COVID Vaccine: Why Do Women Get More Side Effects Than Men After Vaccination?

India began its COVID-19 vaccination programme on 16 January, starting with healthcare workers in the first phase. According to updated information, 74 crore doses have been administered, with 12 per cent of the population is fully vaccinated [1].

The COVID-19 vaccines are no different from the other vaccines; one does not need to prepare themselves for any side effects. However, there have been reports of people experiencing mild to severe side effects, with severe ones being only a very small section [2].

The side effects, such as headache, body pain, diarrhoea, hair loss etc., caused by the COVID-19 vaccine are signs that the body's immune system is responding to the vaccine, and that is okay - it is a sign that your immune system is healthy and well-functioning [3].

In a recent report, there were mentions that women are more prone to COVID vaccine side effects than men.

Are Women Prone To COVID Vaccine Side Effects Than Men?

According to the Centre for Disease Control and Prevention, while the side effects of the COVID-19 vaccine reported were not severe, women were reported to have experienced more vaccine side effects than men [4].

The data published in the Morbidity and Mortality Weekly Report stated that out of the total number of vaccinations administered, 79 per cent of side effects were reported by women, although about 60 per cent of the doses were administered to women. That is, 19 women who received the Moderna shot reported having an adverse reaction, while 44 per cent of women who complained of anaphylactic reactions were given the Pfizer shots [5].

According to the study, the following reasons were asserted to be responsible for women reporting to have more side effects than men:

• The female immune response is distinct, in many ways, from the male immune response.
• It has been shown that the female body tends to produce more (twice as many) infection-fighting antibodies in response to the vaccines for influenza, M.M.R., yellow fever, rabies, and hepatitis A and B.
• The high levels of oestrogen in the female body resulting in a stronger immune system, thereby causing more side effects. Progesterone and testosterone too can influence the vaccine reactions. When exposed to the oestrogen, the immune cells tend to produce more antibodies in response to the vaccine.
• Hormonal fluctuations in the female body are touted as another reason [6].
• Another study pointed out that the reason behind the reports of side effects could be behavioural factors - that is, women may be more likely than men to report side effects even when their symptoms are the same [7].
• Several studies have shown that women absorb and metabolise drugs differently than men do.

Furthermore, a 2013 study had shown that four times as many women (between the ages of 20 and 59) reported allergic reactions after receiving the 2009 pandemic flu vaccine, which in turn corroborates with the recent findings that women can experience severe vaccine side effects that men [8]. Another study found that women accounted for 80 per cent of all adult anaphylactic reactions to vaccines [9].

A medical officer in the C.D.C.'s Immunization Safety Office said, "in general, women have reactions to a variety of vaccines. And this includes influenza vaccines given to adults, as well as some given in infancy, such as the hepatitis B and measles, mumps and rubella (M.M.R.) vaccines."

Are The COVID Vaccine Side Effects Concerning?

In a single word, NO. The vaccine side effects are mild and short-lived, and more importantly, these side effects are a sign that the vaccine is working and the immune system is well-functioning. Due to the difference in the genetic structuring of the male and the female body, the way the vaccine works will be different. Studies have shown that the female body possesses a stronger response from immune fighters called T cells, and it is largely observed in younger adults [10].

While headache, pain in the injected region, fever, fatigue and nausea are the common side-effects after COVID-19 vaccination, some women have reported experiencing changes in their menstrual cycle after getting vaccinated. The common changes described in the reports include heavy periods, bleeding between periods and vaginal bleeding after menopause [11].

There is no actual data or evidence to connect COVID-19 vaccines to your menstrual cycle. While several women have reported changes in their menstrual cycle, experts added that all these could be temporary side effects. Women should go ahead and get vaccinated without any worry - and the same goes for all the side effects reported.

In addition, the COVID-19 vaccines are safe for pregnant women, breastfeeding moms and women trying to get pregnant [12]. A vaccine may have side effects, which are normally mild - like any other medicine. In most cases, the woman may get a mild fever, pain at the injection site or feel unwell for 1-3 days.

On A Final Note...

Get immediate medical attention if you experience severe vaccine side effects such as blood clots, seizures, intense headaches, and allergic reactions.