Reports of about 30 deaths among elderly people in the nursing home who received the Pfizer vaccine have made international headlines.
As the Australian Therapeutic Goods Administration (TGA) is expected to approve the vaccine soon, starting next month, this development could be a cause for concern over the safety of the vaccine.
But there are some reasons why it should not be.
What we know
We have not seen this problem in any other countries rolling out the Pfizer vaccine.
Norway has so far reported that about 45,000 people across the country have been vaccinated against COVID-19. Their vaccination program has mostly focused on residents in nursing homes.
In other countries, there may be more focus on health workers in the front line in the first place. Therefore, if there is a link between deaths in the elderly and this vaccine, it may not be clear yet.
It also depends on supervision. Norway can have a particularly fast surveillance and reporting system that can effectively detect all those vaccinated and can quickly report any adverse outcomes.
We anticipate that soon oversight reporting from other countries with an active vaccination program is expected, which will increase the critical data to create a more accurate picture of vaccine safety in different populations.
The reports from Norway will make other countries sensitive to keep a close eye on vaccine recipients, especially those who are older and vulnerable in nursing homes. We may see further reports on this from other countries in the coming weeks.
But we may not either. We have limited information on these matters in Norway. The people who died allegedly were elderly and very debilitated. Many people in the very old days had significant underlying health conditions, and they could possibly be nearing the end of their lives, independent of the vaccine.
Although they are being investigated, it is important to note that the deaths were not definitively linked to complications of the vaccine. Meanwhile, Australian experts have called for calm.
Vaccines and the elderly
In the recent history of vaccines, we have not seen any trends showing mortality in the elderly after vaccination. For example, there is no evidence that the annual flu vaccine is associated with deaths in older people – or people of any age.
However, it is important to note that we are comparing apples and oranges when compared to the flu shot or another vaccine and the Pfizer vaccine for COVID-19.
The Pfizer vaccine is based on mRNA technology, which is completely new in a human vaccine. This technology introduces some of the genetic material of the SARS-CoV-2 virus in the form of messenger RNA (mRNA). It instructs your cells to become part of the virus that stimulates an immune response that inhibits infection and protects against disease.
All vaccines are designed to generate an immune response – albeit in different ways – to prepare our bodies to fight the virus if and when we encounter it.
Creating an immune response leads to inflammation in the body. Some people have no side effects from a vaccine, but the inflammation can manifest in different ways in different people and between different vaccines. It may mean a reaction at the injection site, or feeling tired, or unwell.
The deaths in Norway were reportedly associated with fever, nausea and diarrhea, which would be tolerated for the vast majority of people, although it was at the severe end of the spectrum of vaccine side effects.
How different people will respond to the mRNA is what we are now beginning to understand. It is possible that this vaccine will have serious consequences in older, vulnerable people where the initial inflammatory response may be overwhelming.
But it is still too early to draw conclusions.
Side effects show that a vaccine elicits an immune response
Vaccinations must produce an immune response in order to work, and side effects are a by-product of our bodies that produce an immune response.
Although the deaths are sad, they should not be a cause for concern. It actually tells us that the vaccine stimulates an immune response. For most people, this reaction will be completely tolerant and lead to the development of an immune memory that protects you from severe COVID-19.
The biggest challenge for any vaccine is to generate enough immune response so that you can be protected against the disease in question, but not too much that you experience serious adverse effects. Where this line exists in the sand, the different people will differ, but the oldest and most brittle vaccine recipients are most likely to have serious, potentially life-threatening reactions.
So for those who are more susceptible, we might want to be a little more careful. Upon approval of the Pfizer vaccine, the TGA may consider recommending this particular vaccine to people who are very elderly and debilitated, especially those who have other conditions and may be nearing the end of their lives.
Ideally, the vaccine should be considered on a case-by-case basis for this group, carefully weighing the risks and benefits in each situation based on the best available data. 
Nathan Bartlett, Associate Professor, School of Biomedical Sciences and Pharmacy, University of Newcastle.
This article was published from The Conversation under a Creative Commons license. Read the original article.