At every stage, the coronavirus pandemic has been marked by false claims, conspiracy theories and opportunistic scams.

We all deserve better than bad information. That's why we’re taking part in this year’s Big Give Christmas Challenge to help create a more honest 2021.

From 1-8 December you'll be able to donate to help us reach our target, and any amount you give will be matched by Full Fact's pledgers, meaning your gift will have double the impact.

But it's a huge target for us, and we need as many people involved as possible. Can you help our campaign go further? 

Share it with someone who agrees that honesty matters:

Our readers asked us to look into two claims:

• That aluminium used in a new Covid-19 vaccine—or any other vaccine—can cause Alzheimer’s disease
• That new Covid-19 vaccines contain enough mercury to cause brain damage. 

The amount of aluminium used in human vaccines is incredibly small, and typically weighs in at less than a milligram (between 0.2 and 0.8mg), and most aluminium taken into the body is cleaned out by the kidneys.

By comparison, an adult typically ingests seven to nine mg of aluminium per day in food like fruit, vegetables, cereals and beer and wine. Concerns about mercury in vaccines probably relates to thiomersal, a mercury-based chemical.

There are two types of mercury to which people may be exposed: methyl mercury and ethyl mercury. Methyl mercury can be toxic to people but ethyl mercury, which is in thiomersal, is quickly eliminated from the body so it does not build up to reach harmful levels. Besides, ethyl mercury is no longer used in most vaccines in the UK, Europe or the US.

In a now-deleted tweet, writer and commentator Toby Young wrongly claimed a study published in Royal Society Open Science, found that Covid-19’s infection fatality rate (IFR) is just 0.1%, which he said was comparable to seasonal flu.

As many people on Twitter had pointed out, and Mr Young subsequently acknowledged, his calculation for the IFR of Covid-19 was incorrect.

If over 5 million people had caught the virus in the UK by August, as the study argued, and you then applied the current death toll of around 50,000 people, you would get an IFR of around 1%, not 0.1%. (The current figure for deaths within 28 days of a positive test is over 52,000).

However, it’s worth noting that both the study and the Daily Mail article Mr Young cited had already assumed an infection fatality rate of 0.76%. In fact, that’s how the study calculated its figure for how many people in the UK have been infected—by “backcasting” from death figures up to the end of August and applying an estimated IFR.

• Ticketmaster won’t demand proof of a Covid-19 vaccine for concert entry
• No, contact tracing doesn’t cost £10,000 per contact
• How accurate are the new rapid lateral flow tests?
• New data doesn’t definitively show zero increase in suicides across England