Pfizer’s corona vaccine only protects about 70 percent against infection with the extra contagious ‘delta variant’ of the virus. Israeli scientists have established that.
Fortunately, the vaccine still provides excellent protection against severe illness and hospitalization. Nevertheless, Israel wants, among other things, to reintroduce the just abolished ‘green’ corona passes – the Israeli version of the CovidSafe app – to cut off the virus.
The new figures, released by experts at the Hebrew University on Sunday evening confirm that the delta variant is a lot more “elusive” for vaccines than previous variants. Before the emergence of the variant, the vaccine was still 94.3 percent effective against infection in Israel. However, in June, it was only 64 percent. In Israel, almost all infections are of the delta type.
Don’t panic, responds the Dutch virologist Marion Koopmans (Erasmus MC) when asked: the vaccine still protects against disease. But the figures do underline that the delta variant can move around quietly more easily than the earlier variants. “Certainly in a population that is still only partially protected. That makes the vaccination campaign even more of a race against time,” says Koopmans.
All in all, the successful Pfizer vaccine would be 60 to 80 percent effective against infection with the virus, the Israeli scientists calculate. That is in line with British findings: against mild illness from the delta variant, the Pfizer vaccine protects 78 to 93 percent, compared to more than 90 percent. Moreover, the vaccine still protects about as well as before against hospitalization, according to the British.
The figures for the AstraZeneca vaccine and for vaccines after only one shot are less sunny. For example, AstraZeneca works against infection with the new variant for 67 percent (74 percent). However, after one injection of AstraZeneca, people are only protected against the delta variant by about 30 percent (previously: 49 percent), and after one dose of Pfizer, the protection is 36 percent, instead of the previous 47 percent.
Many numbers indicate: the virus wriggles and wriggles and does its best to break through the vaccines by adjusting its spines a little each time. Nevertheless, the vaccines are still very good: one shot of Pfizer protects 94 percent against hospitalization.
In Israel, people are now looking for a new counter-move. For example, they are considering trying to administer a dose of Moderna vaccine as a third shot. The emerging insight in immunology is that the different brands of vaccines can, when added together, provide somewhat broader protection.