Has Vaccine Effectiveness Against Death Been Overestimated?

The ‘stylized facts’ concerning vaccine effectiveness against Covid are as follows. First, the vaccines confer strong protection against infection, which peaks about one month after the second dose. However, this protection then wanes over the following five or six months to as low as 20% (or even lower).

Second, the vaccines also confer strong protection against serious illness and death, and this protection wanes much more slowly. Hence, six months vaccination, the vaccinated still have substantial protection against death.

While these stylized facts are approximately right, there’s reason to believe that vaccine effectiveness against death has been overestimated. Note: by ‘overestimated’ I simply mean that effectiveness may be somewhat lower than is claimed, not that effectiveness is zero (or even close to zero).

The reason effectiveness against death may have been overestimated was highlighted in a recent study by the U.S. CDC. Using data on a large cohort of Americans, Stanley Xu and colleagues calculated non-Covid death rates (adjusted for age and sex) among vaccinated and unvaccinated persons.

Their findings are shown in the figure below (taken from the Economist). Notice that, on both charts, the light blue bar is much higher than the other two bars, indicating that non-Covid death rates were substantially higher among the unvaccinated.

The researchers interpreted their results as evidence of vaccine safety. (If the vaccines were very unsafe, you’d expect a lot more non-Covid deaths in the vaccine groups.) However, there’s another implication, which the researchers also acknowledge: people who get vaccinated tend to be healthier and/or more risk-averse than those who don’t.

How do we explain this ‘healthy vaccinee’ effect? There are at least two possibilities. First, some people may be too frail to get vaccinated, due to old age or underlying health conditions. Second, some people may just be inherently healthier/more risk-averse, and as a result may be more likely to get vaccinated and less likely to die of other causes.

The CDC researchers actually attempted to control for the healthy vaccinee effect by selecting unvaccinated persons from among those who’d had at least one flu shot in the last two years. The fact that they still observed a difference in death rates suggests the true effect may be even larger.

While the CDC’s results might be good news from the perspective of vaccine safety, they’re bad news from the perspective of vaccine effectiveness.

Suppose you do a study, and find that the Covid death rate is ten times higher among unvaccinated people than among vaccinated people. That difference could be due to the vaccines. But it could also be due to the fact that vaccinated people are less likely to die for any reason.   

Observational studies of vaccine effectiveness do attempt to control for the healthy vaccinee effect, for example by including some measure of health/frailty as another variable in the analysis. However, these kinds of measures may not capture all the relevant differences between vaccinated and unvaccinated people.

Israelis Without Booster Jab Could Be Stripped of Vaccine Passports

More than a million Israelis could be stripped of their vaccine passports because they’ve not received a booster jab, meaning they will be barred from indoor venues (unless they have proof of having recently recovered from Covid). Thousands have been pushed to get their third dose after the Government updated the definition of ‘full immunity’. The Financial Times has the story.

“I believe the fourth wave is coming to an end,” the Health Ministry’s Director General Nachman Ash said in a radio speech, attributing the success to the booster campaign. “We are on our way, but I say this with caution.”

Simultaneously, the Health Ministry released data saying common side effects like fatigue or pain in the arm were all measurably lower after the third jab than after the first or the second.

Israel, which was the first nation to use the Pfizer vaccine, used boosters to avert an August lockdown as the vaccine’s efficacy waned and infections soared, especially among the elderly, who started filling up Israeli hospitals with severe illness.

Faced with the possibility that its hospitals could be overrun, Israel offered to give third shots, first to the immune-compromised, then to the elderly, and eventually, to the entire adult population before either Pfizer or other international health bodies like the U.S. Food & Drug Administration (FDA) had fully studied the subject.

Prime minister Naftali Bennett outlined the virtues of booster shots, first to U.S. President Joe Biden in late August, then at the U.N. General Assembly two weeks ago. Faced with the choice of another lockdown or doubling down on vaccines, “we chose the latter – we pioneer the booster shot,” Bennett told world leaders. “Two months later, I can report that it works.”

So far, Israel is the outlier in offering boosters to the entirety of its population over 12, not just the clinically vulnerable. After fierce debate, and strong suggestions from the White House that the U.S. would soon follow suit, the FDA limited Pfizer booster shots to people over 65, those at severe risk and to those in jobs where they are likely to be exposed to a lot of virus in their daily interactions.

In all cases, their second shots had to be at least six months ago, as in France, which was the first European country to start administering booster jabs to its over 65 years old last month.

Worth reading in full.

Vaccines Failing Against Serious Disease, Data From Israel Suggests

There follows a guest post by the academic economist who contributes regularly to the Daily Sceptic, who has looked in more detail at data from vaccine pioneer Israel and found indications that the vaccines are not protecting against serious disease and death as well as is generally thought.

Israel remains the gold standard when it comes to macro data for vaccine efficacy. As many know, it started its vaccine program early and its roll-out was remarkably quick. Over 60% of the population is fully vaccinated, while rates of vaccination in vulnerable groups are upwards of 90%.

It is no secret that despite these numbers, Israel is experiencing another wave of the virus. This can be seen clearly in the positive test rate data (data from Our World in Data).

We have all come to accept that the vaccines have little impact on infection – this even though we were once told it was 95% effective against infection. But no matter – be sure to throw that down the memory hole. The latest ‘mandatory science opinion’ is that the vaccine prevents cases from evolving into severe cases that require hospitalisations and, eventually, death.

Given the data in Israel we can now test this hypothesis.

Let’s start with hospitalisations. If the vaccine is preventing hospitalisations, then the rate of hospitalisations per positive test rate should have fallen dramatically relative to history. Has it? Here is the data.

No, Minister, Vaccine Passports Are Not Necessary to End the Pandemic

Vaccines Minister Nadhim Zahawi has insisted to MPs in the Commons that vaccine passports are necessary to end the pandemic. The evidence, however, suggests otherwise.

While the U.K. has seen a spike in reported ‘cases’ in recent days, much of it is driven by the increase in testing as schools have returned. The positive rate, by contrast, shows a gentle decline.

There’s no sign here of vaccine passports being needed to prevent unmanageable spread.

What about elsewhere? Israel is a highly vaccinated country which got in there early with vaccines, so that upwards of 55% of the population has been double vaccinated since early April, and it has made extensive use of vaccine passports.

India, by contrast, is a low vaccination country which only recently broke through 10% double vaccinated.

How are they faring? Israel is currently experiencing a big surge in Delta infections, at a time when over 62% of the population is double vaccinated.

Are the Vaccines Declining in Effectiveness Against Serious Disease?

Reported positive ‘cases’ have been increasing slightly in the U.K. recently, though the trend appears to be flattening.

United Kingdom

Interestingly, the rise has been concentrated outside England, which has been declining in the last week or so.


Scotland has seen the most striking rise, linked it appears to the return of children to school on August 18th.


The Scottish surge in ‘cases’ is linked to a surge in testing – it seems that parents have not been testing their children over the summer, and the requirement to do so for school has picked up a load of hidden infections (presumably these children and their families have not been isolating over the summer either).

Israeli Study Finds that Natural Immunity Protects Much Better Against Infection than Pfizer Vaccine

Since the start of the global vaccine roll-out, it’s become increasingly clear that – although the vaccines provide strong protection against severe disease – they provide only limited protection against infection.

Israel and Iceland, two of the most vaccinated countries in the world, have recently seen major outbreaks of COVID-19. Both countries had fully vaccinated 60% of the population by July 1st. Yet by early August, Iceland had posted its largest daily total for the number of new infections since the pandemic began, and case numbers in Israel were soaring.

However, the question of whether vaccines are superior to natural immunity in terms of protection against infection has remained open. According to a Guardian article titled “Common myths about Covid – debunked”, which was written by a member of Independent SAGE, natural immunity is “not as good as the protection you get from being vaccinated”.

Yet a new paper suggests the reverse may be true: natural immunity is stronger and longer-lasting than vaccine-induced immunity.

Sivan Gazit and colleagues analysed a large sample of anonymised patient records from Israel. Their sample included two key groups: fully vaccinated people who’d never tested positive; and unvaccinated people who had tested positive.

In addition to matching these two groups for size, and average demographic characteristics, they controlled for ‘immune activation time’. This was done by limiting the sample to people who’d been vaccinated or infected between January 1st and February 28th, 2021.

Patients’ Covid outcomes (subsequent infection, hospitalisation or death) were measured during a follow-up period between June 1st and August 14th.

What did the researchers find? Of the 257 cases that were detected in the follow-up period, 93% occurred in the vaccinated group, and only 7% occurred in the previously infected group. And of nine hospitalisations, eight occurred in the vaccinated group, compared to just one in the previously infected group.

These results indicate that natural immunity confers substantially more protection against infection than vaccine-induced immunity. They also suggest that natural immunity confers more protection against hospitalisation, although one should be cautious here, as there were only nine hospitalisations in total.

The researchers point out that their results may only apply to the Delta variant, and to the Pfizer vaccine, and that they couldn’t control for all relevant differences between the two groups. Nonetheless, their paper provides the strongest evidence to date that natural immunity beats vaccine-induced immunity when it comes to infection.

Francious Balloux of UCL, a self-described “militant corona-centrist”, said the paper “is a bit of a bombshell”. Though he added that “essentially every adult who hasn’t been infected yet greatly benefits from being vaccinated”.

Gazit and colleagues’ findings still need to be replicated. But if they prove to be robust, then government priorities may shift substantially going forward. The case for vaccinating healthy young people will be even weaker. And the case for donating surplus vaccines to poor countries will be that much stronger.

Vaccine Passports Are Back in Israel

Vaccine passports are back in Israel, little more than 11 weeks after Jerusalem-based writer Arieh Kovler wrote in the Spectator: “The scaremongers who said that vaccine certificates would be some lasting form of social control were wrong.” From today, Israelis over the age of three must show proof of vaccination against Covid or of a negative test to be allowed into indoor public spaces, except for malls and stores. Mask mandates are also back, including for large outdoor gatherings. Haaretz has the story.

Children between the ages of three and 12 will be entitled to receive free rapid antigen swab tests. Those aged 12 and up who are not vaccinated will have to pay for their own tests. Around 220 testing stations will operate throughout the country to carry out these tests, and more will be added according to demand, the Health Ministry said. Results from the rapid antigen swab tests are available in 15 minutes, and a negative result grants a Green Pass valid for 24 hours.

The requirement to present proof of immunity will be applied in most sectors of the economy and public and private institutions, including swimming pools, gyms, academic institutions, all cultural and sporting events, conferences and exhibitions, museums, libraries, restaurants, and hotels. 

However, the Green Pass will not apply to summer school programs, so that parents will not have to test their children every day as a condition of participation.

Starting Wednesday, the number of participants at events will be limited to 1,000 people in enclosed spaces and 5,000 at outdoor events without assigned seating. At events in private homes, where proof of immunity won’t be required, the attendance limit will be set at 50 in enclosed spaces and at 100 in open ones. There will be no limit on crowd sizes at events with assigned seating, but these events will also require proof of immunity.

The renewed requirement for vaccine passport checks comes amid fears over the Delta Covid variant, reports the Guardian.

After its launch in December, Israel’s widely praised vaccination drive helped to drastically bring down infections. But that trend has since reversed, driven by the spread of the more contagious Delta variant of the virus, with restrictions that were lifted in June reimposed since July. …

About one million Israelis have not been vaccinated even though they are eligible.

According to the Health Ministry, more than 8,700 people tested positive for Covid on Tuesday, the highest number for a single day since January.

The Haaretz report is worth reading in full.

Pfizer Vaccine Effectiveness Drops to 64% in Israel

As infections have surged in Israel in the last few weeks, the Israeli Government reports that the effectiveness of the Pfizer vaccine against infection has dropped to 64% from 94% the previous month. However, its effectiveness against serious disease is holding up. The Telegraph has more.

The vaccine had a 64% efficacy rate from early June until early July, the latest figures show, down from 94% a month earlier. The decrease coincides with a period in which the government reversed coronavirus restrictions and the delta variant spread through the country.

But the vaccine is still conferring strong protection against severe symptoms of the virus, with hospitalisation rates remaining low. The ministry’s data shows the vaccine’s efficacy in preventing hospitalisation was 93% from June 6th to July 3rd, compared to a 98% rate in the previous period.

On Monday, Israel reported the highest rate of new infections since the start of its most recent outbreaks, with the ministry recording 343 new cases over the past 24 hours.

Over half (55%) of the new infections are in fully vaccinated people, according to recent data. Since the country has fully vaccinated about 60% of the population, this suggests the vaccine is not protecting from infection very much at all (less even than the new stated efficacy figure of 64%). This is particularly so given that most of the infections are likely to be in socially and economically active younger people (like they are in the U.K.) who have lower vaccination rates, so that the vaccinated may even be suffering disproportionately more infections than the unvaccinated (the data is currently unavailable to confirm this).

The pattern of outbreaks in highly vaccinated countries such as Bahrain, Seychelles, Maldives and Chile and the fact that the vaccines don’t produce mucosal IgA antibodies has suggested for a while that their effectiveness against infection may have been exaggerated in studies. The idea that the IgG antibodies they produce in the blood should protect against progression to serious illness makes more sense and it is reassuring to see this data holding up.

The Israeli Government is now discussing the need for a third booster shot, and Pfizer CEO Albert Bourla has said people will “likely” need a third dose within 12 months of getting “fully vaccinated”. The Government may also consider limiting gathering sizes and reintroducing the controversial “Green Pass” vaccine apartheid system.

However, if a highly vaccinated country like Israel cannot return to normal without constant threat of new restrictions you have to wonder if anyone can. At some point leaders will need to accept that they have done all they can to guard the vulnerable against serious illness and death and remember that there is more to life than avoiding COVID-19.

Stop Press: The Centers for Disease Control and Prevention (CDC) is now investigating the death of a 13 year-old American boy who died a few days after receiving his second dose of the Pfizer Covid vaccine.

Lockdown Restrictions to Come to an End In Israel from June – But They Could Return Further Down the Road

The success of Israel’s Covid vaccine rollout means that the country’s lockdown restrictions – vaccine passports included – will be revoked from the beginning of June. But Health Minister Yuli Edelstein says restrictions could return if Covid cases surge again. The sudden U-turn on vaccine passports suggests that, as could be the case in Britain, certification was introduced at venues merely to ‘nudge’ younger people into taking the vaccine. Reuters has the story.

With the majority of the population having received the Pfizer-BioNTech vaccine, and about 92% of those 50 and older inoculated or recovered, Israel has been gradually reopening its economy after three lockdowns.

The country reported just 12 new virus cases on Saturday, down from a daily peak of more than 10,000 in January.

Curbs on higher-risk activities and limits on how many people can gather in a specific area remain, with a Government-issued “Green Pass” that indicates immunity post-vaccination or recovery from Covid allowing greater freedom.

Health Minister Yuli Edelstein said on Sunday that he will not be extending the arrangement, meaning the restrictions and the Green Pass system will be revoked from the start of June.

“The economy and the citizens of Israel will get extra room to breathe,” he said, but also warned that they could be reimposed should the situation take a turn.

Rules on mask-wearing inside and incoming travel will also be reviewed by the Health Ministry in the coming months.

Worth reading in full.

Case Numbers Do Not Always Decline After Lockdowns

Lockdown proponents often argue that, although case numbers sometimes decline in the absence of a lockdown (as in SwedenSouth DakotaFlorida), case numbers always decline in the presence of one. Once you put a lockdown in place, they claim, the curve reaches its peak and the epidemic starts to retreat.

There are certainly many countries where a decline in case numbers has coincided with the imposition of a lockdown. However, this doesn’t necessarily mean that one caused the other. 

As the researcher Philippe Lemoine has argued, people start changing their behaviour voluntarily when they see deaths and hospitalisations rising. The government, meanwhile, feels an increasing need to “do something”, and the subsequent imposition of a lockdown happens to coincide with the peak of the infection curve.

Consistent with this account, there are several countries where a lockdown was imposed, but case numbers did not immediately decline; or if they did decline, they rose again while the lockdown was still in place. These examples constitute evidence against the claim that lockdowns have a substantial effect on the epidemic’s trajectory. Here I will present six. 

It’s important to note that some countries went into lockdown all at once, whereas others built up restrictions gradually over several weeks. This raises the question of exactly how to define a lockdown. For the purpose of this analysis, I will rely on the Oxford Blavatnik School’s COVID-19 Government Response Tracker. 

The dataset includes several measures of government restrictions. Each one is accompanied by a “flag” indicating whether the relevant restriction was applied to specific regions or the entire country. I will define the start of a lockdown as the first day on which there were mandatory workplace closures and a mandatory stay-at-home order in place for the entire country.

The first example is Israel, which went into lockdown on December 27th, but did not see the peak of its infection curve until January 17th.

The second example is Lebanon, which went into lockdown on November 14th, but did not see the peak of the curve until January 16th.

The third example is Slovakia, which went into lockdown on October 22nd, but did not see the peak of the curve until January 6th.

The fourth example is Slovenia, which went into lockdown on October 20th, but did not see the peak of the curve until January 10th.

The fifth example is Peru, which went into lockdown on March 16th, but did not see the peak of the curve until June 2nd.

The sixth example is Venezuela, which went into lockdown on September 28th, but did not see the peak of the curve until April 6th.

Note that, in every case, the lockdown measures were in place until after the peak of the curve. The fact that cases did not immediately decline, or proceeded to rise again (as in Venezuela), cannot therefore be blamed on the lifting of lockdown measures. 

The evidence presented here is consistent with the many empirical studies finding that lockdowns do not substantially reduce deaths from COVID-19.