- Experts say the flu season in the United States could start early this year.
- They add the illness could also be stronger this season due to the low number of cases during the COVID-19 pandemic, a situation that has produced a gap in immunity.
- They say the best time to get vaccinated is probably in September or October.
- They note the vaccines’ protection last from four to six months, so it’s important not to get vaccinated too early.
The Southern Hemisphere has been experiencing an unusual surge in flu cases early this season and experts say the same could happen in the United States later this year.
The Australian flu season usually spans from May to September, but this year the number of flu cases from mid-April exceeded the 5-year average.
“The Australian experiences is suggestive that this could be a really bad flu season in the Northern Hemisphere as well,” Dr. Dean Blumberg, the chief of pediatric infectious diseases at the University of California Davis Children’s Hospital, told Healthline.
Blumberg says the influenza season in the United States has been unusual since the COVID-19 pandemic began and this could have consequences for this year’s season.
“We saw historically low rates of influenza during that 2021 flu season and relatively low rates during 21/22 in the U.S., and yet, we had lingering influenza cases that occurred in May and June and we were still seeing patients admitted to the hospital in May and June, treating them for influenza, which is highly unusual,” he said.
“I worry about it because I think with all the social distancing and mask wearing people have not been getting infected, which is a great thing, but they also haven’t been building up immunity,” Blumberg explained. “So those people who don’t get immunized, there’s going to be a significantly larger proportion of them who don’t have any recent experience with influenza infections. And that could lead to a higher rate of infection and also more severe cases.”
In Australia so far this year, children younger than 5 and those aged between 5 and 19 had the highest rates of reported flu.
Flu shot recommendations
For the 2022/2023 flu season, the U.S. Centers for Disease Control and Prevention (CDC) advises that every person over 6 months of age should be vaccinated against flu.
This year, there are six options for the flu vaccine, including egg-free vaccines, a nasal spray vaccine, and higher potency vaccines for those aged 65 and over.
In June, the CDC’s Advisory Committee on Immunization Practices voted to preferentially recommend three higher potency flu vaccines for people aged 65 and older.
In this age group, these specific vaccines may produce a more effective immune response than the standard dose.
“Fortunately, everyone aged 65 and older, in essence in the United States, is a Medicare recipient. And for them, there is no out-of-pocket cost for influenza vaccine, including these vaccines,” Dr. William Schaffner, an infectious disease expert at Vanderbilt University in Tennessee, told Healthline.
“Each year, we vaccinate two-thirds of the population aged 65 and older. That’s a great achievement. But interestingly enough, it means that a third of people in the United States 65 years of age and older, the very population that suffers disproportionately the most severe aspects of influenza, do not avail themselves of the vaccine. When it’s free. As I like to say, all they have to do is roll up their sleeves,” Schaffner said.
When to get a flu shot
In recent years, experts say manufacturers of vaccines have shipped their products to pharmacies, hospitals, and clinics relatively early in the flu season. But experts stress it is important not to get the flu vaccine too early, even if it is available.
“Historically, we’ve been recommending as soon as the influenza vaccine is available. However, with recent data showing that the protection lasts between four and six months it’s been recommended by some to push back the vaccination date to late September or early October to provide the maximum protection during the peak months of infection,” Blumberg said.
The CDC advises it is best to get vaccinated before influenza starts circulating in the community, with September and October being good times to be vaccinated.
It advises that ideally everyone should have received their influenza vaccination by the end of October.
However, in some cases, early vaccination can be considered. Some children require two doses of flu vaccine and these children can get vaccinated with their first shot as soon as vaccines are available, even if this is in July or August.
Those in the third trimester of pregnancy can also consider an early vaccination.
It will take two weeks following vaccination for antibodies to develop to protect against an influenza infection.
Experts say relying on last year’s vaccine is not a good idea, as protection from the vaccine decreases over time and the influenza virus changes every year, which is why an annual vaccine is necessary.
“We have to adapt the vaccine. We have to update it in order to account for the strains that we think will be more prominent to come in the winter,” Schaffner said.
With a “twindemic” of both COVID-19 and influenza expected this winter, experts say the influenza vaccination is an important tool to prevent respiratory illness.
“I would hope people would take advantage of a simple preventative measure, to get the influenza vaccine to try to prevent a respiratory illness,” Schaffner said. “And then also think about, if you do get influenza, you’re going to have a fever, you’re going to have a cough, you’re not sure what you have at the time, you’re probably going to be worried that you have COVID. So who needs that anxiety?”