This guest article on the impact of the Covid-19 vaccine is by Lars Kroijer, a regular contributor to Monevator.
When the history of the pandemic is written, the 16 January 2021 may stand out as the first day there was tangible evidence that the vaccines were starting to have an impact.
With that day came the first seeds of hope that the terror, misery, and mayhem of this crisis will finally end.
Covid and its consequences
The tragic death count from Covid-19 looms largest in our minds, of course.
More than two million globally have died so far.
Beyond that – and Monevator is a primarily investing blog – Covid-19 has crippled the global economy.
Some sectors have come to a standstill. Investors are naturally reluctant to invest in businesses directly impacted by the virus. One year into the pandemic, and new variants of the virus, the uncertain number of people infected, and the varying speed of the vaccine rollout leaves huge uncertainties.
In this article I will argue that while there remains many moving parts and huge unknowns going forward, we already have early signs that the vaccine is working to beat back this virus. With this knowledge, we – and the markets – can then try to predict how vaccine programs will reduce deaths and hospitalizations in different countries.
This is good news. Not only because of the hope of a brighter future ahead and the saving of countless lives. But also because if we can introduce a bit more predictability into all this uncertainty, then investors and employers may dare to back and support sectors that they would otherwise avoid.
Finally we could return to business as usual.
Progress of Covid-19 vaccinations in Israel
On 16 January, Israel announced that its 7-day trailing deaths to 15 January had fallen from 5.25 to 5.18 per million people.
That’s about a 1% decrease.
On 17 January it was announced that the same number for 16 January was again 5.18. No change from the day prior.
January 18 & 19 had small upticks in deaths.
That was followed by another ‘smallish’ decline on January 20.
This path in itself may seem unremarkable. But stay with me.
Israel began vaccinating people the week before Christmas (Hanukkah there). By 24/25 December around 2-3% of its population had been vaccinated.
As in most countries, those most at risk of getting seriously ill or dying were vaccinated first. This means the percentage of the vulnerable population that has been vaccinated will be disproportionately higher.
Since then, Israel has continued to lead the world in vaccinations. The chart below illustrates the fraction of the Israeli population that has so far received the 1st jab of the vaccine.
Share of Israeli population (LHS) vaccinated to-date
How effectively does the vaccine reduce death?
The different Covid-19 vaccines approved so far vary in their efficacy at preventing infection.
Expected success rates range up to 95% – that comes after two jabs, around three weeks apart – but science suggests the vaccines offer protection of approximately 50% from around 10-14 days of receiving the first jab, and rising thereafter.
This suggests the 2-3% of the population who had been vaccinated in Israel by Christmas would have roughly 50% protection by around 3/4 January.
After that initial protection level of approximately 50%, the resistance grows in the following weeks to provide around 90% protection.
So early vaccine recipients may only have been 50% protected in early January, but protection would continue to grow after that.
Israel has been using the Pfizer vaccine. Below is a table of how we could expect it to protect a recipient in the days following an initial jab.
Escalating protection for recipient from first Pfizer jab:
It is possible that vaccine efficacy will prove to be lower than expected. It’s very early days, but recently a medical expert from the Israeli government suggested just that.
However others have pushed back against some emerging doubts about Israel’s vaccination campaign.
As the efficacy numbers of the various vaccines become more concrete, we can re-run the model with updated numbers. For now though we’ll stick with what the efficacy studies have suggested so far.
By combining the number of people vaccinated with the time taken for the first jab to have an impact, we can get a sense of when vaccination began protecting some of the Israeli population:
The time taken between someone becoming infected with the virus before they unfortunately succumb to it varies a great deal. Factors include an individual’s resilience and the strength of the local hospital system (Israel’s is first rate). On average, 9-14 days seems to be generally agreed in the scientific community.
Of the 2-3% of Israeli’s population who had been vaccinated and had 50% (and growing) protection by early January, some will have gone on to contract Covid-19. A proportion will have died from it, but others survived because of that jab they received around Christmas.
This is where the tiny decrease in deaths I noted is potentially very significant.
Saved by the vaccine
From 1 to 16 January, Covid-19 cases recorded in Israel increased from 550 to around 950 per million people. (Not dissimilar to the UK).
That is a greater than 70% increase in the period, or 3.5% per day.
All else equal, you’d expect the 10 to 14-day post-infection death rate to eventually go up by a similar amount. A proportion of those infected in early January would succumb to the virus. The 7-day deaths per million in Israel would be expected to rise about 30%.
Yet in realty it declined, by 1%, in the seven days to 15 January.
Does this matter? Yes, hugely so
Israel’s trailing 7-day increase in deaths has not kept up with the 10 to 14-day prior increase in cases. Over the past couple of days, for the first time it has declined.
Something seems to be working and that is very good news indeed.
The next chart is of 7-day trailing deaths as a fraction of 7-day trailing cases, from ten days prior. While there is noise in the data, the trend is clearly downward. We presume this shows the vaccine having an impact.
Trailing deaths as a fraction of trailing Covid-19 cases in Israel
While Israel had ‘only’ vaccinated 2-3% of its population by Christmas, those vaccinated were in large part the most vulnerable.
We assume the likelihood of death from Covid-19 in this group is roughly 10-20 times that of the general population. We would expect deaths in this cohort to decline by around 20-40% once the vaccine has taken effect.
It is impossible to be more precise in estimating how deaths are curbed without knowing exactly who was vaccinated.
For instance, some vaccinated early will have been frontline workers. They are well-deserving, but not as likely to die from Covid as the very old or vulnerable. My 10-20 times figure assumes a mix of the approximately 25-30 times more vulnerable, and frontline workers.
It is impossible for me to be more precise with these numbers, considering the many moving parts and noise in the data.
But let’s assume my assumptions above are correct. Instead of 7-day deaths going from 100 to 130 in the trendline, it should remain at 100 deaths.
That is roughly what happened.
Looking forward to falling deaths
As vaccination continues, we will be able to partially check our maths.
We can already estimate how much likelier a vaccinated cohort is to die from Covid compared to the general population.
The first people to receive the vaccine were mostly very vulnerable. The next cohort is still vulnerable but a little less so. And so on down from there.
Below is a table with some assumptions on vulnerability to succumb to Covid by vaccination cohort.
You can see how vaccinating the more vulnerable first steadily increases the percentage protected who otherwise might have died from the virus:
For example, we assume the 4th percentile cohort of the Israeli population that is vaccinated – so number 300,000 to 400,000 of Israel’s approximately ten million people – are 7.2 times more likely to die from Covid than the average person.
If Israel gets to the point where it has vaccinated 80% of the population, the last people it vaccinates will have a ‘death likely’ multiplier of less than 1. As the younger and healthier, they are far less likely to die from a Covid infection than the average of the population.
We cannot be too precise. New variations of the virus could evade the vaccine or diminish its efficiency, leaving early protection lower than 50%. Or perhaps the maximum efficacy of first jab could prove to be below 90%.
What’s more, the seemingly positive change in the past week in Israel could even be a short-term data aberration. Or perhaps Israeli hospital treatment or capacity has improved. (That’s unlikely though in light of the large increase in cases. You would actually expect this to lead to a disproportionate increase in deaths due to hospitals getting overwhelmed).
It could even be that reporting methodology of cases, vaccines, or deaths have somehow changed over the period.
But if the trendline has been broken and the recent decline in mortality in Israel is because of the vaccine, then it’s great news.
Deaths should go down very fast
Israel has now vaccinated an incredibly impressive 25% of its population.
Other countries like the UAE, the UK, and US are at around 19%, 6%, and 4% respectively.
Since these countries are largely vaccinating the most vulnerable people first, we should start to see declines in the death rates in the coming weeks here, too.
This is hugely positive. It saves many people and their friends and families the obvious horror of unnecessary death.
Even among those vaccinated who still get infected but do not die, we’d expect milder symptoms. This lessens the pressure on the hospital system. That should mean better outcomes for those that do get sick from Covid. Hospitals will be less likely to run out of ICU beds, ventilators and so on. (Remember deaths are a trailing indicator, not a leading one).
Also, reduced pressure on hospitals should free up capacity to treat non-Covid illnesses that have been put on hold. This should indirectly benefit many non-Covid patients (a positive externality that is not a part of this analysis).
Estimating a falling death rate from vaccination
Using the above logic, we could also approximate the number of deaths in a population from any delay in vaccinating. Especially in countries with high infection rates and low vaccination rates.
Some countries seem hopelessly behind in vaccinating their population. I don’t know how these delays are not a massive political scandal. It is not about being left or right on the political spectrum, but rather government competency. Some seem to be failing miserably and many elderly will die unnecessarily from Covid as a result.
Israel has set the standard. The logic developed below could estimate the number of additional deaths in a country that does not vaccinate as quickly and efficiently.
To check our assumptions against reality, we can compare what we would expect to be the impact of the vaccines on the trendline of percentage deaths of people who got infected 10-days prior with what actually happened in Israel once it began vaccinating.
In the week before Israel started to vaccinate, 0.9% of the people who contracted Covid ten days prior passed away. This percentage was fairly consistent with the period leading up to the start of the program.
Once Israel began to vaccinate, we would expect a 10-day delay before the vaccines started to offer protection. We’d then begin to see the death rate fall.
Refer back to the table above on deaths by cohort. Applying its assumptions to the fraction of Israeli’s vaccinated, we would expect to reduce deaths as follows:
We can also compare the expected decline in death rates to the actual decline in 10-day trailing death rates:
The death rate lines roughly correlate in the days after we expect the vaccines to start providing protection. That suggests our model is somewhat correct in predicting the fall in the number of deaths.
The obvious conclusion it that the falling death rate is a result of the widespread vaccination program in Israel. These are however very early days, and there could easily be noise in the data in the weeks ahead.
But as the line of the expected future death rate in Israel suggests, we can expect the number of deaths to continue down in that country as protection mounts.
Will vaccination also reduce Covid cases?
I have read some medical experts say that those vaccinated are less likely to be carriers who can infect others. But there is not a clear consensus.
If the vaccinated were less likely to be carriers it would be great news. It would lower the number of cases, as there’d be fewer spreaders in society.
What’s happened so far? We’d hope for case numbers in countries like Israel and the UAE to decline if the vaccinated were less infectious. But so far their infected counts have continued to rise.
This in itself doesn’t prove that vaccinated people can be carriers. It could be because there are more infectious variants of the disease spreading it faster. Or perhaps some people are starting to take post-vaccine life for granted, and so behaving more recklessly.
Time will tell. Hopefully we will soon start to see cases as well as deaths decline in the most vaccinated countries.
Also, as of around 20 January only around 15% of Israelis had received a vaccine in time for the effects to be felt.
Most of the population has not been vaccinated. Thus any potential reduction in infectiousness has yet to apply to them.
Again, the reason we expect the death rate to decline disproportionately is because those vaccinated early were the likeliest to die.
Closing the curtain on Covid-19 as a crisis
The creators and producers of the vaccines and our health workers are the heroes of our time. Help is on its way, and soon.
The daily Covid news is bleak in the UK and US. But don’t lose hope now that the end is – hopefully – in sight.
In the UK, a body called the Covid-19 Actuaries Response Group has produced a similar sort of analysis to mine above. It estimates falling deaths as follows, taken from The Spectator:
It’s looking good. But the alternative to these (relatively) optimistic projections is almost too much to bear.
If such analysis is flawed and deaths do not decline, then something is not working. The future would be far grimmer. Let’s hope not.
Predicting a brighter life after Covid
What should investors make of all this?
The analysis above suggests that vaccinating even a small percentage of the population that are very vulnerable has a disproportional impact on the number of deaths and severe non-death cases. That will result in reduced pressure on the hospital systems.
It also means we can begin to predict with some accuracy what will happen going forward.
This greater predictability should help alleviate the fear factor in the economy. More companies and investors will believe things are getting better. As Covid deaths fall and pressure on hospitals eases, governments will look to reopen their economies.
Hopefully this will put more pressure on slow-moving governments to keep up with the likes of Israel, too. That could save the unnecessary deaths of thousands of the most vulnerable.
We all know Covid cases initially go up exponentially. My hope is that by dramatically reducing deaths and serious illness on the most vulnerable, the vaccine will quickly reduce Covid’s impact on society. Perhaps even in a shorter time frame than is currently anticipated.