Vaccines are not ‘poison’

A post on Facebook has claimed that “vaccines are all poison”. That’s not the case. While vaccines may have some side effects, they are not poisonous and can be a safe and effective means of keeping yourself and others protected from diseases.

All vaccines in use in the UK are monitored for side effects by the Medicines and Healthcare products Regulatory Agency (MHRA) to ensure they remain safe to use.

Medical practitioners and members of the public are also able to report their own suspected side effects of a vaccination to the MHRA via the Yellow Card scheme.

Vaccine misinformation can cause direct damage to people’s physical or psychological health, and can put particular communities and vaccine coverage levels at risk.

If it spreads at scale it can introduce confusion about the causes and treatments of illnesses, create distrust of medical professionals, and distract from or undermine medical consensus and public health messaging. 

Risks and benefits of vaccination

The NHS says that “vaccines are the most effective way to prevent many infectious diseases”.

A recent study from the World Health Organization (WHO) found that over the last 50 years, global immunisation has saved an estimated 154 million lives, including 101 million children.

In the UK diseases such as smallpox, polio and tetanus are either all but eradicated, very rarely seen or significantly less harmful than they have been previously.

Vaccines can cause side effects. However the NHS says that most side effects are “mild and do not last long”.

These often include a swelling or pain around the injection site, a high temperature, feeling feverish and flu-like symptoms.

It is also possible, although rare, for someone to have an allergic reaction to a vaccine, which may also cause concern. This will usually happen within minutes of receiving the vaccine and the person giving the vaccine will be trained to treat this.

Vaccine safety

Vaccines are rigorously safety tested before they are introduced to the wider population and are constantly monitored for adverse effects.

According to the Vaccine Knowledge Project at the University of Oxford, the standard for testing and monitoring of vaccines is higher than it is for most other medicines because they are given primarily to healthy people and children.

Vaccines typically go through a number of phases during testing, in groups of increasing size. These phases will look to identify any safety concerns, possible side effects and see how effective the vaccine is.

After a vaccine has been licensed and is in use, it will be consistently monitored by the MHRA.

Based on the outcome, information on the vaccine may be updated or, in more severe cases, the MHRA may issue a warning to prevent its use among specific groups of people.

Rarely, the vaccine may be withdrawn from use if it is necessary to do so.

Specific ingredients

Full Fact regularly checks claims about specific vaccine ingredients.

Often, these ingredients are used in the manufacturing process—and so are not in the final vaccine—or are present in such small quantities that they aren’t harmful.

You can read more about our work checking vaccine claims on our Vaccines page.