Can scented candles be used to indicate surging waves of COVID-19?

A research paper found that Amazon reviews complaining of no scent on Yankee Candles seem to coincide with surging rates of COVID-19.

Scented Yankee Candles. (photo credit: ODELYAKNOWS)
Scented Yankee Candles.
(photo credit: ODELYAKNOWS)

Amazon reviews on scented Yankee Candles may be able to indicate when COVID-19 waves are on the rise, according to a research paper published recently on the subject.

Loss of sense of smell is one of the known symptoms of COVID, but some people don't realize they've lost this until they do a task specified to smelling such as lighting a scented candle or applying perfume.

As a popular brand of scented candles, the research paper looked at Amazon reviews of Yankee Candles purchased at different times. It then used the statistics Bayesian vector autoregression method to compare times when "no scent" reviews rose on Amazon with times when COVID rates rose.

What did the results show?

Yankee Candles have an average rating of more than four stars on Amazon, indicating that customers are usually very pleased with their purchases, but at certain periods, the reviews were less enthusiastic. 

 SARS-CoV-2, the novel coronavirus behind COVID-19 (Illustrative). (credit: fusion medical animation/unsplash) SARS-CoV-2, the novel coronavirus behind COVID-19 (Illustrative). (credit: fusion medical animation/unsplash)

The results showed that in December of 2021, Amazon received more reviews than normal from customers in the US that the Yankee Candles didn't have a scent. This data was shown to parallel a large wave of COVID in the US at the time.

This trend was once again confirmed later in the year when a rise in "no scent" reviews coincided with another wave of COVID.

While the research paper shows convincing data for the case of "no scent" reviews acting as an indicator in rising COVID rates, this is not definitive proof that the method is foolproof, and further research is required.

For now, Dr. Jorge Cabarello posted screenshots on Twitter showing another rise in "no scent" reviews. Can this mean that COVID is surging once again in the US?