Claims like “SARS-CoV-2 vaccines make you infertile!” have been swirling around social media for months.
At first, it was women who had to worry most about their fertility after a COVID vaccine. And the proponents of the claim say they can explain it biologically.
They say that vaccines produce antibodies that not only attack COVID but also a protein that’s needed for a placenta to grow in the womb.
But scientists say it’s a myth.
This is how the vaccines work. Take mRNA vaccines, such as those by the companies BioNTech/Pfizer and Moderna.
The vaccines hold a “blueprint,” in the form of mRNA, for the bit of SARS-CoV-2, the virus that attaches itself to our cells and infects us: We’re talking about the so-called spike protein that pokes out of the surface (or membrane) of the virus.
When the body reads that blueprint, the body produces a version of the spike protein itself (Ed.: but not the harmful bits of the virus!) and that kickstarts an immune response.
The body produces antibodies to fight what it thinks is an invasion by the SARS-CoV-2 virus. And that then gives you a measure of protection against real attacks in the future.
The claims go on to suggest, however, that those antibodies attack another protein called Syncytin-1. It’s that protein that helps placentas grow in the womb and which is necessary for a successful pregnancy.
The reason, say those people peddling the claim, is that Syncytin-1 and the spike protein look similar.
But research shows the similarities are very small.
The SARS-CoV-2 spike protein consists of 1,273 amino acids, while the Syncytin-1 protein has 538. Researchers have so far only found one sequence of five amino acids that shows any similarity between the two proteins. Even that sequence is not totally identical. And that’s where the similarities end.
German researchers, such as Udo Markert and Ekkehard Schleußner of the University Hospital in Jena, Germany, have spoken out about the claims.
They say that if it was true that an immune response produced by a vaccine made you infertile, then it would also have to be true that a COVID-19 infection made you infertile.
Ekkehard Schleußner heads the Department of Obstetrics at the university hospital. And Markert heads its Placenta Lab. Markert is also the president of the European Society for Reproductive Immunology.
“As far as we’re concerned in the field of placenta research and reproductive medicine, these widely spread claims are totally unfounded!” write Markert and Schleußner in a joint statement (Ed.: links to German text).
They advise every woman to get a vaccine to protect against a COVID-19 infection and its still largely unknown long-term effects.
It’s not just women who are worried about these claims on social media. Some of the claims also target men, saying COVID vaccines affect male fertility negatively as well.
The researchers investigated sperm from 45 men before and after they had had a mRNA COVID vaccine, and they found no negative effects.
“We found no evidence to suggest any negative effects from a COVID vaccine on sperm among the men in our study,” Daniel Nassau told DW.
Nassau, who is a urologist and co-author of the study, said he was confident that a larger number of participants would have delivered the same result.
Meanwhile, another author of the study, Ranjith Ramasamy, has written in The Conversation that the real threat to fertility is a COVID-19 infection.
Ramasamy, who is a professor of urology at the University of Miami, writes that “contrary to myths circulating on social media, COVID-19 vaccines do not cause erectile dysfunction and male infertility.”
He and his team say they have proved it. They studied testis tissue collected from the autopsies of COVID-19 positive men and some who died for other reasons.
Ramasamy says their results show that it’s virus affects sperm production, fertility and can also cause erectile dysfunction.
But Ramasamy says the results are not surprising. Other viruses, such as mumps and Zika, can cause inflammation in the testes and that can affect fertility as well.
“The risk of infertility and erectile dysfunction increases with the severity of an infection,” says Nassau. “I strongly advise every man to get vaccinated.”
This woolly miracle started out in a test tube and was born on July 5, 1996, to three mothers – one provided the egg, the second the DNA and the third was the surrogate. Dolly was the world’s first mammal cloned from an adult cell. The sheep that made history lived to be six, when she was put down after developing a lung disease. Dolly is on display at Edinburgh’s National Museum of Scotland.
Idaho Gem is the very first cloned mule. Born in 2003 in – you guessed it – a town in Idaho, he is an identical genetic copy of his champion racing mule brother. Idaho Gem lived up to expectations and became a successful racing mule. Tougher and more productive than horses, mules are a – usually sterile – cross between a female horse and a male donkey.
The world’s first cloned pet was a cat. The Texas scientists who created the clone in 2001 called the furball CC, for carbon copy. Commercial pet cloning hasn’t taken off, however, much to the dismay of devoted pet owners.
Noel, Angel, Star, Joy and Mary were born on Christmas Day 2001 at PPL Therapeutics – which is the company that helped make Dolly the sheep: The five healthy female piglet clones, PPL said, had the genetic capability to allow their organs to be transferred to the human body without being rejected.
Injaz (“Achievement”) is the first cloned female dromedary, that is one-hump, camel. The gangly Arabian camel was born in 2009 at the Camel Reproduction Center in Dubai. Used for transport, riding and racing, camels still play an important role today in the Persian Gulf society.
Spanish scientists cloned a fighting bull they named Got. In this 2010 photo, the little fellow, cloned from the tough fighting bull Vasito, doesn’t look ferocious yet at all. Got’s mom was a serene black and white milk cow surrogate.
Unlike Dolly, who was created using a procedure called nuclear transfer, little Tetra the rhesus macaque was created through a technique called embryo splitting. In 2000, scientists in Oregon presented the little primate they had successfully cloned for the first time. Above, Tetra, which means four in Greek, is four months old.
A team of researchers in South Korea managed to clone the first canine in 2005: the Afghan hound Snuppy. In 2014, a biotech company based in Seoul cloned another dog, this one from a 12-year-old dachshund that belongs to a caterer in London who won the procedure in a competition. The result: Mini-Winnie. Experts, however, warn of cloning pets, arguing the animals won’t necessarily be the same.