Claims Covid-19 vaccine harms ferility unfounded


Claims Covid-19 vaccine harms ferility unfounded

Posts have incorrectly suggested the Pfizer vaccine could cause infertility in women, or cause their bodies to attack the placenta.

Posts have incorrectly suggested the Pfizer vaccine could cause infertility in women, or cause their bodies to attack the placenta.

But there is no "plausible biological mechanism" by which the vaccine could affect your fertility, says Prof Lucy Chappell, a professor in obstetrics at King's College London and spokesperson for the Royal College of Obstetricians and Gynaecologists.

How does the vaccine work?

The vaccine works by sending a message to the body with a blueprint, allowing it to manufacture a small, harmless fragment of the coronavirus's distinctive "spike".

This prompts your immune system to kick into action, producing antibodies and white blood cells to fight off the virus - and recognising it if you encounter it again.

It can't give you the virus, and it has no way of affecting your own genetic information.

These "messenger particles" are extremely short-lived: they deliver their message and then they are destroyed. That's why the Pfizer vaccine in particular has to be stored so carefully - genetic material falls apart and becomes useless very easily.

Prof Nicola Stonehouse, a virologist at the University of Leeds, said there was no possible way she could think of that this could have an impact on reproductive health.

What does the evidence say?

Online, some people have pointed to a line in an earlier version of guidance published by the UK government stating it was "unknown" whether the Pfizer vaccine had an impact on fertility. This has since been updated to clarify that animal studies don't indicate any harmful effects on the reproductive system.

Part of the confusion here is down to how scientists describe things compared with how most of us would understand them in our daily lives.

When scientists say there is "no evidence" they mean there hasn't yet been a long-term study on this specific vaccine - but that doesn't mean there are no facts here at all or we're shooting in the dark.

In fact, Prof Chappell pointed out, there is lots of evidence from other non-live virus vaccines, including the flu jab, that they have no impact on fertility and are completely safe and recommended for use during pregnancy.

And getting the Covid virus itself - which the vaccine protects against - could affect fertility, so "you're much more likely to have fertility issues post-Covid than after the vaccine," Prof Stonehouse said.

False placenta claims

Some of the rumours have suggested the vaccine could threaten fertility because it contains proteins also used to make the placenta. Posts on social media have claimed this could lead the body to attack the placenta.

This is not true - the vaccine does contain a protein which slightly resembles one used in the development of the placenta but it's not similar enough to confuse the body.

Vaccines are designed around the most distinctive parts of the virus's spike to make sure it recognises only that.

The fact that the respective proteins bear a passing resemblance "doesn't mean anything", says Prof Chappell, since there are lots of similar proteins existing in different places in nature - it's their precise length and sequence that makes them distinctive.

Prof Chappell, who specialises in the health of pregnant women and people hoping to conceive, said she had "no concerns" about fertility and the Covid vaccine.

And the deputy chief medical officer for England, Jonathan Van-Tam, when answering questions from BBC viewers, said: "I have never heard of a vaccine that affects fertility."