COVID-19 Vaccine Effectiveness In Data | Over 120 Countries at Risk for New COVID Spikes

(Published: 23 June 2021. Updated: 29 July 2021) Since the beginning of the pandemic, vaccination has been seen by many experts as a key unknown in the post-COVID economic recovery puzzle. While countries' progress in COVID vaccinations can be tracked directly, cross-country comparisons of data on COVID-19 numbers and vaccination progress also make it possible to begin to examine how effective vaccination has been in preventing the spread of the disease and minimizing its consequences.

In this dashboard we compare the progress in COVID vaccinations (measured as the total number of vaccines administrated per hundred population) with the number of new daily COVID-19 cases and deaths across more than 170 countries, using data collected by Our World In Data. 

What we discovered:

• We did not initially find a strong inverse relationship between vaccination progress and the number of daily COVID-19 cases, nor a particularly strong inverse relationship between vaccinations and COVID deaths. This is perhaps to be expected; besides the percentage of a population that is vaccinated, the number of COVID-19 cases and deaths depends on many other factors such as the stringency of anti-COVID restrictions, the upward/downward phase of the pandemic wave, access to health care services and resources, different virus strains, and the variety of vaccines used. The reliability and consistency of COVID-19 statistics may also be a factor.
• That said, when several outliers are excluded, the remaining countries' data demonstrates the expected pattern: the more people in a country get the vaccine, the lower the number of COVID-19 deaths. Countries where the number of vaccine doses administered exceeds 60 per hundred population register fewer than four new deaths per million population per day on average. 
• The outliers — countries that have relatively high number of COVID-19 deaths as well as strong progress in vaccination (over 80 vaccines administrated per hundred population) — are Chile, Mongolia, Seychelles, and Uruguay. Three counties from this list — Chile, Seychelles, and Uruguay — used primarily Chinese-made vaccines.
• In terms of daily COVID-19 cases, the comparison with current vaccination rates indicates that countries with higher progress in vaccination can have the same number of new cases per million per day as countries with a lower proportion of the population vaccinated, suggesting that vaccination alone isn't preventing the spread of the virus, at least not at current vaccination rates.
• These numbers suggest that widespread vaccination does have the potential to dramatically curb COVID's impact — but they also highlight the risk for countries with low vaccination rates. Based on the cutoff points noted above for decreasing death rates, more than 120 countries may be at significant risk for new deadly waves of COVID-19.
• A comparison of the COVID-19 death rates among major world economies shows a significant difference between countries with very high and very low vaccination rates. Those with slow vaccination progress have not been able to reduce their COVID deaths; in Indonesia and Russia the number of new COVID deaths has increased in recent months, and Brazil has struggled to recover from a major surge. In the US, the UK, Canada, and Israel, where vaccination rates are much higher, the number of deaths has declined, though the UK has experienced an upsurge in recent weeks.
• On the other hand, the UK and some other European countries where cases are increasing serve as a reminder that vaccination progress is not a guarantee against a new surge in COVID cases.

Note: Knoema's analysis cannot be used for the purpose of making any decisions related to vaccination. It is intended to be used for informational purposes only and does not constitute medical advice.