Vaccines don’t work as well in old people. Some will still die despite protection from vaccines.

It is now looking like vaccines are less effective in people 50 or older, who make up almost all coronavirus deaths.  Vaccine effectiveness against death is more like 79% than 100%.  That aspect of vaccines will not live up to its hype.  Dying from COVID-19 will remain a problem.

I don’t know how this will impact the economy and how people will behave.  The coronavirus has been heavily politicized so it is hard to predict how the political winds will shift.  A safer prediction is to bet on COVID treatments doing well.  It looks like (A) most of humanity will get the virus and (B) old people are still at risk of dying.  This is the right environment for a massive COVID treatment market.

Natural immunity likely sets a ceiling on how well vaccines work

The theory is that vaccines and actual infections train our adaptive immune system, allowing it to better fight off a future SARS-CoV-2 infection.  The protection from vaccination and natural immunity depends on our adaptive immune system’s ability to keep its “memory”.

One problem is that the protection is not as good in the elderly as it is in younger population.  A Danish observational study analyzed reinfection rates among different age groups.  It found that the protection was significantly lower in elderly people 65 years or older- a half versus four-fifths.

  • 0–34 years old: 82·7% (CI 77·1–86·9)
  • 35-49 years old: 80·1% (CI 71·8–85·9%)
  • 50-64 years old: 81·3% (72·6–87·3)
  • >=65 years old: 47·1% (24·7–62·8)

Elderly people do not seem to develop immune “memory” as well as younger people.  This may or may not explain why vaccines are less effective in elderly people.

How effective are vaccines in old people?

At the moment, I haven’t seen health authorities post a useful analysis of their existing data.  I’m limited to analyzing the incomplete data that exists.

Comparing the difference between PHE technical briefing 17 and 18, there was a week-over-week increase of 66 deaths in vaccinated >=50 year olds versus 33 unvaccinated.  With 87.3% of that population fully vaccinated and 9.15% unvaccinated (calculated from the data here), the effectiveness against death is 79%.  Note that this data is for the mix of vaccines used in the UK (AstraZeneca, Pfizer) so switching to the best vaccine should yield better results.

This goes against the narrative that vaccines are more effective against death than being infected with SARS-CoV-2 (at least among older people).  This matters because almost all of the deaths occur in old people.  In the PHE data, 90% of the Delta variant deaths occurred in the >=50 year old group.  While vaccines are likely extremely effective against death in younger populations, they don’t seem to be as effective in the population that matters.  We will likely continue to see the phenomenon of vaccinated people making up a minority of the hospitalized population and a majority of deaths.  The good news is that vaccines significantly reduce hospitalizations, possibly allowing governments to lift social restrictions without breaking their hospital system.  Israel’s ministry of health is estimating that mRNA vaccines are 93% effective against hospitalizations.

Data exists

The clinical trials for vaccines have data on effectiveness in the elderly; I don’t know if that data has been made public.  While the AstraZeneca vaccine was studied in a cohort of ≥70 year olds, a trial result paper published in January this year only reports “selected secondary endpoints”.  The paper did not report these two secondary endpoints: “efficacy against severe and non-severe COVID-19” and death.

Does the vaccine work in really old people?  The paper does not say.  ¯\_(ツ)_/¯  Did the peer reviewers ask why the other endpoints were unreported?  Who knows.  ¯\_(ツ)_/¯

In any case, the truth is coming out.  Now that the Delta variant is hitting all demographics in the United Kingdom (instead of ripping through the education system), we’re seeing hospitalizations mainly among unvaccinated people and deaths mainly among vaccinated people.  Future variants will likely have more vaccine resistance so it will be hard to predict how vaccines will perform in the future.

I would be careful about extrapolating from the past because future variants will likely be resistant against vaccines and prior infections.  It’s hard to predict the deadliness and immune evasion of future variants.  The history of the IBV coronavirus suggests that a highly problematic variant (unusually transmissible and deadly) will emerge every once in a while.

Effectiveness against infection may be lower than we hoped

There’s something weird happening in Israel, where mRNA vaccine effectiveness has dropped to around 64% against infection (see here and here) compared to 95% reported earlier.  If you drill down into the age groups, it may seem like mRNA vaccines are effective in people 19 and younger and are pretty much completely ineffective (!!!) in people 20 years and older.

While I don’t fully know what’s going on, the best explanation is that people with natural immunity are massively overrepresented in the unvaccinated population (it is reasonable to expect natural immunity to offer better protection against variants than vaccination).  Removing everybody with a previous infection allowed Israel’s ministry of health to arrive at its 64% effectiveness number:

People confirmed as coronavirus patients before the beginning of the monitoring period are removed from the analysis, since their chances of repeated infection are different from those of the rest of the population who has yet to be infected for the first time.

Still, it’s not entirely clear why vaccine effectiveness has fallen to 64%.  Israel’s MOH believes that the Delta variant plays a role.  Maybe science will have an answer in a few years.

Israel’s unvaccinated demographic may be skewed because previously infected people enjoyed the same privileges as the double vaccinated.  The privileges were abolished when the Green Pass ended on June 1.  Because many other countries do not issue privileges to the previously infected, their unvaccinated populations may not be skewed so heavily towards natural immunity.  Other countries may see most confirmed infections occurring in the unvaccinated even though Israel sees roughly half of its infections in the vaccinated.

The politicization of the pandemic creates opportunity

I’ve been surprised at what a dumpster fire the pandemic has been.  A lot of people will not let go of their politics.

  • Among investment bank analysts, there is a bias towards believing that the pandemic will magically go away.  They tend to assume that remdesivir and vaccine profits will be short-lived.  They want institutional investors to get aboard the bullship so that these clients will generate profits for the bank’s underwriting department.
  • The “I believe in science” crowd doesn’t actually use Google Scholar or Sci Hub.  Instead, they rely on authorities for (non-)scientific information and ignore those authorities’ credibility issues.
  • The pro-censorship illiberal left has preferred narratives about their scientific experts being right.  Their tribe’s enemies and scapegoats are the ones spreading misinformation.  Their current obsession is that the coronavirus is now a ‘pandemic of the unvaccinated’.
  • The “mild flu” crowd downplays the coronavirus as a serious problem.  This is their way of fighting back against health policy being weaponized against them.  (There is also an anti-authority component because their tribe has been censored by the government and tech companies.  A small number of them have been fired, jailed, assaulted, or murdered for their political beliefs.)

Human beings are wired to be tribal and to fight each other.  However, it’s not healthy and leads some people to embrace janky narratives.  Cherished political beliefs are causing many investors to underappreciate stocks related to COVID vaccines and treatments.  Of course, we don’t actually need to play along with other people’s misinformation or politics.  We can simply make sensible decisions and find value that other people are overlooking.

Finally, I would like to talk about the uncomfortable direction that this blog has been taking.  The two pandemics happening at the moment, the culture wars and the coronavirus, have revealed ugly parts of humanity.  Humanity could have handled the coronavirus a lot better but politics got in the way.  The culture wars really did make gun demand skyrocket while the US is beginning to see people being jailed for their political beliefs.  I’m just trying to figure out what’s happening in the world even if the truth is unpleasant.  At some point we just have to accept the world for what it is.  When life gives you lemons, make lemonade.  I’ll be here talking about buying Moderna, puts on Disney and call options on Gilead Sciences.


*Disclosure:  Long MRNA, BNTX, GILD calls, and REGN calls.  I own puts on DIS.

3 thoughts on “Vaccines don’t work as well in old people. Some will still die despite protection from vaccines.

  1. Love the line “get aboard the bullship”! Laughed at that one.

    This has been my feeling since the beginning we are facing COVID forever. I wonder how politics will respond.

    I only invest in Canadian companies. One COVID stock to look at maybe is TSE:IFA. They are working on an anti-viral chemical for fabric. They are partnered with a company to make medical scrubs treated with this chemical. If COVID stays in the headlines then it could be a good seller.

  2. Great article. Deaths are way down in Israel and UK on a per infection basis. Death rate is only 1/12 on per infection basis. The pandemic is over it is now a very contagious flu that is not that deadly, especially if you are under 65. Our public health officials are garbage.

  3. Pingback: Long COVID, which is sometimes caused by vaccines, can be effectively treated – Glenn Chan's Random Notes on Investing

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