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.

Samoa’s devastating measles epidemic – why and how bad? - Diplomatic Immunity

Nov 28, 2019

Samoa are experiencing a devastating measles epidemic. It is possible that 2-3% of the population will ultimately be infected by the time it is over. Hopefully the mass immunisation campaign currently under way can mitigate some of this, for many it is too late. (Updated 3 Dec 2019)(Updated 7 Feb 2020) The first question many people ask is “why?” The general answer is simple. Samoa has long term low immunisation coverage. The tables below illustrate this. The top table is the first dose of MMR vaccine and the next is the second dose. These figures are some of the lowest in the world. Estimates of coverage of MMR dose 1 in Samoa. Unicef and WHO Estimates of Immunisation Coverage 2018 Revision This low immunisation coverage has left Samoa extremely vulnerable to measles – a lit match to dry tinder … Read More

Whooping cough vaccine works well despite its imperfections - Diplomatic Immunity

Nov 07, 2019

Pertussis (whooping cough) is a conundrum. It is a disease that was described hundreds of years ago and the bacteria that causes it (Bordetella pertussis) isolated in 1906. We have had vaccines for about 80 years but this disease is defiant in the face of human immunity. I wanted to address some misconceptions about pertussis vaccines. Seven key points in case you cant be bothered with the detail. Pertussis is horrible Pertussis has killed heaps of New Zealanders Pertussis is not always obvious – you can’s always tell who has it The vaccines work well The vaccines are not perfect and both symptomatic and asymptomatic people can carry and transmit the infection. The current pertussis vaccines are incredibly safe, even if you are pregnant Best group to be in is the vaccinated group Pertussis is horrible The disease is a … Read More

Why are vaccinated people getting measles? - Diplomatic Immunity

Sep 04, 2019

Here is a very quick and over simplified explanation about why some of the cases of measles are fully vaccinated (epidemiologists look away!). The vaccine is not 100% protective. One dose is around 92% and two doses around 98%. Generally, things look like this pie chart, assuming the vaccine is potent and the patients relatively healthy. Most cases occur in the unvaccinated with a few in the vaccinated.   A common pitfall is to look at the number of cases by vaccine status, for example when I looked today at the recent measles report it shows that among 10-19-year-olds 17 cases are fully vaccinated and 96 are not vaccinated. A natural inclination is to go OMG! the vaccine is only 85% protective. The problem with doing this is that most people are vaccinated, you need the denominator. The … Read More

Why is there a rip-roaring measles outbreak in NZ? - Diplomatic Immunity

Aug 21, 2019

As with many countries around the world, NZ is experiencing the worst measles outbreak in over 20 years. Welcome back to the dark ages. This was predictable,  entirely preventable, and the government were warned. If this outbreak is not stamped out by March next year NZ will lose its hard-earned measles elimination status. There are four reasons for this – in my opinion, and one solution. Reason #1. Historical poor uptake of MMR vaccine. This issue mainly affects people in their teens through to around 30 years of age. When measles vaccines were introduced the incidence of the disease declined. This resulted in two things happening. One; fewer people caught measles so never became immune that way. Two, many people did not receive a vaccine against measles therefore did not become immune that way. There is still a large pool … Read More

Authentic resistance or authentic distortion? - Diplomatic Immunity

Aug 05, 2019

Authentic resistance appears to be a two woman army advocating that the body’s natural immune system is all that is required to keep healthy. They assert that parents must make an informed decision about vaccines based on information from the medical literature. On the latter point we agree. The Resistance is holding seminars around the country on “Informed consent and natural immunity.” The seminars appear to be based on twisting the intent of informed consent, misinformation about vaccines, and their personal concept of natural immunity. Let’s just unpack a few of those topics below. Distortion 1. Informed consent. Informed consent is the process by which the individual is appropriately informed in an environment and manner that is meaningful and they can agree without coercion. The person must understand the that they have a choice, what they are being offered, what … Read More

How many nails does it take to secure the MMR/Autism coffin? - Diplomatic Immunity

Mar 05, 2019

Twenty-one years ago the most significant piece of medical piffle was published in a prestigious journal under fraudulent pretences. The now long since retracted article proposed that the MMR vaccine caused autism based of the purported claims of 8 parents. Yes eight (8). Same number of legs on an octopus. Same number of babies delivered by Octomom in one sitting. This wanton deception held the world to ransom, ably assisted by an all too eager unquestioning mass media. There is a mountain of evidence High-quality research from multiple quarters quickly confirmed there was absolutely no association between the vaccine and autism, the nails went in the coffin one after another in fairly quick succession with a 2014 meta-analysis (that pools together several studies into an even bigger study) concluding no association. Read More

Killer meningococcal disease outbreak – some context - Diplomatic Immunity

Nov 30, 2018

Is there a killer epidemic of meningococcal disease in NZ? In 2018, as of November, 10 people in NZ died of meningococcal disease and six of these deaths were caused by Group W (as opposed to A, B, C, Y, and Z). Historically most deaths in NZ have been caused by Group B so this is a change. Group W has a higher fatality rate (18.2%) than B and C (7.1%). I am starting with a simple graph that shows all the meningococcal disease cases notified in NZ since 1989. It kind of speaks for itself. NZ Meningococcal disease notifications by year, 1989-2018* (Source ESR Meningococcal Report Nov 2018) NZ Meningococcal disease notifications by year, 1989-2018* (Source: ESR Meningococcal Disease Report. Nov 2018) I think the answer is no, but there does appear a small upswing. Perhaps by the … Read More

Meningococcal rare but deadly, yes there are vaccines - Diplomatic Immunity

Nov 07, 2018

Meningococcal disease is scary, really scary. Like many of our most insidious diseases meningococcal disease often presents like a flu, and most people who present with a flu-like illness have… a flu like illness. How much meningococcal disease is in NZ? In 2014 NZ had 45 cases and in 2017 there were 112. So far this year there have been 96 cases. The risk is about 2-3 per 100,000 people. In contrast, for flu, this season the rate of visits to the GP for a flu-like illness was over 400 per 100,000, most are under five of age. Note my general extrapolations from this week’s data but you get the point. However health professionals always have to consider the possibility that the person has something other than flu. Read More

How safe is the MMR vaccine? - Diplomatic Immunity

Jul 13, 2018

In the tiny Pacific Nation of Samoa, on Friday 6 July 2018, two babies died shortly after receiving MMR vaccine. How could this happen? Lots of discussion is going around about this tragedy, and even more questions. Here are some responses to the things I have been asked this week summarised under the headings below. About MMR vaccines How safe are MMR vaccines? The risks of measles mumps and rubella People who should forego the MMR vaccine How can vaccination with MMR go wrong? What happened in Samoa? About MMR vaccines MMR vaccines were originally developed in the 1970s to protect against measles, mumps, and rubella, in one convenient jab. However, there is a long history of the development and use of measles-containing these vaccines that extends back to the 1960s. Read More

Move over ASIA now we have HANS - Diplomatic Immunity

May 12, 2018

There appears competition to claim discovery of HPV syndromes. Another in a list of attempts at assassinating the safety of HPV vaccine has been retracted this week. This time from Nature Scientific Reports. Grant Jacobs has provided a commentary on another just a day earlier. That one is a real doozer, an author with a fake name as well! I admit this one had flown under my radar when it was published in 2016, so I have just had a read of it now. How it passed the most cursury review by any expert I cant imagine because the background section alone rang alarm bells. You see, it was devoid of science and cited instead psuedoscience to support the study premise (that HPV vaccine causes autoimmunity). No where did the article mention the scientific safety data drawn … Read More