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 is chair of the World Health Organization Global Advisory Committee on Vaccine Safety (GACVS). Of course all opinions in this blog are her own. This is a science blog, dissent is welcome if justified and respectful. Trolling and personal insults are not and will be trashed. 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.

Smashing down the barriers: Where are we at with COVID vaccines? - Diplomatic Immunity

Mar 31, 2020

In the absence of a vaccine or a cure for a deadly disease, staying home in your bubble is what you do, the concept is not new.  To the best of my knowledge last time we did this in NZ was for polio, in the years before a vaccine came along. So, what can we expect for COVID-19? This blog is a little lengthy but hopefully summarises the vaccine scene with respect to COVID-19 under these headings: Traditional vaccine approaches are not a great fast track option All vaccines need testing in people before wider use Breaking the first barrier to getting a vaccine through human testing Traditional vaccine technology New technologies – breaking down the barriers to getting a vaccine FAST. Some key technologies for fast vaccine development COVID-19 vaccines in the front running COVID-19 vaccines – … Read More

Beating the evolving COVID-19 pandemic – unprecedented human collaboration in discovery and innovation - Diplomatic Immunity

Feb 26, 2020

Less than two months after China told the WHO there was a problem, a lot has happened. Sadly, deaths, confirmed cases and countries affected are increasing every day. However, on a scientific and medical level, what is going on to contain, cure and prevent this new disease is truly inspirational. Let’s look at the build-up to this global health emergency and what is being done by scientific teams all over the world to combat its effects. What we generally know COVID-19 is likely to have jumped from an animal to a human towards the end of last year (as with MERS and SARS, most likely bats). We can estimate this timing by looking at mutations accumulated by the virus over time, like a clock. The genetic sequence of COVID is very close (96 percent similar) to some coronaviruses in China’s … Read More

Prediction: NZ will probably never have another measles epidemic - Diplomatic Immunity

Feb 10, 2020

The Ministry of Health has announced a package that might ensure New Zealand will never experience another measles epidemic. While at the time of writing the details are still limited it appears that the important limitations in our current programme have been acknowledged and the intent is to address them. Great stuff. The commitment is starting with $23 million and more to come. The proposal to rebuild the immunisation register (NIR) is encouraging. The NIR is not only essential for keeping peoples immunization records but also for helping to identify people and communities that need additional services. Currently this electronic register it is very old and becoming very decrepit. An upgrade to this ailing and vital tool is urgent. Hopefully this will happen soon. It is also a useful tool for conducting vaccine effectiveness and safety studies so as far … Read More

2019-nCoV (the new coronavirus): Should we be concerned, and will there be a vaccine? - Diplomatic Immunity

Jan 22, 2020

Probably yes to both but don’t panic yet. There is a plan. What is this virus? 2019 novel coronavirus, aka 2019-nCoV, belongs to a family of viruses called coronavirus. These are very common viruses that infect a wide range of animals including humans and can cause mild to severe disease, from colds to severe pneumonia. Coronaviruses are often transmitted between animals and people (this means they are zoonotic). Well known examples are the Severe Acute Respiratory Syndrome (SARS-CoV) that made the leap from civet cats to humans in 2002/3, and the Middle East Respiratory Syndrome (MERS-CoV) that jumped from dromedary camels to humans in 2014. Both caused many deaths, MERS was more lethal. This new virus appears less aggressive that SARS and MERS. On New Year’s Eve China advised the World Health Organization (WHO) that they were seeing … Read More

The WHO Vaccine Safety Summit – from someone who was actually there - Diplomatic Immunity

Jan 14, 2020

The conspiracy I saw a new conspiracy theory flying around the other day. According to the conspiracy (that seems to originate from Del Bigtree), the World Health Organization have been ‘caught on camera’ questioning the safety of vaccines. Gosh this sounds as though someone was a mole at a secret meeting and filmed scientists admitting vaccines were not safe! Could this possibly be true? Short answer – NO! The Facts Actually, the event in question was live streamed in the public domain. You see, the cameras (there were several and I hoped none caught me in the background slouching after lunch) were contracted by the WHO in order to live stream the entire two-day Vaccine Safety Summit to the world – or at least whoever on the planet was interested and wanted to click on the … Read More

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