What are they, when do they appear and how long do they last?

  • Fever, malaise and muscle pain stand out as the most common adverse effects of covid-19 vaccines such as AstraZeneca, Pfizer or Janssen

Vaccines work like a drill. His goal, in fact, is none other than train the human body so that, in case of need, you know how to defend against attack of a certain pathogen. Covid-19 vaccines, for example, introduce fragments of genetic material from the SARS-CoV-2 coronavirus to generate a specific immune response. Thus, if a person comes into contact with the virus, his body already has antibodies with which to defend oneself.

All approved vaccines against covid-19 they are safe and effective, as certified by clinical trials and the review of regulatory bodies such as the European Medicines Agency (EMA). The Adverse effects found after punctures from Pfizer, Moderna, AstraZeneca and Janssen are just one proof that immunizations are indeed working, as they show that the drill against the coronavirus has been launched.

It is normal for a vaccine to produce a fever, malaise and some fatigue. These kinds of mild reactions, in fact, fall within the foreseeable after any type of vaccination. But since the covid-19 formulas have been developed in record time and under continuous public scrutiny, these adverse effects are often perceived with a little more concern. The good news is that the deployment of these vaccines was accompanied by a pharmacovigilance system that records the adverse events detected after vaccination to guarantee the safety of the formulas at all times.

Most common adverse effects

After three months of the vaccination campaign against covid-19 and more than three million doses distributed, a total of 6,266 reports of adverse events after the puncture. This is equivalent to 205 reports per 100,000 doses administered, concludes the latest pharmacovigilance report on covid-19 vaccines, coordinated by the Spanish Agency for Medicines and Health Products (AEMPS).

The most common adverse effects to date they are fever (detected in 39% of cases), headache (29%), muscle aches (20%), pain in the vaccination area (13%), malaise (13%), nausea ( 10%) and chills (8%). Everything within the normal, then. “After reviewing the available data, no hitherto unknown adverse reactions have been identified that could be cause for concern”, Concludes the latest pharmacovigilance report, with updated information as of February 21.

92% of the vaccines administered to date in Spain bear the signature of Pfizer and BioNtech. The most extensive follow-up of cases, therefore, also corresponds to this formula. The latest scientific evaluation of the reported cases adds diarrhea and vomiting to the list of possible adverse effects of this formula, although for now the frequency with which they can occur is unknown.

When do symptoms appear and how long do they last?

The appearance of adverse effects depends on both the person and the vaccine. Clinical studies conducted to date suggest that young people tend to experience more severe adverse effects than the older ones. The mRNA vaccines (such as Pfizer and Moderna) tend to cause more discomfort after the second dose, while the AstraZeneca vaccine tends to cause more adverse reactions after the first puncture. According to the pharmacovigilance report, the adverse symptoms that appear after the vaccine are temporary and, in the vast majority of cases, they only last a few days.

“The discomfort depends on the resistance threshold of each person. There are people who with 38 fever cannot get out of bed and people who with 39 feel fine, “he explains. Jose Antonio Forcada Segarra, president of the National Association of Nursing and Vaccines (ANEV) and secretary of the Spanish Association of Vaccination (AEV) in an interview with this newspaper. “It is also true that, as this vaccine is new, we are all more aware of the adverse effects and there may be a certain nocebo effect“, Add.

Have people died from the vaccine?

The global vaccine balance speaks of more than 300 million doses delivered to date and almost 200 million citizens immunized against covid-19. The casuistry, therefore, is as extensive as the number of people vaccinated. But beyond the mild adverse effects, you are concerned about the possible occurrence of serious reactions that may eventually lead a patient to death. In Norway, for example, the health authorities opened a file to study whether the death of 33 residents in a nursing home could be related to the Pfizer vaccine they received a week earlier.

An analysis by the World Health Organization (WHO), the European Medicines Agency (EMA) and the Uppsala Monitoring Center (UMC) published at the end of January concludes that there is no direct relationship between these deaths and vaccines against covid-19. The deceased, therefore, would have died from complications of their own pre-existing diseases or from external causes and not from the injection against the coronavirus.

All the studies carried out to date on these vaccines show the same conclusion. The benefit-risk balance of these drugs suggests that, today, vaccines against covid-19 are a more than favorable option.


-What covid vaccines are given in Spain? Types and side effects

-Astrazeneca vaccine: side effects, where it is from, effectiveness and dosage

-Pfizer vaccine: side effects, where it is from, effectiveness and dosage

-Janssen vaccine: side effects, where it is from, effectiveness and dosage

-Modern vaccine: side effects, where it is from, effectiveness and dosage

-Sputnik vaccine: side effects, where it is from, effectiveness and dose

-This is the covid vaccination plan in Catalonia: calendar, groups …

Related news


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.