Israel’s omicron surge shows we must keep immunity topped up

Israel is one of the vaccine stars of the pandemic. It rolled out its initial jabs with great speed this time last year amid the deadly alpha wave. It saw off delta in the summer by pioneering booster shots. And, as omicron hit, it made fourth doses available to medics and the elderly.

But late last week, charts started to do the rounds on social media showing Israel’s death rate apparently soaring.

“Israel is among the most highly vaccinated and boosted countries on the planet. [Yet] they are breaking daily records for Covid deaths”, tweeted Aaron Kheriaty, a psychiatry professor recently fired by the University of California for refusing to abide by its vaccine mandate. “Our public health establishment needs to explain this… because people are dying.”

We are all jittery having suffered the strictures of SARS-CoV-2 for two years now, so the ex-professor’s tweet and others like it grabbed attention. It plays to anti-vaxxers and the biases of those – like Dr Kheriaty – who continue to erroneously insist “natural immunity is our only way out of this pandemic”.

Things have not been helped by a data glitch. On Friday the Israeli ministry of health issued an alert warning that the data being displayed on global dashboards was giving a “false picture of reality” regarding the daily number of deaths in Israel.

Yet, even once this is accounted for, deaths in Israel have climbed sharply over the past month. Using the Ministry of Health’s own data, deaths per million currently stand at about five a day in Israel, up from next to nothing at the start of January and approaching the record rate of 6.98 per million the country recorded at the peak of the alpha wave.

So what is happening? Why should a country that is so well vaccinated still be suffering like this? According to experts, there are a number of answers – the first being that although Israel’s vaccination rate once sat at the top of all vaccine charts, it has gradually slipped to a middling position.

But more importantly, perhaps, is the fact that vaccination rates among the vulnerable are not as good as they might be. While in the UK nearly all the most vulnerable are fully vaccinated, in Israel 10 per cent or more of the over-60s remain unprotected.

Another issue is that, like here, the omicron wave has been dramatic. “Israel has basically let omicron rip, eschewing almost all the layers of protections we had, including PCR testing and quarantine for contacts of the infected,” local expert Barak Raveh told The Sunday Telegraph yesterday.

Raveh, an assistant professor of biological modelling at the Hebrew University of Jerusalem, said the number of those unvaccinated and the omnipotence of omicron only provided a “partial explanation” – the waning of the effects of initial vaccinations also helped explain why, of 822 deaths recorded since the start of the year, only 293 were unvaccinated.

“I do not mean to suggest the vaccine is ineffective at all – it is still 90 per cent effective if we normalise by population size – but what I think happened is some attrition in the effect of August’s booster shots”, said Dr Raveh.

“Israel was the first to provide them back in August and their effect may have waned considerably. It was believed at first that this affected only infection rates, but apparently, it also caused more cases of severe disease.”

The uptake of the fourth vaccine dose to combat this waning has also been poor, he pointed out. “Israel was the first country to authorise a fourth dose back in early January to both medical staff and the elderly, but only half of those eligible took it, in part because early reports about its effectiveness were mixed.”

In fact, a fourth dose turns out to be incredibly effective. Recent real-world data from Israel show it leads to a 4.3-fold decrease in severe disease in the over-60s, compared with a third dose given more than four months earlier. “Giving the fourth dose to individuals who were at risk of developing severe disease has been instrumental in limiting the burden on hospitals in Israel during the fast and wide-spreading omicron surge”, said the study’s authors.

So what is the lesson of Israel’s omicron wave for the UK? And what might it tell us about the pandemic going forward? One clear message must be to keep vaccine-induced immunity topped up. For the moment at least, it is vaccines that are keeping us safe.

“I think as a country, we may have been a bit too relaxed in terms of letting omicron cases soar under the conception that it is a relatively mild disease,” said Dr Raveh. “Even if the disease is milder [than the alpha or delta variants], we ended up with crowded hospitals amid an intense flu season and suffered a larger than expected number of severe cases and deaths.”

For the moment, we must keep our guard up.