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Covid-19 patients in Ziv hospital in Israel
Photo: Atef Safadi / EPA
Vaccination world champion Israel - this term has become firmly established in people's minds.
And at the beginning of the year it was true: Hardly any other state implemented the vaccination campaign against Covid-19 as quickly and successfully as the country with nine million inhabitants.
By the end of March, 60 percent of the population in the country had been vaccinated at least once, and by the end of April the number of people vaccinated twice approached this value.
While Germany was still fighting the third virus wave in spring 2021, the people of Israel enjoyed extensive freedoms.
This gave hope, also for the further course of the virus spread in this country.
Now, however, more and more data is coming from the model country, which raises doubts as to the extent to which a high vaccination rate can stop the virus at all - and whether the vaccines are really that good.
However, caution should be exercised when interpreting these data.
Confusing numbers on vaccine effectiveness
The coronavirus is spreading strongly again in Israel (see graphic above).
The curve of people infected with Sars-CoV-2 has been pointing steeply upwards since the beginning of July and is approaching the previous peak values from the beginning of January.
The number of deaths has also increased since the beginning of August.
The government has tightened protective measures, people over 40 can pick up a third dose of vaccine.
The background to the measure is that data indicate that the protection against infection against the delta variant turns out to be worse and wears off over time.
Recently, data even seemed to indicate that the widely used vaccine from Biontech / Pfizer is weakening in its central task - protecting against serious illnesses: Around 60 percent of the people who were treated with Covid-19 in hospital on August 15 were Vaccinated, official data show.
However, they are misleading and once again distract from the real problem that is catching up with many countries in the pandemic: a vaccination rate that is too low.
In truth, good effectiveness is confirmed
"Many are confused by the results that more than half of the inpatients in Israel are vaccinated and think that means the vaccines are not working," writes Jeffrey Morris, professor of biostatistics at the University's Perelman School of Medicine of Pennsylvania, on Twitter.
His analysis shows that the data show exactly the opposite.
The rate of vaccinated among hospital patients, however, is influenced, among other things, by how many people in the population are already vaccinated and how old they are: the higher the vaccination rate, the greater the proportion of vaccinated among hospital patients - simply because there are more vaccinated than unvaccinated.
An example: If all people were vaccinated with a vaccine that reduced the risk of severe Covid-19 courses by 99 percent, there would still be very isolated people who would have to be hospitalized with the disease.
The proportion of vaccinated among the hospital patients would then be one hundred percent - despite the excellent effectiveness of the vaccine.
85 percent fewer hospital cases
To test how well vaccinated people in Israel are actually protected from hospitalization for Covid-19, Morris used the data to determine the effectiveness of the vaccines against courses with hospitalization.
To do this, he calculated the proportion of Covid-19 hospital cases among all those who were fully vaccinated and compared it with the proportion of hospital cases among those who were not vaccinated from the age of 12 (tweet above).
If the vaccination were ineffective, an approximately equal proportion of people in both groups would have to be treated in hospital for Covid-19.
In the case of those who were vaccinated, however, the proportion was 67.5 percent lower than in those who had not been vaccinated.
The vaccination reduces the risk of getting to hospital with Covid-19, according to the data by a good two thirds.
If Morris also took into account that the vaccination rates differ between people over and under 50 years of age, an effectiveness of 85 to 90 percent was shown.
If he broken down the age groups even more finely and included the fact that the risk of a severe Covid-19 course increases significantly with age, the effectiveness of 85 to 95 percent was even found, depending on the age group.
"This shows that the Biontech / Pfizer vaccine does very well against Delta in preventing serious illnesses," writes Morris in an extensive blog post.
The result is consistent with previous findings - which also come from Israel.
Vaccination breakthroughs almost never in healthy people
In a study published in a specialist magazine in July, experts evaluated data from 152 patients from 17 Israeli hospitals who were infected with Covid-19 despite having been fully vaccinated.
Only six of the 152 people were previously healthy, the rest had previous illnesses, such as a weakened immune system, which can affect the effectiveness of the vaccines (read more here).
The mean age of those affected was 71 years.
"So there were practically no major breakthroughs in Delta infections in people without significant previous illnesses in Israel," writes Morris.
A similar picture emerges in Germany: So far, a total of around 900 cases of people who had to be treated in hospital despite being fully vaccinated with Covid-19 - with around 49 million fully vaccinated people.
Most of them were older than 60 years.
The problem is the vaccination pick
Research has shown that antibody levels decrease over time after vaccination - especially in older people.
This can mean that vaccinated people become infected in rare cases and, in even rarer cases, become seriously ill.
"In my opinion, the data are significant enough to indicate a certain decrease in protection," writes Morris, referring to another analysis of infections in vaccinated people from Israel, which has not yet been published.
The extent is still unclear.
"It could be that the loss of protection is mainly limited to asymptomatic infections."
The problem in Israel and many other countries, including Germany, is currently less that the effectiveness of the vaccines against Delta is somewhat poorer and that it decreases over time with a view to infections, but rather that the overall vaccination rate is too low.
Israel is not doing as well when it comes to vaccination as it was at the beginning of the year.
The vaccination world champion is no longer one
After a quota of almost 60 percent had been fully vaccinated in the spring, the vaccination campaign stalled.
To date, only around 63 percent of the Israeli population is fully vaccinated.
Conversely, this means: almost 40 percent lack the complete vaccination protection that is important against the Delta variant.
That was enough to keep earlier variants of the virus in check even with comparatively few other countermeasures in spring and summer.
In order to curb the much more contagious Delta variant, however, a significantly higher proportion of those who have been vaccinated is necessary.
In purely mathematical terms, the number of immune people in society as a whole should be at least around 85 percent - preferably even higher (read more here).
In Germany, too, according to official information, only 58 percent of the total population are fully vaccinated.
Here, too, the number of cases increases again significantly (see graphic).
On the other hand, the world champions in vaccination include Malta, with a quota of fully vaccinated people of more than 90 percent, in Iceland almost 75 percent of the population have complete protection.
"It is mainly younger age groups that are affected by infections," writes the Robert Koch Institute (RKI) in its current weekly report for Germany.
The same applies to the growing number of hospital cases: “Most of the hospitalized cases were reported in the 35 to 59 age group, followed by the 15 to 34 age group.” In other words, in those age groups in which the vaccination rates are comparatively low.
