mRNA vaccines are not a birth control operation

None of the vaccines against covid-19 has the capacity to produce infertility or deactivate the immune system


A website self-defined as catholic has published an article attacking messenger RNA (mRNA) vaccines, such as those from Pfizer or Moderna, for using a technology that, acoording to them, is able of “turning off the immune and reproductive system in humans only with pushing a switch”. This is a FALSE statement. mRNA vaccines can not produce infertiliy or deactivate the immune system. In fact, none of the vaccines against covid-19 has this capacity.

"mRNA can not be used to turn off the immune and reproductive system by only pressing a switch"

mRNA vaccines have a list of side effects, but infertility or the immunse system inactivation are not found among them. On the contrary, what injections indeed do is precisely to generate antibodies to combat the disease caused by SARS-CoV-2.

It is not the first time that something similar about the alleged effec t of the vaccine on infertility is said. Immunologist Adelaida Sarukhan, scientific writer at the Barcelona Institute of Global Health (ISGlobal in Catalan) rercalls how this hoax has been circulating for months and that it arose because of the statements of a German doctor and of a Pfizer former employee, who said that “the SARS-CoV-2 Spike protein shared similar regions with a human protein called syncytin-1, which is found in the placenta”. That is, according to him, involved that “the anti-spike antobodies generated by the covid-19 vaccine could attack the placenta and cause infertility”.

An argument without scientific evidence

There is no scientific evidence supporting this argument: “the sequence shared by both proteins is very small”, summarises the immunologist, who cites the example of Jill Foster, paediatrician from Minnesota University: “It is as if two telephone numbers shared one or two digits. This does not mean that we can call a person dialing another number”, she concludes.

On the other hand, no infertility case have been yet notified, either in the different phases of the clinical trials or along the vaccination campaign. Not even in women who have had the disease, for whom “natural infection also induces the production of these antibodies”, Sarukhan reasons.

It is more likely that SRS-CoV-2 itself causes infertility

It is also not expected that the rest of vaccines against covid-19 cause fertility problems, as lregulatory agancies have confirmed in authorising their use: “No approved vaccine (up to now in the world) causes alterations in fertility. It is more likely to have alterations in fertilitty due to the natural injection (of the virus), than due to the vaccines theirselves”, has affirmed Julià Blanco, who is leading the Virology and Cell Immunology group at the IrsiCaixa research Institute.

As the scientists points out, SARS-CoV-2 uses the ACE2 enzyme to enter our body, a human protein regulating angiotensin hormone, which in turn adjusts, among other things, blood pressure. A study analysing the virus consequences of fertility colncludes that male gonads could be mor sensitive to the infection and recommend caution to women and couples planning to have children.

Are there vaccines causing infertility?

The article also ensures that there is a campaign to sterilise young women in Africa by means of the tetanus or the human papiloma vaccine. However, infertility is not a common side effect of vaccines: “As far as I know, there is no any vaccine in history that has caused it”, Sarukhan admits. “At one time, there was also a rumour circulating that the HPV vaccine might cause infertility, but studies indicate no association" between the two. 

What do exist (in very preliminary stages) are vaccines designed specifically for fertility control as a method of contraception. They fall into what is known as immunocontraception, a recent research line that is still being explored. These vaccines would work "by inducing antibodies directed against different proteins expressed by eggs, sperm or sex hormones," summarises Sarukhan.