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Covid-19 vaccine promising results – Expert Reaction

Results from a trial of a leading vaccine suggest it could protect over 90% of people from Covid-19 infection.

The Pfizer/BioNTech vaccine uses a new technology which involves injecting genetic code from the SARS-CoV-2 virus in order to train the immune system. Last month, the New Zealand government announced an agreement with Pfizer for a supply of 1.5 million doses of this vaccine, subject to clinical trial results.

The SMC asked experts to comment on this news. 

Associate Professor Helen Petousis-Harris, Vaccinologist, University of Auckland, comments:

“I am excited! This time last year COVID-19 was unheard of. Between January and November this year, a mind boggling number of vaccines are galloping through development with several up for the big reveal. The Pfizer RNA vaccine has so far been tested in over 44,000 people and early data show a 90% vaccine efficacy rate. The result could not be much better, and thanks to an agreement signed a few weeks ago, NZ has 1.5 million doses of this vaccine scheduled to arrive early next near. This is all fantastic.

“There are few things to note. This is early days, and we do not know how long the protection will last for, we do not know if the vaccine can help community immunity by preventing the carriage and transmission of the virus, and because the numbers are too small so far, we do not know if it protects against severe disease, although I would have some optimism about this.

“There are still some groups that the vaccine will need to be assessed in. The safety looks fine so far, nothing serious, but quite a few people receiving the vaccine can feel a bit flu-ish after for a while as their body makes an immune response – not enough to put them off getting two doses in the trial, and not unlike quite a few other routinely used vaccines.

“While RNA vaccines are new and none have ever been approved for widespread use in people, there are no down-sides to them that I am aware of other than the current need for most of them to be stored at – 70 degrees Celsius, necessitating some pretty serious cold chain arrangements.

“So far this vaccine pushes all the right buttons to be successful. This is very good news indeed!”

Conflict of interest statement: Helen Petousis-Harris is an investigator on industry-funded studies and has served on expert advisory boards for industry. She does not receive personal honoraria.

Dr Nikki Turner, Director Immunisation Advisory Centre, University of Auckland, comments:

“While we await the release of the full scientific evidence we can only go by the initial reporting in the media. The press release news looks very promising, and gives us optimism that there will be an important role for vaccines in helping manage the devastation of COVID. It is great to celebrate the first evidence coming from a pivotal randomised control trial showing that this vaccine has the potential to be very effective. The study is well designed and with good numbers, suggesting these findings are likely to be robust. This is really exciting.

“However, there are still a few important steps to go through before  this vaccine can be used safely in communities.  The full results of this study, both the efficacy and the safety results, need to go through appropriate scientific scrutiny by the important international licensure bodies and, before we use it in NZ, the NZ licensure body, Medsafe.

“Furthermore, there are still important unknowns – while a figure of 90% effective sounds really great, we are unclear if there are some groups who are less likely to respond to a vaccine than others, and we have not yet seen any data on whether it is more effective against severe disease.  We do not know as yet how long the protection is likely to last for. And importantly for NZ, we do not know how effective this vaccine may be against spreading the disease to others. Some vaccines can reduce the chance of getting sick but may not stop the ability of the virus to spread between people. This is a crucial question if we wish to try and maintain minimal community transmission.

“Most other countries urgently need vaccine to reduce severe disease, whereas we wish to try and keep the disease out of the country as much as we can. So while this is very promising  news today, we need to maintain caution and continue with our careful scientific approach.”

No conflict of interest

Professor David Murdoch, Clinical Microbiologist and Infectious Diseases Physician, Dean and Head of Campus, University of Otago, Christchurch, Co-Director, One Health Aotearoa, comments:

“Today, Pfizer and BioNTech announced the interim analysis of a phase 3 trial of their COVID-19 vaccine candidate, reporting that it is more than 90% effective in preventing COVID-19 in people without evidence of prior SARS-CoV-2 infection.

“This is an early analysis at a stage when 94 COVID-19 infections have been recorded so far in a study that has enrolled nearly 44,000 participants. This level of effectiveness is certainly very encouraging and is higher than many would have anticipated.

“However, this is not the final analysis of the study, which is planned when a total of 164 confirmed COVID-19 cases have been recorded. Once these final results are available and peer-reviewed we will have a more precise estimate of the vaccine’s effectiveness, as well as detailed information on safety and how effective the vaccine is against severe disease. We also do not know yet how long immunity will last following vaccination.

“The Pfizer/BioNTech vaccine is also of great interest to the scientific community because it uses a completely new technology. This involves injecting the SARS-CoV-2 virus’s genetic code (RNA) in order to train the immune system.

“The New Zealand government announced last month that it had signed an agreement with Pfizer for the supply of 1.5 million doses of this vaccine, subject to the vaccine successfully completing all clinical trials and passing regulatory approvals in New Zealand.”

No conflict of interest

Additional comment from the UK Science Media Centre:

Prof Toby Peters, Professor of Cold Economy, University of Birmingham, comments:

“Efforts to find a lasting solution to the COVID-19 pandemic have been focused on developing, testing and manufacturing at scale an effective vaccine. However, little attention has been given to what is needed to distribute it rapidly at scale.

“In order to protect both efficacy and safety, most vaccines must be maintained at a specific temperature, normally 2-8C. The new two-shot vaccine from Pfizer has to be maintained at -80°C – nowhere on the planet does the logistical capacity exist to distribute vaccines at this temperature and volume without massive investment.

“The problem is particularly acute in the Global South where many rural villages don’t even have a working vaccine fridge. We must take this once-in-a lifetime opportunity to create sustainable solutions for COVID-19 vaccine deployment that also can deliver resilient and sustainable health cold-chain systems, including ultra-low temperature.

“Temperature management at -80°C is a tough challenge but we cannot allow this to become, by default, a divided solution. Research suggests equitable distribution of the COVID-19 vaccine globally would prevent 61% of subsequent deaths, compared to 33% of deaths avoided if it is distributed to high-income countries first.”

No conflict of interest