Research in the United States shows that the Delta variant does not affect the effectiveness of the Covid-19 vaccine as previously warned.
The Delta variant (B.1.617.2) was previously warned by many experts for its potential to evade vaccines due to dangerous mutations. However, in a paper published on medRxiv (awaiting peer review), a team of experts from the Argonne National Laboratory in the United States affirmed that the effectiveness of the vaccine is not affected by the Delta variant.
Vaccines are currently the best measure to protect us from the Delta variant.
With its rapid spread, the Delta variant has appeared in over 140 countries and territories, accounting for 98% of cases in the United States. The expert team used data from public health agencies in 7 states, 5 counties, and Columbia to collect test results. They also evaluated vaccination outcomes from May 15 to September 15. This period coincided with Delta dominating new cases in the U.S., at times reaching up to 100% of cases.
The authors confirmed that the effectiveness of the vaccine remained very high across the United States from mid-May to late August, with only Washington showing a slight decrease in vaccine effectiveness against Covid-19 at the end of June.
On average, the effectiveness index of the Covid-19 vaccine (measured by its ability to combat nCoV infection, determined through rRT-PCR testing) remained at 0.7-0.9, unchanged even during the peak spread of the Delta variant.
Another factor is the viral load. Unvaccinated individuals (F0) have increased viral loads, making them more susceptible to severe illness. In contrast, vaccinated individuals who contract Covid-19 exhibit a strong immune response, leading to a rapid decrease in their viral load and quicker recovery.
The average age of vaccination has decreased by 4.4 years compared to the summer of 2021. Consequently, the effectiveness of the vaccine may increase as more young people get vaccinated during the Delta spread.
The expert team emphasized that vaccines are currently the best measure to protect us from the Delta variant. Additionally, the effectiveness of the vaccine varies among different age groups.
“From the research data, we conclude that there is no evidence that the Delta variant escapes the immunity provided by the Covid-19 vaccines currently in use in the United States,” the research team wrote.
