Despite the evidence against false and misleading claims that Covid-19 vaccines harm fertility and cause miscarriages, hearsay continues to circulate online.
Initially, doctors had advised avoiding the jab due to insufficient study claiming the vaccines as safe during pregnancy.
But now, with enough safety data available – advice has changed and the vaccine is now actively encouraged (as getting Covid can put a pregnancy at risk).
BBC looked at some of the more persistent claims – and why they are wrong.
Vaccine accumulating in the Ovaries – a misreading of a Japanese study
The study involved giving rats a dose of vaccine, 1333 times higher than that given to humans. Only 0.1% of the total dose ended up in the animals’ ovaries, 48 hours after injection.
The vaccine is delivered using a bubble of fat containing the virus’s genetic material, which kick-starts the body’s immune system.
And those promoting this claim cherry-picked a figure which actually referred to the concentration of fat found in the ovaries.
As the vaccine contents moved from the injection site around the body, fat levels in the ovaries did increase in the 48 hours after the jab. But, crucially, there was no evidence it still contained the virus’s genetic material.
Monitoring data shows vaccines cause miscarriages – another false claim
Some posts have highlighted miscarriages reported to vaccine-monitoring schemes. Anyone can report symptoms or health conditions they experience after being vaccinated. Not everyone will choose to report, so this is a self-selecting database.
There were indeed miscarriages reported in these databases – common unfortunate occurrences – but this does not mean the vaccine caused them.
A study has found data showing the miscarriage rate among vaccinated people was in line with the rate expected in the general population – 12.5%.
Dr Victoria Male, from Imperial College London, says these reporting systems are very good for spotting side-effects from the vaccine that are normally rare in the general population – like the type of blood clot linked to AstraZeneca in rare cases.
However, they are not so good at monitoring side-effects that are common in the population – such as changes to periods, miscarriages and heart problems. Seeing them in the data doesn’t necessarily raise these red flags because you’d expect to see them anyway, vaccine or not.
Vaccines could attack the placenta – not backed up with evidence
Michael Yeadon, a scientific researcher, claimed that the coronavirus’s spike protein contained within the Pfizer and Moderna vaccines was similar to a protein called syncytin-1, involved in forming the placenta.
He speculated that this might cause antibodies against the virus to attack a developing pregnancy, too.
Some experts believe this was the origin of the whole belief that Covid vaccines might harm fertility.
In fact, syncytin-1 and the coronavirus’s spike protein are just about as similar as any two random proteins – if the body was that easily confused, it would risk attacking its own organs every time it caught an infection and developed antibodies.
But now evidence has been gathered to help disprove his theory.
US fertility doctor Randy Morris, who wanted to respond directly to the concerns he’d heard, pointed out that people spreading these fears had not explained why they believed antibodies produced in response to the vaccine could harm fertility but the same antibodies from a natural infection would not.
As Dr Morris explained: “The hallmark of a conspiracy theory is as soon as it’s disproven, you move the goalpost.”
Also Read: WHO Validates Sinovac COVID-19 Vaccine
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