I was very fatigued and sleepy for one day and then bounced back. I had decreased energy and general malaise for about a month after my second vaccine dose. It is always hard to attribute causality because lives are not controlled - many things happen at once. Nevertheless, I have resumed my full activities including writing this blog, so I suspect the vaccine played a role. 

I am glad to have had the vaccine. Knowing the data of its effectiveness, I have felt safe to be around more people (especially those who are also double vaccinated). I have had a couple of outings in public places and wore a mask to lower my risk. I am anticipating the ability to travel again as soon as borders open.

Here is the original blog post from March 2021

  • The risk of infection with COVID-19 in Canada is 2.4%, albeit less for people who rarely go out and have few close contacts. Of those who contracted the disease in Canada, 2.5% have died with the highest risk being among the frail elderly.
  • The risk of long-term ME/CFS-like effects from COVID-19 infection is significant. In a preprint study (not yet peer-reviewed) released this month 27% of those infected reported persistent symptoms after 60 days. Women were more likely than men to become long-haulers. A study by volunteer researchers from the Body Politic website report that the symptoms of long haul COVID include all those experienced by people with ME/CFS (fatigue, post-exertional malaise and cognitive dysfunction are the top three symptoms reported). In addition, many people have COVID-specific symptoms such as cough, shortness of breath and difficulty talking.
  • In a research trial of over 75,000 people, among those who were vaccinated with the 4 approved vaccines (plus Novavax which is coming soon), there have been no deaths from COVID and only a few hospitalizations. This means that all 5 vaccines are very effective in preventing severe outcomes – the ones we are most scared of. And equally important, there are no deaths proven to be a result of any of these 5 vaccines.

The benefit/risk ratio is decidedly in favor of being vaccinated.

The rationale for vaccination is even stronger if you want to be out in society, around people who are or want to be in contact with elderly friends or relatives.

What are the very few exceptions to the recommendation for universal vaccination?

If you have had an anaphylactic reaction to any of the ingredients of a vaccine (see lists below), you should not take it without consulting your physician. If you are on a strong immune suppressant such as some cancer chemotherapies or rituximab you should discuss the timing of the vaccine with your prescribing doctor to ensure it is given at a time when you are able to mount an immune response. Otherwise, it won’t help you.

Pfizer and Moderna (mRNA in lipid nanoparticles) Information

The Pfizer vaccine is the most tested because of the careful study of the entire population of Israel. It is assumed the Moderna vaccine will have similar results but that has yet to be proven.

  • 95% effective for all severities of symptomatic illness (mild, moderate and severe).
  • 86% against the UK variant and effectiveness.
  • Unknown against the other variants

AstraZeneca (Monkey adenovirus carrying DNA of spike protein)

  • 63% effective in the clinical trial for all severities of symptomatic illness.
  • Appears to be gaining effectiveness over time up to 12 weeks post the first injection.
  • Unknown against the variants

Johnson and Johnson (Human inactivated adenovirus carrying DNA of spike protein)

  • 66% against moderate and severe illness.
  • Effective against South Africa variant.
  • Unknown against other variants

Novavax (lab-grown spike proteins in lipid nanoparticles with adjuvant)

  • Submitted for approval Jan 29, 2021
  • Will be produced in Canada (eventually)
  • 95% effective in the clinical trial
  • 86% effective against UK variant
  • 49% effective against South Africa variant.
  • Causes very strong immune responses. 

COVID-19 vaccine ingredients: What is in the COVID-19 vaccines? 

You will see from the list of ingredients below that the two mRNA vaccines have many more difficult to pronounce chemical ingredients. The ingredients thought to be causing allergic reactions are PEG-2000 and polysorbate 80 – found in all the approved vaccines so far.

Pfizer Vaccine Ingredients

ALC-0315 = ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate) ·ALC-0159 = 2-[(  glycol)-2000]-N,N-ditetradecylacetamide ·1,2-distearoyl-sn-glycero-3-phosphocholine·cholesterol·dibasic sodium phosphate dihydrate·monobasic potassium phosphate·potassium chloride·sodium chloride·sucrose·water for injection

Moderna COVID-19 Vaccine Ingredients

1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) ·Acetic acid·Cholesterol·Lipid SM-102·PEG2000 DMG1,2-dimyristoyl-rac-glycerol,methoxy-polyethyleneglycol·Sodium acetatetrihydrate·Sucrose·Trometamol ·Trometamol hydrochloride·Water for injection

AstraZeneca Vaccine Ingredients

Disodium edetate dihydrate (EDTA) ·Ethanol·L-Histidine·L-Histidine hydrochloride monohydrate·Magnesium chloride hexahydrate·Polysorbate 80·Sodium chloride·Sucrose·Water for injection

Janssen (Johnson and Johnson) COVID-19 Vaccine Ingredients

2-hydroxypropyl-β-cyclodextrin (HBCD)·citric acid monohydrate·ethanol·hydrochloric acid·polysorbate-80·sodium chloride·sodium hydroxide·trisodium citrate dehydrate·water for injection

Novavax COVID-19 Vaccine Ingredients

Polysorbate 80·matrix M1 adjuvant

What are some common side effects of the covid 19 vaccines? 

Health Canada keeps a log of all reported vaccine side effects. At least half of the people will have mild reactions such as soreness at the injection site and fatigue or malaise, especially after the second injection. Few of these people will report these expected reactions to Health Canada. Most severe reactions requiring medical care will be reported so the data on serious reactions is likely accurate.


As of March 5, 2021, a total of 2,255,174 vaccine doses have been administered in Canada. Any adverse events (side effects) have been reported by 1,923 people. That’s about 1/1000 vaccinated individuals.

  • Most adverse events are mild and include soreness at the site of injection, fatigue, headache or low-grade fever.
  • Of the 1,923 individual reports, 214 were considered serious. That’s about 93 per million.
  • There have been 50 cases of anaphylaxis, none fatal. This rate of anaphylaxis is 10X higher rate of anaphylaxis than the flu vaccines. See the study here.
  • There are assorted rare reports of neurological symptoms such as facial paralysis and other types of paralysis in vaccine recipients. There are also reports of serious adverse events in the people who didn’t get the vaccine. So far it is no signal that the vaccines caused these serious side effects.

Are people with ME/CFS more likely to have an adverse reaction from the COVID vaccines?

ME/CFS is a disease that affects the immune system. As I mention in my blog post about the flu vaccine the immune status of people with ME/CFS is variable. Many people, especially early in the illness course have overactive immune systems. These individuals are likely to have a strong flu-like reaction to any vaccine. ME/CFS is often associated with impaired immune function especially of NK cells and T cells. These are not the primary targets of vaccines but nevertheless, these individuals may have a less effective immune response to vaccines. Since the immune testing to see which of these groups you may fall into is not available, your best predictor of response to the COVID vaccine may be a response to previous vaccines you have taken like the flu vaccine. ME expert Dr. Nancy Klimas warns people with ME/CFS to expect to be harder hit by the vaccine than others due to immune activation She has recommendations of supplements that may ease the reaction severity especially for people with MCAS.

Cort Johnson’s Health Rising blog survey has been collecting information about the vaccine experience of people with ME/CFS and FM. When you get vaccinated  please consider adding your experience to the growing database 

Here is what Cort's followers report. Most people tolerate the first Pfizer/Moderna vaccination shots easily with about 2/3rds reporting mild or non-existent symptoms. Many more people reported experiencing more severe symptoms with the AstraZeneca vaccine (47% reported moderate symptoms and 31% reported severe symptoms). Seventy-plus percent of people report being fully recovered from the first injection of these three vaccines within a week.

The second Pfizer/Moderna vaccination shot is producing more severe symptoms though over 70% report full recovery within a week.  Too few people reported on the side effects from the second AstraZeneca shot to calculate percentages.  Four to nine percent of people taking the second dose of the Pfizer or Moderna vaccine reported having symptoms a month later.

The same survey reports that people with ME/CFS/FM report that recovery from actually having the virus is more difficult. Approximately forty percent of ME/CFS/FM patients who reported they thought they’d come down with the coronavirus reported not being back to baseline three months later.

So although there are some people experiencing long-term side effects possibly related to the vaccine, far more experience long-term effects from COVID-19.

Are people with MCS more likely to have an adverse reaction from the COVID vaccines?

Except in the case of people with Mast Cell Activation Syndrome (MCAS), MCS is not a disorder of immune activation. Therefore, people with MCS are not in danger of serious or life-threatening reactions to vaccines. They may react more than the average person to the ingredients of the vaccine. These ingredients are found in tiny amounts and in most cases, the reaction will pass quickly. It is a small price to pay for the health benefits of the vaccine. The American College of Asthma, Allergy and Immunology states that people with common allergies to medications, foods, inhalants, insects and latex are no more likely than the general public to have an allergic reaction to the mRNA COVID-19 vaccines. 

Are people with ME/CFS immunocompromised?

Many people with ME/CFS believe they are immune-compromised, especially those who have a long history of catching more infections than others and getting more severely ill than others when they do catch something. While this may be true for some, the immune functions that are often impacted in people with ME/CFS are not measured in the Canadian health care system. For this reason, it is unlikely that ME/CFS will be considered a health condition that puts people at higher risk leading to early immunization. The Alberta list of compromising medical conditions.

So, all this being said, you may be wondering what am I planning to do?

Given the possibility of serious side effects from some batches of the Astra Zeneca vaccine (currently being offered to my age group) and the good track record of the mRNA vaccines, I am staying home and waiting until an mRNA vaccine is available to me.

Good luck with your vaccination experience.

Author: Eleanor (Ellie) Stein MD FRCP(C)

I am a psychiatrist with a small private practice in Calgary and am an assistant clinical professor in the faculty of medicine at the University of Calgary. Since 2000, I have worked with over 1000 patients, all with ME/CFS, FM and ES. My passion for this field comes from my own struggle with these diseases, my desire to improve my health and then pass on what I learn. My goal is for every patient in Canada to have access to respectful, effective health care within the publicly funded system.  


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