Two years of misinformation about COVID-19 vaccines

Misinformation about COVID-19 vaccines is a global phenomenon that fuels public mistrust and contributes to undermining vaccination campaigns.

The main mechanism of misinformation is to exaggerate side effects or even make them up to make people believe that vaccines are more dangerous than COVID-19.

Distorted figures on the “side effects”

Like any medical device, COVID-19 vaccines can have side effects, but countless social media posts exaggerate their number and severity.

The same procedure is often used: misusing numbers to scare people, as French MP Martine Wonner recently did.

He cited figures from the US VAERS system, which records every time someone reports a possible vaccine-related side effect.

But these data do not indicate any relationship between cause and effect: they can “contain incomplete, inaccurate, incidental or unverifiable information”, warns VAERS itself on its website.

In most countries, any citizen or health worker can point out a possible side effect, but it is up to the health authorities to determine if the vaccines are to blame.

Only in very few cases (out of a total of billions of injected doses) did health authorities consider a causal relationship between a vaccine and a health problem, such as myocarditis, pericarditis, or atypical thrombosis, to be possible.

But the benefit/risk balance remains largely in favor of vaccines.

Risks without scientific basis: immune system, AIDS and DNA

The theory that vaccines weaken or even destroy the immune system is a classic anti-vaccine argument, one that has resurfaced during the pandemic.

In early January, some publications even claimed, without any scientific basis, that “fully vaccinated people will develop AIDS.”

However, the scientific community has repeatedly denied this claim: on the contrary, vaccines are used to strengthen the immune system so that the body can quickly and effectively fight pathogens, in this case Sars-CoV-2, the virus responsible for COVID-19.

Another recurring misinformation is that injections “make you sterile”. Experts from around the world have explained that this idea is not based on any scientific data and that there is nothing in the vaccine that can cause sterility.

The theory that messenger RNA vaccines change the genome is another of the “greatest hits” of anti-vaccine misinformation.

But it is totally impossible, among other reasons because the vaccine’s messenger RNA does not reach the nucleus of the cell, where the DNA is found.

Many vaccinated among those infected?

Statistics on those vaccinated, infected and hospitalized are regularly distorted or taken out of context to claim that vaccines are useless.

Many Internet users maintain, for example, based on official figures, that in France there are more infected vaccinated than unvaccinated in absolute numbers.

But this does not prove that vaccines are useless.

Regardless of the statistics, it must be taken into account that in France more than three quarters of the population is vaccinated, and even more in certain age groups.

At the same time, as has been known since the launch of vaccines, they do not totally prevent infection and transmission of the virus.

Therefore, it is mathematically inevitable that the proportion of vaccinated people will be very high among those infected.

In a theoretical example, if 100% of a population is vaccinated, 100% of those infected or even hospitalized (even if they are few) will also be vaccinated.

This does not provide any good or bad information about the vaccine. This is a calculation well known to statisticians, called “Simpson’s paradox”.

Therefore, it is necessary to reason in terms of equal population groups and not in absolute numbers.

Thus, it is observed that the positives, hospitalizations and deaths are “clearly more important for unvaccinated people than for vaccinated people in a comparable population”, as the statistics unit of the French Ministry of Health explains.

The arrival of the highly contagious omicron variant has also fueled misunderstandings of the statistics.

The fact that among people infected with COVID-19, those who are vaccinated are mostly infected with the omicron variant has led some to conclude that vaccines increase the risk of infection.

Actually, if omicron predominates in the vaccinated, it is because the vaccines are less effective against omicron than against delta.

So when a vaccinated person gets infected right now, it’s mostly omicron.

The unvaccinated infected are not only affected by omicron but also –much more than the vaccinated– by delta. And they are not protected against severe forms of the disease.