Last year, when governments recommended a range of protective measures such as mask-wearing, social distancing and lockdowns to slow COVID-19 infections, the number of influenza cases dropped dramatically compared with the seasonal average.

Cases this year have remained low, according to the World Health Organization (WHO), but with COVID restrictions being lifted in many parts of the world, children back in school, and the coronavirus continuing to spread, experts are urging people to remain cautious.

Experts have said it is difficult to predict the severity of the flu season in the Northern Hemisphere, but some have warned it could be challenging this year.

“Natural immunity wanes, so with little influenza last year, people are more susceptible,” Dr Robert Klugman, medical director of employee health at UMass Memorial Health in Worcester told Al Jazeera.

Dr Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, said people continue to take precautions against catching or transmitting COVID-19, which could lead to a milder flu season compared with those before the COVID pandemic.

According to Dr Saxinger the influenza season ordinarily “results in health care systems strained”.

According to the CDC, the health measures that help to protect against the flu are: avoid close contact with people who are sick, stay home when sick, wash hands regularly, avoid touching the eyes, nose or mouth, and cover the mouth and nose.

According to the WHO, the influenza season in the Southern Hemisphere this year was similar to the previous year.

“In Chile, the vaccination campaign started having an effect, there were also mobility measures well established, and the use of masks was mandatory,” Soto-Rifo said

However, as summer starts in the Southern Hemisphere, and some measures are relaxed, Dr Soto-Rifo said there are concerns that COVID-19 cases concerns could grow

“Children are good vectors of respiratory viruses, but keeping the measures in place helped,” Soto-Rifo said