The benefits of getting vaccinated far outweigh the risks. Of the more than 4 billion+ people who have been vaccinated worldwide, less than 1% have had a serious reaction or death. Side effects do not mean that you are infected with COVID-19. Side effects indicate that your immune system is strengthening its defenses.

The Centers for Disease Control (CDC), the Food & Drug Administration (FDA), in addition to the International World Health Organization (WHO), have all closely evaluated the COVID-19 vaccines and determined them to be safe and effective. In addition, the vaccines prevent hospitalization and serious illness in more than 90% of people.

Like all new drugs, the COVID-19 vaccines come with some safety concerns and side effects. Many people who’ve received the shots have experienced fever, headache and pain at the site of the injection. These side effects generally disappear quickly, 2-3 days after receiving the vaccine. This is not unusual and typically happens with any vaccine.

Risks associated with specific vaccines

Pfizer & Moderna

Several allergic reaction incidents, known as anaphylaxis, have been reported in the U.S. after vaccinations of Pfizer/BioNTech and Moderna shots. These allergic reactions happen in 0.0011% of people. In every case, the individuals have fully recovered with no lasting side effects. 2

AstraZeneca

The European Medicines Agency (EMA) said there is a risk of rare cases of thrombosis with thrombocytopenia with the AstraZeneca vaccine. These cases have appeared in less than 0.0005% of the 20 million+ people who have received the dose. 79 cases of rare blood clots with low platelets have been reported, as well as 19 deaths. However, a direct relationship between the vaccines, the thrombosis and the deaths have not been determined. 3

AstraZeneca is still being evaluated and has not yet been approved for use in the United States .

Johnson & Johnson

The CDC and FDA have recommended a pause in the use of the Johnson & Johnson’s Janssen COVID-19 vaccine in the US out of an abundance of caution, effective Tuesday, April 13. CDC will meet on Wednesday, April 14, to address this issue. Less than 0.0001% of the 6 million+ people who received the J&J dose experienced blood clotting. These symptoms appeared within 3 weeks of receiving the vaccine. 4

Vaccine Side Effects

Source: Medical News Today

It is normal for a person to experience minor side effects after receiving a vaccine, as the body builds an immunity to the virus.

According to the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO), the most frequently reported side effects of a COVID-19 vaccine include:

  • a fever

  • fatigue

  • headaches

  • body aches

  • chills

  • nausea

A person might also experience pain and swelling on their upper arm, near the injection site. This reaction might also include redness, an itchy rash, and other mild forms of irritation. People refer to this issue as COVID arm. This reaction typically disappears 2-3 days after the injection.

Allergic reactions and anaphylaxis 

Very rarely, people experience an allergic reaction to one or more of the ingredients in a vaccine. They might develop hives or another type of skin rash, swelling, and respiratory symptoms.

A severe allergic reaction is called anaphylaxis, and it involves low blood pressure, nausea, and difficulty breathing, among other symptoms.

Anaphylaxis is an extremely rare side effect of vaccination. According to the CDC, around 2–5 people per million, or fewer than 0.001% of people vaccinated in the U.S. have experienced anaphylaxis afterward.

The data suggest that there is a very low risk of anaphylaxis as a result of mRNA COVID-19 vaccines. Regardless, the CDC recommends that vaccine administrators conduct prescreening for specific allergic reactions. These vaccines are safe for people with common allergies, such as to foods, pets, environmental elements, latex, and oral medications.

The CDC also recommend that anyone who has had an allergic reaction to one dose of a vaccine not receive a second dose of the same type of vaccine.

Side effects in women

Current research suggests that side effects appear to be more often reported in women than men. A study by CDC researchers shows that 78.7% of side effects reports during the first month of U.S. vaccination involved women.

Another study observed that women represented 15 out of 16 people with anaphylaxis, or allergic reaction, after a vaccine.

These findings are in line with a 2013 study on the H1N1 vaccine during the 2009 flu pandemic, which found higher rates of hypersensitivity reactions among females of childbearing age than other groups in the study.

Reproductive hormones, such as estrogen and testosterone, may play a part in this gender difference. A lab study conducted in mice demonstrated that estrogen causes the body to generate more antibodies, leading to a higher immune response.

Side effects reporting protocol

Every vaccine facility in the United States has to report specific post-vaccination symptoms, known as adverse events, to the government’s Vaccine Adverse Event Reporting System (VAERS). Individuals can also submit reports through the VAERS portal.

The Food and Drug Administration (FDA), CDC, and other regulatory agencies are closely monitoring VAERS to scrutinize the safety of the vaccines used in the U.S.