Vaccine and…fertility

The newest misinformation circulating the web. In short, some people are shouting that COVID19 vaccine will cause infertility. This claim is baseless. And, unfortunately, the claim is folded within some complex scientific terms, making it the most dangerous form of misinformation.

Briefly, the COVID19 vaccine causes you to develop antibodies. If you come in contact with COVID19 virus after getting the vaccine, these antibodies will attach to the spike on the COVID19 virus. Once attached, the virus is no longer able to attack the body. The misinformation is claiming that COVID19 antibodies also attach to spikes (called proteins) on the placenta (called syncytins).

There are a few strong reasons to doubt this claim…

1. You should know that infertility is a common fear tactic of anti-vaxxers. We’ve seen this over and over again (HPV, Hep B,…). In fact, some developing countries still have polio because of the widespread fear that polio vaccines cause infertility. We, actually, should not be surprised that this is the next wave of pandemic misinformation. Misinformation is becoming almost as predictable as the disease itself.

2. Those that are “naturally” infected with COVID19 (i.e. not vaccine) also have antibodies. If this misinformation were true, we would be seeing a higher than average early pregnancy loss in the community overall. We are not. Although COVID19 seems to be a more severe disease in pregnancy (it’s been consistently on the high-risk CDC list), all complications happen later in pregnancy (particularly from lung function, not the placenta). There are a few case reports discussing early pregnancy losses in patients with COVID19. But case reports are just one or two people. They just tell us that they co-occurred, not that they are related. There is no strong evidence that COVID19 antibodies increases early pregnancy loss among symptomatic or asymptomatic women.

3. The spike proteins on the placenta and on the virus are in the same family, so they work the same way. HOWEVER, they aren’t similar enough (i.e. they don’t have enough amino acid sequences) to cause confusion to the immune system. In other words, the immune system cannot and will not mistake the placenta for the virus.

IN ADDITION, it’s important to note that COVID19, itself, is affecting women’s and men’s reproductive health. We DO have the evidence for this. Not to mention that COVID19 also causes chronic inflammation, which is also associated with decreased fertility. So, getting COVID19 is certainly not a great second choice if you don't get the vaccine.

Love, YLE

Data Sources: I consulted several public health rock stars and biochemistry scientists on this topic. For those of you that like the hard science, here is a great post: And here are the publications re: COVID19 and fertility