Flu Is A Greater Risk This Winter, Not COVID

It has been five years since the first case of COVID-19 was reported in the US, since then it has unleashed winter waves of illness. It is the mutation of the strain, and every winter, there was a new one. However, this winter, COVID seemed much more muted, the hospitalization rates to have gone down. While it is a good news for the people, bad news and diseases have lingered in form of flu.

This winter season walking pneumonia, RSV, norovirus and bird flu, along with influenza grabbed more attention than COVID-19.

Why Are These Diseases or Viruses More Active In Winters?

Winter offers to best condition for airborne viruses to spread because this is the season when people travel the most or gather due to the holidays. People also spend more time indoors, go out in the sun much less. As per Demetre Daskalakis, who directs the Centers for Disease Control and Prevention (CDC)'s response to respiratory infectious-disease threats, "Right now, flu is the driver."

However, it is not easy to compare the previous winter COVID-19 waves with current cases as the data and its collection has changed. Hospitals no longer test every patient for covid, and official tallies are no longer available as more and more people are taking tests at home or not taking the test anymore. However, if one has to compare, it is best to rely on the CDC reports which notes that 38 out of every 100,000 people who were hospitalized this season had COVID-19, as of January 11. This is less than half the rate at the same point last year.

So, what changed this winter?

Unlike flu or RSV, COVID-19 stays even during the spring and in summer, and the COVID-19 wave this summer (2024) was worse than the one in 2023. This is why when winters arrived, it was much weaker, says Jennifer Nuzzo, an epidemiologist and director of the Pandemic Center at the Brown University School of Public Health, reports The Washington Post. “We had such a huge summer wave of infection, and that left in its wake a lot of immunity,” Nuzzo told the news outlet.

What this means is those who were exposed to COVID-19 in summer were less likely to become infected by the virus in the winters. While the virus has mutated, formed new strain, however, it has not evolved drastically.

When someone develops immunity against a virus due to vaccination, the virus then has to evolve to bypass the antibodies trained to block it to keep infecting people. While there has been accounts of the XEC variant, for half of the new cases, it is not necessarily very different from the KP and FLiRT strain.

“We are definitely moving in a very similar axis of viruses where there’s not been like a sudden shift or a change that evades immunity,” Daskalakis told The Washington Post.

However, having said that, it does not necessarily mean that by each winter, the virus will get weaker, because there is a fair chance for the virus to evolve and more threatening variants to emerge. This could affect people because while most Americans got their first COVID-19 shots, they were much less willing to get booster doses.