The Pfizer-BioNTech COVID-19 vaccine may sometimes cause no side effects or mild to moderate side effects, which can be quite common after vaccination. This Snapshot feature further addresses concerns about allergic reactions and false claims regarding risks to pregnancy and fertility.
Sex and gender exist in spectra. This article will use the terms “male” and “female” to refer to the sex assigned to a person at birth.
The Pfizer-BioNTech COVID-19 vaccine, called BNT162b2, and known as Comirnaty in the European Union, is a two-dose mRNA vaccine developed by two companies in the pharmaceutical industry: Pfizer in the United States and BioNTech in Germany.
In December 2020, the Food and Drug Administration (FDA) trusted source and the World Health Organization (WHO) trusted source authorized the vaccine for emergency use in people over 16 years of age, making it the first COVID-19 vaccine to receive authorization for emergency use. by any of the organizations. Currently, the vaccine is approved in 82 countries.
This mRNA vaccine works by providing the body with a set of instructions to create the spike protein found on the surface of the SARS-CoV-2 virus. The presence of the protein antigen in the body causes the immune system to produce antibodies, which prepares the body to fight future infections from the virus itself.
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However, the vaccine does not contain the virus and cannot cause infection. Furthermore, the mRNA in the vaccine does not have the ability to alter DNA within cells, as it is a transient molecule and does not enter the nucleus where the DNA is stored.
Although mRNA vaccines have been studied for many years, they have never been approved for human use against disease before. As a result, members of the public have raised concerns regarding potential unknown side effects.
Common side effects
According to the FDA Vaccine Fact Sheet, a trusted source, typical side effects of the Pfizer-BioNTech vaccine include:
- shaking chills
- muscle or joint pain
- swollen lymph nodes
People have also reported injection site side effects, such as arm pain, redness, and swelling.
These side effects are often signs that the vaccine is working, inducing a protective response from the immune system.
Many people who received both doses of the vaccine have reported that symptoms are more prominent after the second dose. However, in most cases, these have been mild to moderate and do not last more than a few days.
Concerns about pregnancy and fertility
Concerns about the effects of the vaccine on fertility arose when an Internet source stated that the genetic information of the spike protein is similar to that of syncytin-1, a protein found in the placenta of mammals.
The source, now removed from the web, claimed that antibodies produced by the body in response to the vaccine, which targets the spike protein of the SARS-CoV-2 virus, could also attack syncytin-1 and cause infertility.
Scientists have shown this claim to be inaccurate. First, immunologists have not shown significant similarities between the genetic information of these two proteins, while the blood plasma of COVID-19 patients does not react with syncytin-1.
Second, if this statement were true, it would mean that natural SARS-CoV-2 infection would likely cause a higher rate of miscarriages. This has not been seen in studies examining the effects of COVID-19: female participants with the disease did not show an increased risk of early pregnancy loss.
Additionally, clinical trials of the vaccine included 11 women participating in the vaccinated group who became pregnant during the trial, compared with a similar number of 12 women participating in the control group.
While there is no long-term evidence yet regarding this claim, animal studies have also not reflected any evidence of loss of fertility due to the vaccine.
Pfizer and BioNTech are also conducting clinical trials in pregnant women to look at the effects of the vaccine on both pregnant women and their babies.