Unvaccinated people 11 times more likely to die from COVID-19, CDC Director
A new report from the US Centers for Disease Control and Prevention (CDC) has indicated that the COVID-19 vaccines still hold strong against the Delta variant (Delta) of the coronavirus. The report, which offered insights into the effect of Delta on vaccine effectiveness, further stated that vaccinated people were less likely to suffer hospitalisation or death from COVID-19 than unvaccinated people, even as infections caused by the Delta variant continues to crop up.
Looking at more than 600,000 COVID-19 cases across 13 US states between early April and mid-July this year, in which Delta accounted for more than 50% of all infections, the CDC found that while the number of symptomatic cases in vaccinated people did increase as Delta spread, rates of hospitalisations and death did not rise. Vaccine effectiveness against basic symptomatic infection dropped from 91% to 78% as Delta became predominant; at the same time, protection from hospitalisation only dropped from 92% to 90%, and protection from death dropped from 94% to 91%.
Although Delta accounts for more infections in vaccinated people, the rise in hospitalisations and deaths are primarily in those unvaccinated – a strong indicator that the vaccines still offer robust protection from this dangerous variant.
Another report by CDC showed unvaccinated individuals were between five and seven times more likely to need emergency department care due to COVID-19 compared to those vaccinated. This report looked at over 32,800 cases of COVID-19 between June and August, also the period when Delta had become predominant.
Read: COVID-19 vaccination effective against delta variant, researchers say
CDC Director Rochelle Walensky recounted: “Looking at cases over the past two months, when the Delta [variant] was the predominant variant circulating in this country, those who were unvaccinated were about four and a half times more likely to get COVID-19, over 10 times more likely to be hospitalised, and 11 times more likely to die from the disease.”
The latter study even suggested differences in effectiveness between two commonly used mRNA vaccines, Moderna and Pfizer. The Moderna vaccine was noted to be up to 95% effective at preventing COVID-19 hospitalisation, compared to 80% for the Pfizer vaccine.
It is unclear exactly why there could be efficacy differences between Moderna and Pfizer’s relatively similar mRNA vaccines. One hypothesis suggests it could be because Moderna’s vaccine doses are significantly higher than the Pfizer vaccine, but there are plenty of other factors that could be influencing these mRNA vaccine differences. For example, this particular study did not track time since vaccination, so it is unknown whether waning efficacy accounts for these differences.
According to Dr. Shaun Grannis, from the Indiana University School of Medicine, the biggest takeaway from these reports is that vaccines are still extraordinarily potent against severe COVID-19 caused by the Delta variant: “Despite the differences in effectiveness, vaccines continue to offer much more protection than not getting one at all – COVID-19 vaccines are powerful tools for combating the pandemic.”
