Helen Petousis Harris

Dr Helen Petousis-Harris blogs about vaccines and vaccination. Her background is predominantly biological sciences, and she did her PhD in Vaccinology, specifically around vaccine reactions. She worked at the Immunisation Advisory Centre at the University of Auckland between 1998 and 2018 where she has developed a passion for all things vaccine. Currently Helen has an appointment as an associate professor in the Department of General Practice and Primary Health Care and her teaching is largely around vaccination. Her research focuses on a number of aspects of vaccines and vaccination but in particular vaccine effectiveness and vaccine safety. She was previously the chair of the World Health Organization Global Advisory Committee on Vaccine Safety (GACVS). Of course all opinions in this blog are her own. Disclosures: Helen has led a number of industry funded studies. These have all been investigator conceived and led. She does not receive honorarium from industry personally. She has received industry support to attend some conferences and has contributed to Expert Advisory meetings for GSK, Merck, and Pfizer. Helen is a member of the Covid vaccine Science and Technical Advisory Group to MBIE and the MoH and the Covid Immunisation Implementation Advisory groups to the MoH.

Correcting propaganda containing 8 false claims about COVID-19 vaccines - Diplomatic Immunity

Apr 28, 2021

This is a short blog addressing a list of falsehoods being posted widely across Aotearoa New Zealand. The flyer (posted at the end) claims ‘8 important covid vaccine facts you probably haven’t heard’. Actually, these are 8 of the most common myths about Covid-19 vaccines. Some have been around so long they probably qualify as zombie myths. The ‘golden rules‘ of propaganda are used in the flyer – uses intense emotions, creates a dichotomy between “good” and “bad”, avoids data and rational discussion. #1 The COVID-19 vaccines that NZ has pre-purchase agreements for appear very safe. There have been some very rare blood-clotting events detected following administration of the viral-vector vaccines (Astra-Zeneca and Janssen) and these are being intensively investigated. Claims that suggest there are an alarming rate of deaths and serious injury caused by the … Read More

The Pfizer COVID-19 vaccine is way beyond experimental - Diplomatic Immunity

Apr 25, 2021

An experiment is a procedure carried out to test a hypothesis. We have determined through experiment, with extremely high precision, that the Pfizer COVID-19 works very well and is very safe. The initial experiments were successful, moving on… However, there are some misconceptions flying around that abuse this concept and I thought they needed addressing with some interpretation and facts. Hope this is helpful and clears up a few confusions. The most widely used COVID-19 vaccines are no longer ‘experimental’. One could argue that there are still experimental studies in play, for all of these vaccines, but then it is also the case for pretty much every vaccine I can think of. My group have been studying a vaccine that has been in wide use since the 1940s, among others. We never let up. Once a vaccine has been authorised … Read More

COVID vaccines and blood clots – what is this about? - Diplomatic Immunity

Apr 15, 2021

I will update this post as new information comes to hand What has happened? Recently the vaccine safety watch dogs in Europe noted reports of unusual types of blood clots in people vaccinated with the AstraZeneca (AZ) COVID-19 vaccine. This prompted investigations across many countries to ascertain what, why, and how. Also, in the last couple of days, the U.S. has reported unusual types of blood clots in people vaccinated with the Janssen/Johnson & Johnson COVID-19 vaccine. Observations so far suggest that in younger AZ vaccinees, primarily women, there might be an unusual type of blood disorder that involves both low platelets (that can lead to bleeding) and blood clotting at the same time (thrombocytopenia and thrombosis). This disorder is appearing a week or two after vaccine administration and has been given several names so far … Read More

COVID vaccine safety – adverse events vs. adverse reactions - Diplomatic Immunity

Apr 07, 2021

As we roll out the COVID-19 vaccine across NZ there will inevitably be people who experience adverse events after getting their jab. Here are some super important things to keep in mind about adverse events following immunisation. I will update this blog as we go along, latest 16 April. Terminology – words matter Any event that is undesirable and follows administration of a vaccine is called an adverse event following immunisation (AEFI). This is the term applied regardless of whether the vaccine was the cause of the event. An adverse reaction is, by definition, an adverse event that has been caused by the vaccine. This is a subgroup of all adverse events.   Some adverse reactions are obvious – a super sore arm or rash where the injection was given are pretty clearly reactions to the … Read More

COVID-19 vaccines and community immunity (transmission) - Diplomatic Immunity

Jan 22, 2021

Updated, 4 Feb 2021 to reflect new data on the AstraZeneca vaccine.  Q: Will the COVID-19 vaccines prevent the transmission of the coronavirus and bring about community immunity (aka herd immunity)? A: Jury not in yet but vaccines do not have to be perfect to thwart the spread of infection. While vaccines  induce protection against illness, they do not always stop actual infection, so you can be perfectly well but carry a deadly virus or bacteria and spread it to others. Typhoid Mary springs to mind, where in the nineteenth century Mary Mallon unknowingly infected at least 53 people with typhoid fever while perfectly well herself. Vaccines such as the HPV and measles vaccines prevent infection all together so vaccinated people do not transmit the infection, while other vaccines such as pertussis (whooping cough) prevent disease … Read More

The frail elderly and COVID vaccines – should we be concerned? - Unsorted

Jan 16, 2021

(updated 18 Jan to reflect new information) Health authorities in Norway are reporting some concerns about deaths in frail elderly after receiving their COVID-19 vaccine. Is this causally related to the vaccine? Probably not but here are the things to consider. According to the news there have been 23 29 deaths in Norway 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 cases and I can’t imagine how an autopsy would reveal that a person died of a fever, muscle aches, fatigue, or a head ache (the common side effects). The more recent report states: Most people have experienced the expected side effects of the vaccine, such as nausea and vomiting, fever, local reactions at the … Read More

How good is the AstraZeneca vaccine looking? Look at the data, not news headlines - Diplomatic Immunity

Jan 15, 2021

Happy New Year! No, experts are not concerned that “…one of New Zealand’s COVID-19 vaccines will fail to protect the country” Here is why. But first I wish to issue an expletive about this journalism (First in Australia and then in NZ). It exhibits utter failure to actually truly consult the experts, other than a passing token quote. I call false journalistic balance. Grump out of the way, here is the story. A virology society in Australia issued a public statement about the AstraZeneca COVID-19 vaccine (AZ). They compared it to the Pfizer RNA vaccine and said it would not be good enough to achieve ‘herd immunity’ and Australia should halt deployment of it. They stated that the efficacy of the AstraZeneca vaccine was 62% and that the efficacy of the Pfizer vaccine was 95%. Oh boy … Read More

Pressing the pause button after an adverse event happens to a vaccine trial participant - Diplomatic Immunity

Sep 09, 2020

Today AstraZeneca pushed the pause button on its late-stage trials of a COVID-19 vaccine. A clinical trial participant has experienced a serious health event and an investigation is underway to determine the cause. What does it mean? A cautious approach – trials can halt to assess safety data With over 200 COVID-19 vaccines now under development we are going to start seeing participants in the clinical trials have heath events. These events may or may not be completely unrelated to the vaccine under study. When you have what will ultimately be hundreds of thousands of people under observation in clinical trials, some will get sick, especially when you start recruiting older people into these studies. When this happens sometimes the trial will need to be halted while the event is investigated, and a lot of questions … Read More

COVID-19 vaccines and human cell lines - Diplomatic Immunity

Aug 26, 2020

When science meets ethics and morality. Vaccines are biological products and will have be exposed to various organic and inorganic products during their manufacture, depending on vaccine type. This includes exposure to human cells. Research that informs vaccine development will certainly have relied on such products along the way. Some people have faith, morality or safety-based concerns about the use products sourced from animals, such as gelatin. Animal products used during the manufacturing process, if still present in the finished vaccine, are only present in minute (trace) amounts and are not ‘vaccine ingredients’ per se. If you have ever had a medical intervention of pretty much any kind you will probably have ultimately benefited from the use of animal cells or product. But what about human cells? No COVID-19 vaccines are not made from aborted fetuses! Also (other than the … Read More

That Russian COVID-19 vaccine – not for us thanks - Diplomatic Immunity

Aug 12, 2020

Updated 3 Feb 2021 to reflect peer reviewed data on Sputnik. Note this blog was originally published 21 Aug – a month before the developers of this vaccine began recruiting into a phase III trial and a month before the early Phase I-II data was published so I absolutely stand by my critique. As of today Phase III data has been published and the trial appropriately registered. The first data includes over 20,000 randomised adults (3:1 so more received the vaccine) over 18-years. The efficacy against COVID disease was estimated to be 91.6% after two doses and 73.1% after one dose. This vaccine appears effective and there were no safety concerns identified. Pity they failed to be transparent and appeared to be cutting corners early on.  Russia are deploying … Read More