By Helen Petousis-Harris
Dr Helen Petousis-Harris is a vaccinologist and Associate Professor in the University of Auckland’s Faculty of Medical and Health Sciences
Helen Petousis-Harris looks at the potential complications of vaccinating older New Zealanders – and how we should prepare
Two weeks ago health authorities in Norway reported some concerns about deaths in frail elderly after receiving their Covid-19 vaccine. Are these deaths related to the vaccine? Probably not but here are the things to consider.
According to news reports up to 29 deaths have occurred shortly after vaccine administration and apparently 13 autopsies had some kind of indication that common vaccine side effects might have contributed. We do not have information on these and I can’t imagine how an autopsy would reveal that a person died of a fever, muscle aches, fatigue, or a headache (the common side effects).
The mass vaccination of the frailest in our population has always been concerning. This is not because of safety, but because of the high risk of coincidental adverse events, particularly among people frail enough to be living in aged care facilities.
Before we launch into this, keep in mind that in this age group the chances of dying from Covid-19 are around two in 10.
About deaths in older people
As we age, our risk of dying goes up exponentially (basically it skyrockets) and instead of the usual causes of death in people in their spritely 50s and 60s it is more likely related to the failure of body functions (basically we clap out). It is true that minor things can hasten a departure from the mortal world in a very frail older person.
How many deaths occur every day?
Of course, it is easy to calculate this for any country by dividing the annual deaths by days of the year. But this is pretty crude and if we only consider older folk there will be more deaths in the winter months as viruses such as flu wreak havoc.
In Norway, based on 2019 data, 13,150 people aged 80-89 and 10,057 aged over 90 years died. This is an average of 446 people per week and 64 a day in the very elderly. Other more robust estimates indicate this is higher.
In New Zealand, there were 17,583 people over 80 who died that year, an average of 338 per week and 48 per day.
So, every day nearly 50 very elderly people die in New Zealand and more than 60 in Norway. Norway has one of the highest life expectancies in the world at 82.3 years, in New Zealand it is 81.86 years, Australia 82.75, and the United States it is 78.54 years as a comparison.
Covid-19 vaccination in Norway
Norway began vaccinating on December 27 starting with residents in nursing homes and selected health care personnel. That is being followed by people age 85 years and above and further selected healthcare personnel. As of January 15 this year, around 42,000 doses had been administered.
Covid-19 vaccines and deaths – experience so far
If we just consider the Pfizer vaccine for now, during the Phase III trials deaths occurred in both vaccine and placebo recipients. All deaths were of the type that occur in the general population of the age groups at a similar rate.
A total of six (two vaccine, four placebo) of 43,448 enrolled participants (0.01 percent) died during the reporting period April 29, 2020 (first participant, first visit) to November 14, 2020 (cut-off date). Both vaccine recipients were more than 55 years of age; one experienced a cardiac arrest 62 days after the second vaccination and died three days later; the other died from arteriosclerosis three days after the first vaccination. Of the placebo recipients who died, one was from myocardial infarction, one was from haemorrhagic stroke and two were of unknown causes. Three of the four deaths occurred in the older group, more than 55 years of age.
Since administration of the Pfizer and Moderna vaccines began in the US, there have been 11 deaths. Almost all of these deaths were in people over 80 years of age and residing an aged care facility. None are considered related to receipt of vaccine. (See here for ongoing spontaneous reporting in the US.)
Vaccine reactions in older people
There is some concern in Norway that the reactogenicity (common reactions like fever) associated with the vaccines is too intense for the frail elderly. Is this possible? I generally doubt it, particularly as nausea and diarrhoea (reported to precipitate these deaths) are not side effects of the Pfizer vaccine.
Systemic events, those that affect the general body rather than the injection site, were generally increased in frequency and severity in younger age groups compared with older age groups. This is because these are related to an immune response and generally older people do not respond as intensely. The systemic events across all vaccines authorised at this stage are generally fatigue, headache, muscle pain, chills, joint pain, fever. In other words, flu-like symptoms that are fairly non-specific to many infections.
Vomiting and diarrhoea were reported at similar rates between vaccine and placebo groups. The median onset day for most events after either dose was day two or three, and they lasted a day or two. Among 65 to 85-year-olds in the Phase II studies systemic events were uncommon with only muscle pain reported as severe in a few people. There was no severe fever reported in this age group.
The point here is that the older the person, the less reactogenic the vaccines.
A few days ago, the WHO Global Advisory Committee on Vaccine Safety met to discuss this matter and concluded there was no evidence the vaccine precipitated these deaths, there were no unusual or unexpected reactions and the benefit-risk balance of the Pfizer vaccine remains favourable for the elderly.
The importance of background rates
It is vital that every country that has the capability should prepare baseline rates of possible adverse events, including deaths. This needs to be by age, gender, ethnicity, and so forth. Without this data it will be very difficult to determine if we are seeing more cases than we would expect without the vaccine. Most countries are not yet prepared with this data and would do well to get a wriggle on. There is a fair bit of work required to extract and analyse this kind of data so it is meaningful and useful.
Bureaucracy and funding barriers were overcome to develop vaccines at phenomenal speed but, in my opinion, this has not extended into the some of the issues of deployment. The reporting from Norway illustrates the absolute urgency to get this done. Is New Zealand ready yet? No.
A version of this article first appeared on Dr Petousis-Harris’s blog site, Diplomatic Immunity
Republished with permission.