Does the vaccine cause infertility? Does a cured infection or a vaccine protect better?

Numerous claims about the harmfulness of some vaccines against COVID-19 are spreading on the Internet, and the most common ones are that vaccines cause infertility and that the immunity acquired by recovering is better than the one acquired after vaccination.

Can women become infertile due to vaccination?

According to the anti-vax theory, after vaccination, antibodies are allegedly attached not only to the spike-protein of the coronavirus, but also to a similar protein, syncytin 1. This protein plays a role in the development of the placenta. If that protein is disabled as a result of vaccination, it could lead to infertility in women, say the proponents of that theory.

"There are many reasons why that theory cannot be correct," he claims in an interview with Deutsche Welle Udo Markert, head of the Placenta Laboratory of the University Clinic in Jena. The similarity between the two proteins is very small, only 0,75 percent, he says.

With the drug against multiple sclerosis, scientists have already investigated the unwanted interaction between antibodies and syncytin 1. The drug was supposed to work against a protein that is 81 percent similar to syncytin. And the result was that there was no mention of worthwhile interactions.

Markert believes that in that case, infection with the coronavirus would pose an even greater threat to women's infertility, but notes that during the SARS epidemic in 2002/2003. no link between infection and infertility was established, although the spike protein of that virus was almost identical to the spike protein of the SARS-CoV-2 virus.

The British Fertility Society states that there are "no indications or theoretical grounds for the connection of female or male infertility with vaccination against COVID-19".

Does a recovered infection protect against new infection better than vaccination?

The fact is that most people infected with the coronavirus pass with mild symptoms or no symptoms at all. According to the Roberta Koch Institute in Germany, in the first wave of infection in the spring of 2020, about 80 percent of those tested positive had weak or no symptoms. The other 20 percent had a more severe or critical course of the disease.

But there is no guarantee that people who do not have an increased risk of a severe course of the infection will actually pass without more serious consequences. It happens that young and healthy people tend to get sick and some even die from it. And there are long-term consequences such as chronic fatigue or problems with blood flow that occur even in those who had a mild course of the disease.

Vaccines should stimulate the body to create antibodies. It is not yet known how long these effects will last, says Reinhold Förster, vice president of the German Society for Immunology in an interview with DW. If a person prefers to risk infection rather than get vaccinated, he is taking a "big risk", says Förster.

Another reason in favor of vaccination is that the immune system reacts differently to vaccination. "This longer-term safety from infection could be more pronounced with the help of a vaccine," says virologist Christian Drosten. Because it seems that more antibodies are created after vaccination and that they remain in the body longer.

This is also confirmed by Förster based on his own unpublished research. "Essentially, it is about the quantity and quality of antibodies created. Quality is primarily about the antibody's ability to stay attached to the protein and thus prevent infection." Both had higher values ​​after the second injection of the BioNTech/Pfizer vaccine than after infection, Förster says, writing German wave.