Science – Defeating Delta

The Delta variant of Covid-19 is by far the most contagious and dangerous genetic form to appear so far. This variant has been detected over the past month in the wider Warkworth region. In a community in which few are vaccinated but all are exposed to the virus, most of the unvaccinated would become infected but most of the vaccinated would not. A combination of vaccination and mask wearing are the most effective strategies for stopping Delta. Vaccination protects against serious illness and death, and masks protect against casual transmission.

Within just a few months, the Delta strain has spread rapidly to over 98 countries. The importance of double vaccination is demonstrated by studies showing 95 per cent efficacy against the Delta variant after two Pfizer jabs.

At the time of writing, two thirds of the eligible New Zealand population have been vaccinated. The percentage unvaccinated is dropping at roughly 10 per cent per week, so a national target of 90 per cent fully vaccinated is certainly achievable within the coming months.

Until we achieve much higher levels of vaccination (perhaps greater than 90 per cent), there is a genuine risk that new even more dangerous and vaccine-resistant variants may emerge. The actual global mortality due to this pandemic (18 million deaths) is far less than that of the 1918 influenza pandemic (100 million deaths). The lower fatality rate has emerged, even though the planet now has three times the 1918 population. The lack of knowledge about virology and the absence of an established vaccine were key factors in the massive mortality in the years around 1918. In 2021, we have the benefit of access to several thoroughly tested, safe and effective vaccines.

Rejecting vaccines in 2021 is a voluntary 100-year step back into the throes of one of the more deadly pandemics in human history.

What are some of the expected costs of not being vaccinated in a community with low vaccination rates? The primary cost is obviously the possibility of serious illness and even death of the individual, but there’s more.

Unvaccinated individuals who have unvaccinated relatives and close friends are spreading the infection risk to their whanau. Unvaccinated individuals who deal with the public in their employment are likely to spread the risk of very serious illness to many in the community. Access by unvaccinated individuals to cafes and restaurants and major entertainment events will be blocked, as has happened in many other countries. Failure to achieve full vaccination will have a major impact on many economic sectors by preventing the restoration of materials and product supply chains. Unvaccinated individuals will not be permitted to travel internationally to visit family and friends. The economic costs of hospitalisation of such individuals given the contagious nature of the virus are very high. In some countries, the increased burden on health systems has led to the breakdown of their national health systems.

If as a caring local community, we can achieve a greater than 90 per cent vaccination rate, we will suppress Delta and will prevent numerous avoidable cases of serious illness and death.