We at ADHS are pleased to have contributed to a recent Centers for Disease Control and Prevention (CDC) report offering a new and very useful way to look at the effectiveness of COVID-19 vaccines in light of rare breakthrough cases among the fully vaccinated.
A key takeaway from this report in the CDC’s Morbidity and Mortality Weekly Report: COVID-19 vaccination has continued to provide robust protection against hospitalization and death even after the highly contagious Delta variant became the dominant variant in late June. If you aren’t fully vaccinated and get COVID-19, your risk of being hospitalized or dying is more than 10X higher than that of someone who is fully vaccinated.
Analyzing information from Arizona and 12 other states, the report examines the difference between unvaccinated and fully vaccinated individuals ages 18 and older when it comes to COVID-19 cases, hospitalizations, and deaths. It uses rates of each outcome among each group to develop a ratio of how much more likely one group is to have that outcome. The public health term for this comparison is incidence rate ratio (IRR).
The report also examines these ratios before and after late June, when the highly contagious variant known as Delta became the overwhelmingly dominant COVID-19 variant.
In a nutshell, here’s what it found:
- Before late June, those who weren’t fully vaccinated were 11.1 times more likely to get COVID-19 than fully vaccinated individuals. After late June, when Delta was the dominant variant, those who weren’t fully vaccinated were 4.6 times more likely to get COVID-19.
- Before late June, those who weren’t fully vaccinated were 13.3 times more likely to be hospitalized than fully vaccinated individuals. After late June, those who weren’t fully vaccinated were 10.4 times more likely to be hospitalized from COVID-19.
- Before late June, those who weren’t vaccinated were 16.6 times more likely to die from COVID-19 than those who were fully vaccinated. After late June, they were 11.3 times more likely to die from COVID-19 than those who were fully vaccinated.
If you think that means vaccines aren’t protective, think again. As with the flu vaccine, the COVID-19 vaccines protect against serious illness and death while reducing the transmission of disease. These findings are consistent with other recent studies showing decreased vaccine protection against confirmed COVID-19 infection, when the Delta variant has predominated and immunity from the vaccine may be waning in the population. But they also suggest that vaccines continue to offer stable, strong protection against hospitalization and death.
As with every analysis, there are limitations. But the results are consistent with other studies and what public health has been saying about the continuing effectiveness of the safe, free, and widely available COVID-19 vaccines. They are still achieving their purpose of protecting people against COVID-19, especially severe illness and death .
We strongly urge you to roll up your sleeve and get vaccinated today at one of the hundreds of providers around Arizona. The vaccine is our best line of defense against COVID-19. It protects you, those you love, and your community.