It was the winter of 2019 and the world was readying to welcome the New Year with all the traditional merry. But, the last few weeks, like we all remember, turned everybody’s lives upside down with a unique virus — first reported in China — invading our lives.

Four years later, the Covid-19 pandemic has abated, but the virus continues to exist in our lives in its many evolutionary forms.

Covid-19 saw three big mutations in December of 2020: Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1). A year later, in December 2021 the Omicron variant sent the world back into their homes just months after lockdowns began to ease.

The next year, in December of 2022, while there was no emergence of a new major variant, we saw the rise of subvariants such as BA.2 and BA.5, all classified within the Omicron branch of the coronavirus.

And now we have the JN.1 variant, which also belongs to the Omicron lineage.

A recurring feature in these variant evolutions is December, the cold winter month that first introduced the novel coronavirus (as it was known in 2019 and early 2020) into the world.

Why is it always December? We will analyze that, but first, let's understand this new variant.

WHAT IS JN.1?

The latest mutation of the coronavirus, dubbed JN.1, has been declared as a 'variant of interest' by the World Health Organisation (WHO) due to “its rapidly increasing spread” across the world. It has already been detected in many countries, including India, China, the United Kingdom, and the United States.

Part of the BA.2.86 lineage, which is a descendant of the Omicron or B.1.1.529 variant of SARS-CoV-2. JN.1 comes equipped with an additional mutation in the spike protein.

SO, WHY DECEMBER?

A study published in the journal Nature, conducted to analyze the onset of the second wave triggered by the Delta variant, showed that during the first wave of the pandemic, weather conditions affected how easily the virus spread.

As we moved from summer to winter, the temperature dropped, and the air became drier, contributing to an intense second wave of COVID-19 in countries in the Northern Hemisphere.

Researchers at China's Sichuan International Studies University also confirmed a similar hypothesis. Their study found that participants, living in cold conditions, reported a higher likelihood of contracting the coronavirus than participants in controlled (warmer) conditions.

Experts have continuously maintained that there is no need to panic, but do advise caution citing human behavior that keeps changing.