What Israel tells us about boosters, waning immunity and Covid deaths

WHILE Scotland is still getting to grips with a vaccine passport system that requires users to have had two jags to enter nightclubs and large events, Israel has become the first country in the world to make booster shots a requirement under its own Covid pass scheme.

Since Sunday, eligibility for the country’s ‘Green Pass’ has been tightened to demand either proof of this third, top-up vaccination or recent recovery from the virus.

Without it, access to indoor spaces ranging from shops to restaurants and even some workplaces is off limits.

READ MORE: Almost 400 fully-vaccinated Scots died after Covid restrictions lifted

Israel was the first nation to launch Covid boosters in July, initially to the over-60s, and is so far the only country to have extended them to its entire population over the age of 12.

So what does their programme tell us about the impact of boosters, and how much can we be guided by their experience?

Like the UK, those prioritised for vaccination when the rollout first began in January were the most elderly and those with severe health conditions.

HeraldScotland: Israelis with the country's 'green pass' app which is required for entry into a wide range of public spaces, including bars and restaurantsIsraelis with the country’s ‘green pass’ app which is required for entry into a wide range of public spaces, including bars and restaurants

In contrast, Israel used only the Pfizer vaccine and spaced doses 21 days apart, meaning that by the time the Delta variant began spreading in there June the most vulnerable were already mostly five months on from their second dose.

By mid-August, breakthrough Covid infections were on the rise and roughly half the 600 patients hospitalised with severe disease were fully-vaccinated.

Further analysis determined that the majority of these individuals were over-60, had received their second dose at least five months previously, and also had chronic illnesses such as diabetes and heart disease.

READ MORE: Thousands more under-fives than normal receiving hospital and A&E treatment in Scotland

A report from Israel’s Heath Ministry at the time claimed that the effectiveness of the Pfizer vaccine against severe disease had dropped from 90 per cent to 55% among Israelis over 65 who had received their second jag in January.

One Israeli health official, speaking anonymously to the Financial Times this week, said it was “no longer a secret” that the vaccine is “not good after six to eight months”.

HeraldScotland: Covid deaths per 100,000 Israelis, over 60, by vaccination status (impulse - booster)Covid deaths per 100,000 Israelis, over 60, by vaccination status (impulse – booster)

Since rolling out its booster programme, it is clear that rates of infections and serious illness are substantially lower among over-60s given a third dose compared to those given only two doses.

During the final week in September, the daily death rate from Covid for the double-vaccinated elderly was 1.5 per 100,000 compared to the 0.13 per 100,000 figure for the triple-vaccinated.

HeraldScotland: Severe Covid per 100,000 Israelis, over 60, by vaccination status (impulse = booster)Severe Covid per 100,000 Israelis, over 60, by vaccination status (impulse = booster)

Hospitalisation rates similarly ranged from 28.5 cases of serious illness per 100,000 double-vaccinated Israelis over 60 to 2.6 per 100,000 for the triple-vaccinated.

Among the unvaccinated, the figure is 168.5 per 100,000.

A key difference in the UK is our decision to administer first and second doses 12 weeks apart – since reduced to a maximum of eight weeks.

While this decision was controversial and motivated by a goal to maximise vaccine coverage at a time when the Alpha (Kent) variant was exploding in the UK, evidence now indicates that this dosing delay actually triggered a stronger antibody response which may have cushioned us for longer against waning immunity.

On the other hand, the UK also relied on AstraZeneca to vaccinate the majority of over-40s and there are signs that its protection against infection (though not serious illness or death) dwindles faster compared to Pfizer – so much so that those given AZ may have a roughly 50-50 chance of infection now.

By the end of September, however, Covid rates among unvaccinated Scots remained twice as high compared to the fully vaccinated, and hospitalisation rates were nearly three times higher among unvaccinated over-60s than their fully-vaccinated peers: 46 per 100,000 compared to 17 per 100,000.


HeraldScotland: Weekly Covid deaths in Scotland from August 14 to September 24, by vaccination status, and showing age-standardised death rates per 100,000 by vaccination statusWeekly Covid deaths in Scotland from August 14 to September 24, by vaccination status, and showing age-standardised death rates per 100,000 by vaccination status

Inevitably, however, fully-vaccinated older Scots have made up a disproportionate share of the Covid deaths since restrictions were lifted in August.

In total, between August 14 and September 24, when virus rates soared, there were 380 deaths in fully vaccinated Scots compared to 96 in unvaccinated people.

To caveat, however: those most at risk from death – the very elderly – are nearly all fully-vaccinated (since ‘Beyond Zero’, 60% of Covid deaths in Scotland have been among adults aged 75 and over).

Moreover, 85% of all people in Scotland aged 16 and over are now fully vaccinated, and only 8.5% of people over 16 have had no vaccine at all.

Nonetheless, by the end of September the death rate from Covid still remained nearly four times higher among the unvaccinated than the fully vaccinated: 9.06 per 100,000 versus 2.33 per 100,000.

That is clear testament that the vaccines are working.

READ MORE: The ‘surprising’ fall in Scotland’s Covid cases – but will it last?

It is still possible that we were also seeing early signs of waning, however: of the 616 Covid deaths to date among fully-vaccinated Scots, 317 (51%) occurred in the space of just four weeks, from August 28.

Yet, the vast majority of over-80s – those most at risk – had been fully vaccinated since April.

The sheer scale of the outbreak may have been to blame, but it makes sense – based on the evidence from Israel – to proceed with boosters.

Some believe the UK should be going even faster, however.

Professor Neil Ferguson, whose Covid modelling triggered the March 2020 lockdown, has told MPs we should be “more aggressive” with the rollout, perhaps administering them four months rather than six months after the second dose, to maximise protection from Delta over winter.

The UK is “quite close to the limit of what the NHS can currently cope with”, said Prof Ferguson, but he stressed there are also huge uncertainties over how vaccination levels, waning immunity, weather and contact patterns will shape the epidemic over the coming weeks.

“It is harder to predict what will happen this year compared to last year when there was much less immunity in the population…but we could still see quite a substantial wave of transmission,” he added.

The Herald Scotland

The Herald Scotland

The Herald is a Scottish broadsheet newspaper founded in 1783. The Herald is the longest running national newspaper in the world and is the eighth oldest daily paper in the world. The title was simplified from The Glasgow Herald in 1992