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David Seymour: Vaccination Making Little Difference To Case Numbers

Vaccination rates are making little difference to infection rates under Omicron, which means it’s time to ask if the benefits of vaccine rules are still worth the costs to individuals, and social cohesion overall. Based on new evidence, it may be time to move on from Government vaccine mandates.


Taking the infection numbers of the past week by vaccination status, there is now little difference in the likelihood of a fully, partially, or unvaccinated person testing positive with Omicron. This data does not mean that vaccination is not useful or effective.


Vaccination is still your best bet for staying out of hospital, but even strongly pro-vaccine people like me have to confront what new evidence says about infection rates.


In the eight days from Friday 11-Friday 18, when Omicron cases really took off, there were 347 new unvaccinated cases, 140 new partially vaccinated cases, and 7,085 new fully vaccinated cases. These figures are not reported transparently, and have to be derived from the Ministry of Health Website.


Chart courtesy of Rodney Hide depicts updated MOH data to Feb 21, 2022


Of course, there are far more vaccinated than unvaccinated people, so the raw numbers do not tell the full story. For every 100,000 unvaccinated persons, 225 tested positive. For every 100,000 partially vaccinated persons, 204 tested positive, and for every 100,000 fully vaccinated 178 persons tested positive.


There are a number of possible explanations for why numbers between infection rates for vaccinated and unvaccinated people should appear so similar. For example, vaccinated people might be more trusting of or able to access the healthcare system, and therefore be more likely to take a test than unvaccinated people.


None of the explanations can really explain the similarity without accepting that vaccination makes a weak difference at best to whether a person tests positive for Omicron, however.


These new figures show how Omicron is changing the game, even since this time last month. On January 19, the Ministry of Health website reported half of all COVID cases up to that date had been unvaccinated and a quarter partially vaccinated. In the past week there have been 20 times more vaccinated cases than unvaccinated.



Chart courtesy of Derek Rankin


Those historical figures will be influenced by early stages of the pandemic, when nobody at all was vaccinated. However it is nearly impossible to know by how much with the data the Ministry of Health lets us have. In any event the past data does not change the reality we face now, Omicron is changing the numbers.


These figures are consistent with international evidence. Australia has similar vaccination rates to New Zealand’s but has experienced widespread Omicron outbreaks well beyond those who are unvaccinated.


It would be helpful if the Ministry of Health would start transparently publishing data for vaccination rates. At present, they update the cumulative number of vaccinated, partially vaccinated, and unvaccinated cases each day, but the number of new cases each day can only be derived by saving the data and calculating the change from day to day.


We face enormous mistrust and dissatisfaction with Government due to this kind of poor transparency that suppresses free and open debate. The Government should insist on the Ministry of Health making the data transparent, and even providing analysis so that any confounding variables can also be understood.


More importantly, it may be that Government policy needs to change direction. It is difficult to argue that there is not widespread transmission amongst vaccinated people. It seems unlikely that the 347 unvaccinated cases infected 7,085 others, around 20 each, but vaccinated people did not infect each other. This is particularly the case given vaccine mandates have largely segregated unvaccinated people from vaccinated people.


People have been led to believe for over a year that other people being vaccinated would protect them from being infected themselves. It appears that is no longer true, or at least the effect has been dramatically weakened.


All of this leads to a simple conclusion. If there is little difference in the rates of infection and spread of Omicron between vaccinated and unvaccinated people, then what is the point of segregating them? From the opposite perspective, if segregation is increasingly costly and undesirable, what sort of difference in infection rates would we require to justify it, and is the difference between 178/100,000 and 225/100,000 enough?


It is time to weigh up the costs that vaccine requirements are placing on individuals, on workplaces, and on social cohesion, and ask whether policies that force vaccination in various settings are still worth it. The case is becoming stronger by the day that they are not as Omicron spreads between vaccinated and unvaccinated in a way it did not do with earlier variants, and policies designed to prevent unvaccinated transmission are no longer worth it. It's time to move on.


David Seymour is the leader of the ACT Party


Data sources:

COVID-19 vaccination data through 15 Feb 2022 (Excel, 850 KB)

Ministry of Health Website COVID-19 Case Demographic page




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