COVID vaccinations and dementia

By Matthew Croucher. Published on 29/10/2021

What’s the story about the dementia and the COVID vaccine in New Zealand – is it safe? Dr Matthew Croucher discusses the evidence.

What are the risks of the vaccine for people living with dementia?

The vaccine that was chosen by the New Zealand government and approved by Medsafe for use is a COVID-19 mRNA vaccine made by the drug company Pfizer in partnership with the vaccine specialist company BioNTech.  It has been closely monitored in New Zealand as well as around the world and many millions of people have now received it.  The Centre for Adverse Reactions Monitoring (CARM) based in Dunedin publishes monthly updates on the data that has been collected about this vaccine in our country.  Over 5 million doses have been given to New Zealanders so far and the percentage of people in the age groups most likely to be living with dementia who have been double-vaccinated is high. CARM’s most recent reports show several things relevant to the question of whether the COVID vaccine is safe for people with dementia.

  • The overall number of adverse events that have been reported in New Zealand that might be due to vaccination with the Pfizer/BioNTech agent drops substantially the older the person who received the vaccine was.  However, as expected, the number of serious health outcomes that could potentially be due to vaccination rises with age.  This is because older people are more vulnerable to serious adverse health events no matter what the cause.
  •  Many of these events will have just occurred by chance will not be related to the vaccine, for example, someone who was at high risk of having a heart attack who then has one a week after getting the vaccine.   Some adverse events will be due to the vaccine, so all serious events are investigated further by the person’s doctor and CARM.  There is currently only one signal that is relevant to dementia that is being monitored more closely because it is considered that it is possible that there might be a causal relationship, but the actual number of reports is still too low to be certain.  This is for the risk of stroke in the 21 days after vaccination, occurring in anyone (not simply people with dementia).  The numbers of actual strokes after vaccinations in New Zealand is very low despite the number of vaccine doses being very high.  There is no signal at this stage for excess adverse events of any kind for people with dementia.
  • The NZ death rates in the 21 days following either dose 1 or dose 2 of the vaccine are lower than (or occasionally equal to) those predicted, for all ages including the oldest old.

Psychiatrists of Old Age and Geriatricians routinely monitor the international scientific and clinical literature.  No signal has emerged overseas that there are particular dementia harms relating to the Pfizer/BioNTech vaccine.  This does not mean that there are never any such outcomes, only that there are no consistent or frequent negative outcomes for people with dementia.

What are the risks of not giving the vaccine to people living with dementia?
On the other hand, the effects of COVID-19 on people with dementia is becoming clearer with every passing month.  It is absolutely the case that the COVID-19 virus is able is able to and does enter brain cells directly – it is not just a disease of the lungs but of many parts of the body.

  • In New Zealand, most of our COVID deaths have been in people living with dementia.  Around the world, having dementia is associated with a substantial increase in risk of death from COVID (about 5x the risk compared with people without dementia) and it is estimated that about one third of all people that have died from COVID around the world had a dementia.  Everyone focusses on frail elderly with respiratory conditions being at high risk of dying from COVID, and they are very vulnerable, but people with dementia are right up there in terms of risk of death.  
  • People with dementia also probably have a higher risk of being sent to hospital if they have COVID, although that is a less reliable statistic because in some of the countries studied, people with dementia were less likely to be admitted to hospital because overwhelmed health systems restricted hospital access to people who were most likely to benefit from Intensive Care (this excludes many people with moderate or severe dementia).
  • COVID-19 is increasingly being suspected to be a cause of increased incidence of dementia in people who were at risk but did not yet have it.  It is still too early to be sure about this, but a longer-term increase in the number of people who develop dementia is one of the possibilities dementia experts are worried about internationally.
  • "Long COVID", that is, persisting symptoms for weeks or months after the acute illness is over, is also increasingly recognised to have a range of long-term brain consequences including cognitive impairment.  “Long COVID” is much more common than previously thought - it is not a rare outcome.
  • Most of these signals come from studies concerning people who were cognitively normal prior to contracting COVID.  We expect that people with pre-existing dementia will be worse affected, but the studies have not yet been done that can show us exactly what is happening.
  • COVID-19 increases the risk of stroke somewhere between 3-7 times.  This is a much higher increase than the possibility that the Pfizer/BioNTech vaccine may be associated with a small increased risk of stroke and unlike the possible vaccine risk which is still under investigation, the COVID risk is believed to be definite.
  • •COVID-19 causes lockdowns to save lives and prevent the non-lethal complications of COVID-19, but they are generally thought to be harmful for people living with dementia, although there are some exceptions.  Community and individual vaccination is the key the opens the door to ending prolonged lockdowns in this country.

Therefore, dementia experts in this country don't simply recommend that people living with dementia receive the Pfizer/BioNTech vaccination in New Zealand, they warn that unvaccinated people with dementia are likely to be our first and most severely affected citizens when the Delta variant runs through the community, which it is now beginning to do.  It will not be "OK to leave them behind" because people with dementia are among our most vulnerable citizens to this plague.  It's a terrible position for them to be in and my colleagues and I are very concerned for this group of our Elders, who are often forgotten.

What about deaths from COVID?

We’re all going to die, and for some of us death is not far off and is not our enemy, it is our friend.  That doesn’t mean we hasten it, but we won’t fear it and fight it.

This is true for people in the last chapters of their lives with dementia.

So what does that mean in terms of the COVID vaccine?

Dying with COVID is not great, primarily because it is difficult for other people to do all the things that make a person’s dying gentle, dignified and loving.  When a person is dying with COVID, there are restrictions about who can be with them and those people have to wear protective equipment.  This means it is very hard to surround people with love and care.  We can’t hold their hand without wearing gloves, and they cannot see us smile because of our masks.  The best of what palliative care can offer is difficult or impossible when people need to be in isolation to protect everyone else.  That’s why the very last time you want to die is during a pandemic.

Some people die with COVID but not everyone dies from COVID.  Dying from COVID is different for everyone, but having a high fever and being in respiratory distress is not pleasant and these are common.  Palliative care medication can help with this, but not always.  The deaths of people with dementia from COVID in Christchurch last year were not particularly bad in terms of the medical side but they were uniformly poor in terms of being able to be supported to have a ‘good death’ with family.

What are the risks to others?

Another factor to bear in mind is that vaccination is not just a treatment to protect us as individuals, although it does, it is a treatment that protects the community.  If COVID gets into an environment that a person lives in, be that our private residence or a Rest Home, we need to have as many barriers as possible to protect everyone else that lives and works there from what would happen if COVID jumps from person to person.  What would a Rest Home do if most of its staff were positive?  Where would the new staff come from?  What would happen to their partners and children and their lives while they all have to isolate?  What about the other older people living in the Rest Home?  Are they all comfortable about taking on the risk of getting very ill and dying?  When we vaccinate, we are vaccinating for other New Zealanders not just for ourselves.

That’s why vaccination is recommended for all people with dementia no matter what the severity.  It is not solely or even primarily to preserve life, but to make it possible for people to continue to have good deaths as well as to protect our communities.

Matthew Croucher 
Dr Matthew Croucher is the chair of the New Zealand Dementia Foundation. Matthew is a senior psychiatrist of old age and academic working for the Canterbury District Health Board.

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