Why More Women than Men Have Side Effects from Coronavirus Vaccines

After this incredibly difficult year, when the coronavirus pandemic raged around the globe, those who receive any dose of the nearly-miraculous coronavirus vaccines are undoubtedly grateful for them. But side effects — some completely unexpected — are cropping up, especially in women who have received the vaccines, and this is especially pronounced after the second dose.

Some of the symptoms include the expected soreness at the injection site, muscle pain, and fatigue — all symptoms that occur normally after annual flu injections.

A CDC study published in late February showed that the most commonly-reported symptoms at that time were headache, with 22.4% of vaccinated people reporting this, followed by fatigue, at 16.5%, and dizziness, which was experienced by 16.5% of the respondents.

But some of the more unusual symptoms have not routinely been reported before in those receiving vaccinations — including brain fog, now popularly called “Vax fog,” strange dreams, and ongoing dizziness, along with facial (“Bell’s”) palsy.

Coronavirus vaccine experience vastly different for males vs. females

A recent story published in Health magazine brought to light some eye-popping numbers regarding vaccine side effects in males vs. females. As the author states, as with so many other side effects from so many drugs, the comparison between the sexes is not even close.

The US Centers for Disease Control and Prevention (CDC) amassed enormous amounts of data from the first month of coronavirus vaccinations in late February, and found that there was indeed a clear sex divide in reported side effects.

All those who were given the first 13.7 million doses of the vaccine — along with all those who are being vaccinated right now — were encouraged to report any side effects they experienced through “V-Safe,” the CDC’s after-vaccine health checking app.

Of the 6,994 people who took the time to report side effects after receiving the vaccine, 79.1% were female. This is especially noteworthy considering that just 61.2% of those who were vaccinated at that time were women.

All anaphylaxis victims in early coronavirus vaccine study were female

A different study from the CDC that was published in the Journal of the American Medical Association (JAMA) in January, showed that all the nineteen individuals who experienced the severe, potentially life-threatening allergic reaction of anaphylaxis after receiving the Moderna vaccine were female.

And remarkably, so were 44 of the total of 47 individuals who experienced the same reaction after receiving the Pfizer-BioNTech coronavirus vaccine.

Reports from vaccine recipients abound, relating symptoms such as brain fog and anxiety, after women received the coronavirus vaccines, especially after the second dose.

A recent New York Times article related the story of Shelly Kendeffy, a 44-year-old medical technician who lives in State College, Pennsylvania. After she says she and her colleagues — including eight men and seven women — received their second dose of the Moderna vaccine, they experienced drastically different reactions to it.

Six of the women she works with said that they experienced body aches, chills, and fatigue; one had even vomited as a result of the nausea. Only four of her male coworkers experienced very mild symptoms — and four reported that they had experienced no symptoms whatsoever.

Kendeffy herself reported experiencing “flu-like” symptoms from the dose, but began to feel better within 24 hours. She told reporters that while she “wouldn’t change a thing,” she added that she “didn’t know what to expect” before receiving the shot.

Why do more women than men report vaccine side effects?

“I don’t think there’s enough information to be able to draw any strong conclusions about why this may be occurring more in females than males,” says infectious disease expert Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, in the Health article.

It is entirely possible that women are simply more likely than men to report their symptoms, he says.

This may well be true, but issues with females being given too much medication relative to their body size is a well-known, ongoing problem in the medical field.

A 2019 study published in the Journal of Allergy and Clinical Immunology analyzing post-vaccine anaphylaxis from 1990 and 2016 showed that women made up 80% of all anaphylactic reactions to vaccines in adults.

The link, Dr. Adalja, admits, is “something that needs to be studied in more detail to be able to be fully unraveled.”

In addition, says Dr. William Schaffner, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, “it seems to be because their immune system is more reactive.”

Hormones, metabolism play a role in vaccine reactions

Women do suffer from more autoimmune diseases than men do; while the medical professor says the exact reason for this is unclear, hormonal differences between the genders may be the main factor.

Schaffner explains that estrogen somehow “jazzes up” the immune system, while testosterone seems to dampen it a little.

“There is a real difference between immune reactions between men and women,” the physician admits, adding “we in the medical community haven’t studied that as thoroughly as we ought to.”

Males and females simply metabolize drugs differently, explains Jennifer Wider, MD. “Clinical trials often do not take into account this difference and the vaccine dose may be on the higher side for female recipients,” she notes.

Adding to the mix is the fact that antibody responses to the coronavirus vaccines may also be slightly higher in females than males, she states. Research shows that the difference here is pronounced even more as ages increase. This she posits, may be the reasons why the side effects “may be more robust.”

Some of the usual — and unusual — side effects reported after vaccination

According to ongoing CDC studies, among those who did report side effects, approximately 17% said they felt dizzy following their vaccination. A CDC report using data available in February noted that dizziness was the third most common side effect people experienced after getting either the Moderna or Pfizer vaccine. At that time the Johnson & Johnson vaccine was not yet available.

“Vax fog”

A term that is circulating in social media, “vax fog,” refers to the brain fog that occurs in some people who have received a coronavirus vaccine. As with these more unusual side effects, there is no official data yet on this often-reported occurrence, although some researchers say it is related to headaches, another, much more common side effect.

Strange dreams

The odd dreams that many people report to have experienced after getting their  were not not reported in clinical trials for the vaccines, according to Dr. William A. Petri, the chief of the division infectious diseases a the University of Virginia in Charlottesville. “The CDC is accumulating self-reported data from the millions of people receiving the vaccine. This will help us gather more information on the rare side effects,” he says.

Bell’s palsy

Bell’s palsy, the weakness and partial paralysis of the face, usually affecting only one side of the face, also occurs as a reaction to the annual flu vaccine as well. A study from 2013 published in the journal Vaccine revealed findings made after the widespread administration of the 2009 H1N1 vaccine.

The study found that women between the ages of 20 and 59 reported much higher rates of allergic reactions than men, although more men than women in that age cohort received that vaccine.

“Covid arm”

This side effect, reported anecdotally by many who have received the different coronavirus inoculations, is different than the usual, mild upper arm tenderness post-injection that nearly everyone feels after any vaccination.

“(COVID arm) happens about five to seven days after the vaccine when you develop a red, itchy arm,” according to Dr. Kathleen Mullane, the director of infectious disease control trials at the University of Chicago.

The red lesion that typically forms at the injection site on the upper arm can be anywhere from one inches to 5fully five inches square, she says. “We’re not sure what this reaction is, but we think it may be that the vaccine moved outside the muscle and into the soft tissue,” Mullane explains. It’s not considered common among all those who receive coronavirus inoculations  and only occurs in a small percentage of people, she states.

If you do develop this symptom, experts say you can take an antihistamine or apply topical cortisone to quell itching. You can also put a cool, wet washcloth on the area. Once “Covid arm” goes away and it’s time for your second dose, the CDC advises to consider switching arms.

To become vaccinated as soon as possible is of utmost importance

However, do not panic even if you experience one of the above symptoms, because “This means the vaccine is working,” says Jamie Alan, PhD, an associate professor of pharmacology at Michigan State University, in the Health article.

Greek health authorities announced on Monday that the benefits of the AstraZeneca vaccine against Covid-19 far outweigh the risks associated with thrombosis.

The head of the National Vaccination Committee, Maria Theodoridou, said that the recent death of a vaccinated person may be Greece’s first incident of a rare syndrome that has been observed after the administration of an AstraZeneca vaccine.

She noted however, that an official correlation between the two is still pending.

Theodoridou said that in the EU, only 44 cases of the sudden onset of thrombosis with thrombocytopenia (a low platelet count) have been observed in a total of 9.2 million registered doses of AstraZeneca vaccines administered.

The vast majority of physicians and health organizations worldwide stress the utmost importance of receiving the coronavirus vaccine as soon as it becomes available to you. This is the only way to help stop the spread of the coronavirus and limit the further spread of its variants, which are now spreading much faster than the original coronavirus strain.