Learn about the main adverse effects of the covid-19 vaccine

Posted on 7/2/2021 5:36 PM / Updated 7/2/2021 5:37 PM37

Adverse reactions to covid-19 vaccines have become a common question among people seeking immunization, but Experts ensure the efficiency of the applications And remember that the symptoms of the disease can be worse than the possible effects caused by the vaccination.

The vaccine induces an immune response that can generate some discomfort, depending on the person. But this is to be expected. This could be an indication that your immune system is primed to protect you.

Negative feedback

According to Eduardo Silvera, an immunologist and professor at the University of São Paulo’s School of Pharmaceutical Sciences (USP), adverse reactions to vaccines are common not only against COVID-19, but also for any other disease. “The occurrence is due to a combination of factors. Among the factors already associated with these reactions in the scientific literature, we have: genetic factors (hormones, gender, race, BMI, etc.), immunity to the vaccine, the method of administration of the vaccine, Silvera explains: and inadequate handling of the vaccine, and problems with manufacturing the immunizing agent, among other things.”

The chances of adverse effects are greater for the second dose than for the first dose, says the professor, and an inflammatory process of greater magnitude at the injection site is to be expected compared to the first dose. “It is the natural response of the immune system when it is stimulated over and over by the same antigen to gain greater protective ability. In addition, some scientific articles also suggest that this could have a direct relationship to how a person’s first dose was the vaccination experience,” he explains.

In addition, Eduardo Silvera stated that there is not necessarily a relationship between adverse effects and vaccine efficacy. “What has been reported by the scientific community is that the higher the immune capacity of the vaccine, the greater the chances of adverse reactions. However, this can vary widely depending on the type of vaccine formulations used.”

It highlights the yellow fever virus vaccine, which consists of live attenuated viral particles and presents itself as one of the most efficient vaccines in the world, with about 95% of those vaccinated being protected after its application. “Forms of this type tend to be highly immunogenic. Despite this, the incidence of adverse reactions from them is minimal and when they do occur, they are often mild,” comments the immunologist.

Regarding contraindications for those who will be taking the COVID-19 immunizing agent, Silvera notes that the US Centers for Disease Control and Prevention stresses that if an individual is using antibiotics, they should not take any vaccine. “Once the infection has cleared up and antibiotic treatment has been completed, a person can seek a health facility to be vaccinated.”

But there is no interaction between antibiotics and vaccines according to the US National Foundation for Infectious Diseases (NFID). Thus, antibiotics can be used after vaccination. Likewise, other medications such as antipyretics can also be used to relieve pain in the body and control vaccine-induced fever,” says Eduardo Silvera.

The reason for the reactions

According to Alberto Chapoo, Director of the Department of Infectious Diseases at Clementino Fraga Felho Hospital and Vice President of the Brazilian Society of Infectology, reactions occur by stimulating the immune system by an attacking agent, in this case the components of the vaccine. “This stimulant triggers an immune system reaction that can cause fever and other adverse reactions of short duration and severity,” he comments.

The infection specialist still remembers: “The reaction is individual and has nothing to do with the response to the vaccine. The fact that a person did not have a reaction to the vaccine does not mean that there was no response from the immune system.”

Symptoms of possible negative effects

Roberto Bolilla, professor at the Ribeirão Preto School of Medicine (FMRP) at the University of São Paulo, stresses that vaccines are safe and that their effects are common. “What we have seen is that when you have an adverse effect, it can be mild or more severe. Milder effects are more common and more rare. Moderate reactions are fever and pain at the application site 24 or 48 hours after vaccination,” he comments. Not everyone feels these inconveniences after being vaccinated against COVID-19.

Regardless of the laboratory that produced the vaccine, adverse effects of immunization are mild and moderate, and more severe cases are very rare. “We’ve noticed that it’s more common with Astrazeneca vaccines and it appears to be with Janssen vaccines as well, since they have the same structural platform as the vaccine,” Bollela considers. Regarding Coronavac dosing, few reports have been noted. Pfizer’s Immunization Device has been shown to be completely safe with few adverse events for the most serious events.

The “noticeable” effect is an increased risk of venous thrombosis, which remains very rare. Much rarer than, for example, if contraceptives are used.” In addition, there are “other risk factors such as obesity or a previous clotting problem.” However, Roberto Bolilla stresses: “The benefit of the vaccine greatly outweighs the risks.” “In some populations, because of this additional risk, some vaccines have been suspended, for example the Astrazeneca vaccine that has been suspended in pregnant women because there are others that have a lower risk,” he said.

Reactions can be very common (occurring in 10% of patients), common (occurring between 1% and 10% of patients) and uncommon (occurring between 0.1% and 1% of patients).

Pfizer

Very common reactions: Pain, swelling at the injection site, fatigue, headache, diarrhoea, muscle aches, joint pains, chills and fever.
Common reactions: Redness at the injection site, nausea and vomiting.
unusual reactionsHypersensitivity reactions such as rash (skin damage), itching, hives (severe skin sensitivity and itching), angioedema (swelling of the deeper parts of the skin or mucous membrane), feeling unwell, pain in the extremities (arms) and insomnia.

Coronavac

Very common reactions: Pain at the injection site.
Common reactionsItching, redness, swelling, stiffness at the injection site, nausea, diarrhea, headache, fatigue, muscle pain, cough, joint pain, itching, runny nose, pain when swallowing, and nasal congestion.
unusual reactions: Hematoma at the application site, vomiting, chills, decreased appetite, allergic reaction, dizziness, hematoma, hypothermia, discomfort in the extremities and muscle weakness.

AstraZeneca

Very common reactionssensitivity, pain, feeling hot, redness, itching, swelling or bruising (purple spots) where the injection was given, general feeling unwell, feeling tired (tired), chills or feeling feverish, headache, nausea (nausea), joint pain and pain in the muscle;
Common reactionsSwelling at the injection site, fever, feeling sick (vomiting), cold-like symptoms such as high temperature, sore throat, runny nose, cough, chills.
unusual reactionsDizzy feeling. lack of appetite; Abdominal pain, excessive sweating and itching or rash.

Bolilla recalls that in the case of Covid, it is very likely that other vaccines will be needed in the future to boost immunization. “If a person has a more serious adverse effect, they need to communicate because this can help direct future doses to another type of vaccine so that this does not happen again,” recommends the professor.

* Trainee under the supervision of Roberto Fonseca