Age and Infection Fatality Rates (IFR) - GTEC Green Technology Education Centre

By Ross Thrasher

The world is now approaching 100 million COVID-19 cases, and 2.1 million have died from the pandemic. So the global Infection Fatality Rate is just over 2%. But the age distribution of this IFR is heavily skewed.

A recent analysis of 27 studies across 34 locations finds “an exponential relationship between age and IFR for COVID-19. The estimated age-specific IFR is very low for children and younger adults (e.g., 0.002% at age 10 and 0.01% at age 25) but increases progressively to 0.4% at age 55, 1.4% at age 65, 4.6% at age 75, and 15% at age 85. Moreover, our results indicate that about 90% of the variation in population IFR across geographical locations reflects differences in the age composition of the population and the extent to which relatively vulnerable age groups were exposed to the virus.

“… These results indicate that COVID-19 is hazardous not only for the elderly but also for middle-aged adults, for whom the infection fatality rate is two orders of magnitude greater than the annualized risk of a fatal automobile accident and far more dangerous than seasonal influenza. Moreover, the overall IFR for COVID-19 should not be viewed as a fixed parameter but as intrinsically linked to the age-specific pattern of infections. Consequently, public health measures to mitigate infections in older adults could substantially decrease total deaths.”

Source: https://www.medrxiv.org/content/10.1101/2020.07.23.20160895v7.full

Canada’s IFR by age is consistent with this pattern. Of the 52,000 COVID-infected Canadians 80 years and over, 23% have perished. The IFR for 70-79 is just under 10%, 60-69 drops off to 2%, 50-59 is 0.4%, and younger groups are less than 0.1%. Canada’s overall IFR is 2.54%. Source: Health Canada.

Some countries have shown a wide variance from the 2% global mean IFR. Mexico, which is currently experiencing its worst spike in cases and deaths, has an IFR of 8.5%. However, only 3.3% of Mexicans have been tested for the virus, so the true rate is probably much lower. Conversely, nations that have tested almost everybody, e.g. Israel, UAE, Bahrain, Denmark and Iceland, have IFRs below 1%. Other variables like a younger population, better medical facilities and of course greater adherence to public-health guidelines can also reduce these IFR percentages.

Newly-inaugurated US President Biden has said of the pandemic “It’s going to continue to get worse before it gets better”. It is indeed worse than ever right now, with more than 12,500 American COVID fatalities in the past three days. Biden has pledged 100 million vaccinations across the country in the next 100 days, but cities like New York and L.A. are already running out of shots.