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Debunked: No, unvaccinated people can't get health problems from being around those who are vaccinated

The claim is being made and shared online – with people claiming ‘vaccine shedding’ is happening.

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CLAIMS ARE BEING made and shared online that the Covid-19 vaccines can affect the health of people who have not been vaccinated, just by being around people who have received a vaccination.

The claims typically posit that vaccinated people can ‘shed’ the vaccine, and that by spending time with vaccinated people, unvaccinated people can become ill, experiencing symptoms like nose bleeds or irregular menstrual cycles.

The claims we have seen online typically say that a person who has been unvaccinated can experience symptoms such as rashes, nose bleeds or irregular periods after being in contact with a vaccinated person. No claims we saw described the person experiencing Covid-19 symptoms.


Some proponents of the claim believe that those who have not had the vaccine should stay away from people who’ve been vaccinated. One claim being made is that the vaccine is “coming out through breath… through pores”.

The same woman who made this claim said that some unvaccinated people had experienced strange bruising caused by ‘shedding’ from vaccinated people, and that pets had died after being exposed to vaccinated people. 

Among the claims shared on Facebook:

“If you are of childbearing age please be aware that hundreds of women have been reporting major menstrual and cycle changes, pain, clotting, simply from being AROUND people who have had it. It looks like it’s the spike protein.”
“It’s a literal ‘covid rash’ and can only be gotten if you are in close proximity to someone who got recently vaccinated and you’re sharing bodily fluids.”

The ‘spike protein’ mentioned above is explained by Dr Seamus Lennon here, in relation to mRNA (messenger RNA) vaccines: 

“When introduced to patients, the RNA is taken up by the patient’s cells, and this RNA then produces the spike protein, which is displayed on the cell surface. Immune cells recognise the spike protein as foreign and manufacture antibodies against it.

“Thus, if the patient is subsequently exposed to coronavirus, antibodies will be produced rapidly which will neutralise the virus, and Covid-19 will not develop.”

To get to the bottom of these claims about shedding, The Journal spoke to Dr Kim Roberts, virology lecturer and assistant professor at Trinity College, Dublin, in its Department of Microbiology. She leads its Virology research group. 

  • What is typically meant by ‘virus shedding’?

Typically “virus shedding” in the context of vaccines refers to the small amount of vaccine-derived virus that can sometimes be released from a vaccinated person, after they have had a live-attenuated or live-weakened vaccine.

Examples of this type of vaccine are the nasal spray seasonal influenza vaccine that was offered to kids this winter and the oral polio vaccine that is no longer used in Ireland, which people used to get on their tongue (or on a sugar lump if they were lucky).

It’s important to remember though that these weakened vaccine viruses have been altered so that they do not cause disease, but they are very good at stimulating a good, long-lasting immune response that protects people from the disease-causing versions of virus that people can be exposed to in the community.

Most of the vaccines we use today do not contain replicating virus and so vaccinated people do not shed virus or viral proteins from these vaccines.

These include vaccines that contain inactivated or “killed” virus like the current polio vaccine, or virus which can’t replicate like the Astrazeneca COVID-19 vaccine.

There are also vaccines that only contain protein separated from virus, like the seasonal influenza vaccine that is injected into the arm, or the HPV vaccine.

  • Do mRNA Covid-19 vaccines shed? What about non-mRNA vaccines like AstraZeneca?

The mRNA vaccines are a new way of delivering viral protein into cells to stimulate the immune response. The mRNA acts as the recipe so that your cells make the protein themselves.

This is thought to stimulate a stronger immune response than simply delivering the viral protein readymade. However, your cells are not able to make more copies of the mRNA and the mRNA does not last very long in the cells.

One of the developmental hurdles in creating the mRNA vaccines has been the difficult job of delivering the mRNA into cells before the body can destroy it.

There is no evidence that vaccine-derived mRNA or viral spike protein is excreted from vaccinated people.

  • Could a vaccine ‘shed’ a spike protein?

There is no evidence that vaccine-derived SARS-CoV-2 spike protein is excreted from vaccinated people.

It’s worth remembering that the current COVID-19 vaccines do not use live or killed virus, but rather they only express the viral surface spike protein which does not cause disease.



Only the replicating whole virus is infectious and can cause disease.

  • Could a vaccine ‘shed’ and affect a person who spends time with a vaccinated person?

In limited circumstances, live-weakened vaccine viruses can be passed to people who have not been vaccinated.

For example, the nasal spray influenza vaccine has been found to be released from nasal secretions of young vaccinated children for a week or so, but this is still the weakened virus and does not cause disease.

Similarly, weakened poliovirus from the oral poliovirus vaccine can be found in the faeces of vaccinated children.

This can cause problems for people who are severely immunocompromised, or in very rare circumstances adults who have never received the polio vaccine – and this is why the oral polio vaccine has been phased out as the world gets closer to eradicating polio.

The current COVID-19 vaccines use either mRNA or non-replicating virus to present the coronavirus surface spike protein to your immune system. These are not contagious and cannot be transmitted to other people.

  • Could a vaccine ‘shed’ and affect the menstrual cycle of an unvaccinated person?

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There is no evidence from the clinical trials or the ongoing surveillance that COVID vaccines affect menstruation or fertility.

  • Can a vaccinated person somehow affect the health of an unvaccinated person?

When it comes to killed, protein-only or mRNA vaccines, these are not contagious and cannot be transmitted to non-vaccinated people. The current COVID-19 vaccines use either mRNA or non-replicating virus to present the coronavirus surface spike protein to your immune system. These are not contagious and cannot be transmitted to other people.


As Dr Roberts’ responses show, the claims that unvaccinated people became ill, experienced nosebleeds or had irregular menstrual cycles as a result of being around vaccinated people, are physically not possible.

If these things did happen, as claimed, it would not have been due to being in proximity to a vaccinated person.

Regarding the impact of the virus on the menstrual cycle for those who have been vaccinated, there has not been data linking the vaccines to changes in menstruation so far – but scientists have been calling for more work to be done in this area. An associate professor at the University of Illinois is doing a survey of whether people have experienced changes in menstruation post-vaccine, but no other large-scale study has been released so far.

And regarding fertility and the vaccine, at a recent NPHET briefing Dr Cliona Murphy said:

“We are aware of misinformation about risks associated with taking Covid-19 vaccines and an impact on fertility. There is no evidence that taking any of the Covid-19 vaccines affects a woman’s future ability to conceive, or to continue a pregnancy.” 


There is a lot of false news and scaremongering being spread in Ireland at the moment about coronavirus. Here are some practical ways for you to assess whether the messages that you’re seeing – especially on WhatsApp – are true or not. 


Look at where it’s coming from. Is it someone you know? Do they have a source for the information (e.g. the HSE website) or are they just saying that the information comes from someone they know? A lot of the false news being spread right now is from people claiming that messages from ‘a friend’ of theirs. Have a look yourself – do a quick Google search and see if the information is being reported elsewhere. 

Secondly, get the whole story, not just a headline. A lot of these messages have got vague information (“all the doctors at this hospital are panicking”) and don’t mention specific details. This is often – but not always a sign – that it may not be accurate. 

Finally, see how you feel after reading it. A lot of these false messages are designed to make people feel panicked. They’re deliberately manipulating your feelings to make you more likely to share it. If you feel panicked after reading something, check it out and see if it really is true.’s FactCheck is a signatory to the International Fact-Checking Network’s Code of Principles. You can read it here. For information on how FactCheck works, what the verdicts mean, and how you can take part, check out our Reader’s Guide here. You can read about the team of editors and reporters who work on the factchecks here

Have you gotten a message on WhatsApp or Facebook or Twitter about coronavirus that you’re not sure about and want us to check it out? Message or mail us and we’ll look into debunking it. WhatsApp: 085 221 4696 or Email:

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