For much of the Covid-19 pandemic, the world has looked at Israel and seen signs of things to come. Its vaccination campaign was one of the first to get started, enabling the country to end its lockdown even as other states tightened theirs. In a pattern that is likely to become apparent elsewhere in coming months, however, Israel, despite 80 per cent of its residents being double jabbed, is recording higher daily infection numbers than at any time since February. New restrictions on social life may be introduced unless the spike in infections can be brought under control.
The most likely explanation for the new surge, the Israeli government has concluded, is waning immunity among those who are fully vaccinated combined with the higher transmissibility of the Delta variant. A faster-than-anticipated fading of the protective effects from the Pfizer/BioNTech vaccine, which was the main product in use in Israel, has resulted in a higher risk to those who were vaccinated first, including the oldest and medically vulnerable. The phenomenon is reflected in an growing number of international studies. Last week, researchers at the University of Oxford found that 90 days after a second shot of the Pfizer or AstraZeneca vaccine, their efficacy in preventing infections had slipped to 75 per cent and 61 per cent respectively. That was down from 85 per cent and 68 per cent, respectively, two weeks after the second dose. The trend underlines that herd immunity is likely to be an illusory goal.
Israel began administering third Pfizer shots last month in an attempt to drive down the infection rate. Early signs indicate that it is having a positive effect. Ireland, like the United States and many European countries, is planning to begin its own booster programme next month, starting with older people and those who have weakened immune systems. The idea has not won universal backing, however. The World Health Organisation has quite reasonably noted that it "makes a mockery of vaccine equity" for rich countries to be giving out third doses while African states still struggle to get supplies.