NICOLAS TUCAT via AFP
VACCINES – Is vaccination ineffective against Covid? It is that recently suggested its detractors like Florent Philippot on Twitter, supporting statistics. On what basis?
In England, a briefing by Public Health England (PHE) published on June 25 indicates that the majority of recent deaths linked to Covid have been observed in vaccinated people. Of 117 deaths of patients affected (over the period studied) by the Delta variant, 50 were fully vaccinated and 20 had received only one dose. In Israel, 40% of new infected people are vaccinated according to Cnews, reporting the words of a former director general of the Israeli Ministry of Health.
However, these figures do not mean that the vaccines are ineffective, a simple mathematical calculation allows on the contrary to realize it.
A vaccine is never 100% effective, but …
Vaccines, while very effective, are never 100% effective. The reasons for vaccine failures are not yet fully understood. A vaccine can be partially defeated by poor immunity in the patient or a mutation in the virus. The fact remains that the latest studies suggest that vaccines retain significant efficacy against the Delta variant; if vaccines lose effectiveness with one dose, they show good levels with a full vaccination schedule; the Pfizer vaccine shows 88% success, close to what we see against other strains.
Even if this is damaging, it is therefore normal that a few rare cases pass through the cracks of the vaccination. And the more a population is vaccinated, the more the number of deaths will be important in this last. Concretely, if 100% of the population were to be vaccinated, 100% of deaths will be observed among those vaccinated, which does not mean – quite the contrary – that there would have been no death if the population had not been vaccinated.
The more people in society are vaccinated, the more of the deaths will be among vaccinated people.
Imagine a scenario where 95% is vaccinated, with a vaccine that is 90% effective, in a target group where IFR is 10% (80+).
(In reality vaccines are a lot more effective) pic.twitter.com/7yVE6pPCAy
— Tom Buytaert (@tbuytaer) June 22, 2021
Another small calculation to explain that we find more and more cases in the vaccinated. A simple rule of three is enough to understand the figure of 40% of new cases of contamination among the vaccinated population in Israel.
If 87% of the population is vaccinated and the vaccine is 90% effective, mechanically, a greater proportion of infected people will be found among those vaccinated, which will represent in absolute value a small number of cases.
“Despite significant vaccination coverage in Israel, 40% of new infections are from vaccinated people” -> Not “despite” bunch of dunces! This is the expected figure if 87% of the adult population is vaccinated and the vaccine is 90% effective. https://t.co/fGQ9B0GyXmpic.twitter.com/jGu8pEH2sV
— Sylvain Catherine (@sc_cath) June 28, 2021
In addition, the number of deaths among vaccinated people will be all the higher when it is the oldest populations or those with comorbidities, and therefore the most likely to die from natural causes, who are the most vaccinated. More than 94% of those over 70 have been vaccinated in the UK. We must therefore analyze the data with vigilance, a death after a vaccination does not mean that this is the cause.
Where the population is (very) little vaccinated
To be convinced of the effectiveness of vaccination against deaths, it suffices to look at the situation of countries which have low vaccination coverage rates such as Russia (11.8% of the fully vaccinated population) or Indonesia ( 4.9% of vaccinated). Against the background of a prevalence of the Delta variant, Russia (in green on the curve below) and Indonesia (in red) are currently experiencing the worst death rates since the start of the pandemic.
It is therefore wrong to analyze the pandemic on the basis of statistics alone of the proportions of contaminations and deaths between vaccinated and unvaccinated populations. According to an analysis published by Public Health England on June 28, the vaccination would have prevented between 6.4 and 6.7 million infections and between 26,000 and 28,000 deaths in England alone.
See also on The HuffPost: Relive the global race with this animated graphic