The government hasn’t admitted Covid-19 vaccines damage your natural immune system

A screenshot of a tweet posted on Instagram claims: “The UK government now oddly admits the vaccines have damaged the natural immune system of those who have been double-vaccinated”. A paraphrased version of the claim has also appeared on Facebook.

The UK government has said no such thing. This may be based on two separate misinterpretations of data from the UK Health Security Agency (UKHSA).

The UKHSA publishes weekly “vaccine surveillance reports” but none have said that vaccines have damaged natural immunity in those who have been double vaccinated

Part of these reports show the number of people infected with Covid-19 in England, who both have and have not been vaccinated. Data appearing to show higher case rates among vaccinated people has previously been misinterpreted as showing the vaccines have negative effectiveness in certain age groups, or that they are damaging natural immune systems. We have fact checked similar claims many times before.

But this data cannot be used to determine whether vaccinated or unvaccinated people are more likely to catch Covid. We don’t know exactly how many people haven’t been vaccinated, because that figure relies on unreliable estimates of the population size, so we can’t really compare Covid-19 case rates among vaccinated and unvaccinated people. 

We explain this misinterpretation in more detail here, but the UKHSA says that comparing its reports’ case rates among vaccinated and unvaccinated populations shouldn’t be used to estimate vaccine effectiveness.

It warns: “The vaccination status of cases, inpatients and deaths should not be used to assess vaccine effectiveness because of differences in risk, behaviour and testing in the vaccinated and unvaccinated populations. 

“The case rates in the vaccinated and unvaccinated populations are crude rates that do not take into account underlying statistical biases in the data.”

The tweet may be referring to something else. A reply from another Twitter user points to an older version of the UKHSA report, and claims this is proof of the claim that Covid-19 vaccines damage the natural immune system. Examples of the claim on Facebook suggest this too.

Both point to part of a UKHSA report from October which mentions “recent observations from UK Health Security Agency (UKHSA) surveillance data that N antibody levels appear to be lower in individuals who acquire infection following 2 doses of vaccination”.

Earlier in this report, it’s explained that the UKHSA has two types of tests for Covid-19 antibodies in samples from blood donors:

• Roche nucleoprotein (N) tests, which only detect post-infection antibodies, and
• Roche spike (S) tests, which will detect both post-infection antibodies and vaccine-induced antibodies.

So the week 42 report is saying that the antibodies detectable post-infection are lower in those who are infected after two doses of the vaccine. This doesn’t mean that the vaccine has damaged their natural immune system. The same report showed that the percentage of blood donors with antibodies detectable both post-infection and post-vaccine increased over time before plateauing at over 96%, and the vaccine roll-out has been an “important contribution to that”.

In fact, we have lots of data showing that the Covid-19 vaccines do reduce your chances of having symptomatic Covid-19, being hospitalised for it, and dying of it. (The extent of effectiveness does seem to vary depending on the variant.)

Reuters fact checked these claims when they first emerged last year, and concluded the same thing, that just because there were lower levels of a certain post-infection antibody in those who’d been vaccinated and had caught Covid-19, doesn’t mean their immune system was damaged.