The onset of the respiratory disease season, which began with a sluggish pace, now looms with a menacing potential to escalate due to the perilously low vaccination rates. This could reverse the initial trend and significantly heighten the risks for children, as certain illnesses are already on the rise.

The US Centers for Disease Control and Prevention (CDC) forecasts a grim possibility that this season might mirror or even surpass the severity of the previous one. Astonishingly, the peak hospitalization rates for respiratory viruses are projected to not only match but potentially exceed historical averages recorded prior to the Covid-19 pandemic.

Contrastingly, Covid-19 cases in the US are currently at their nadir since the pandemic's inception, with a continued downward trajectory as indicated by early December CDC data. Despite minimal circulation levels of influenza and respiratory syncytial virus (RSV) as suggested by wastewater surveillance, emergency department visits for these viruses have begun to climb precipitously.

The trajectory of the season is cautioned to be subject to change by numerous variables, with Dr. Andy Pekosz, a virologist at the Johns Hopkins Bloomberg School of Public Health, noting, "Historically, we observe a surge in cases approximately one week post-Thanksgiving, and the rate at which cases escalate between then and the Christmas holidays provides a clearer indication of the season's severity."

The CDC's forecasts for the respiratory disease season incorporate the specter of new Covid-19 variants, yet vaccination is deemed pivotal in mitigating hospitalizations for influenza, Covid-19, and RSV. The current Covid-19 vaccination rates remain stagnant, mirroring levels from the same period last year, with less than one in five adults and approximately one in twelve children having received the updated Covid-19 vaccine for this season, as revealed by CDC data.

A Pew Research Center survey published last month indicated that approximately 60% of adults are disinclined to receive the updated Covid-19 vaccine, with most citing a belief that they do not need it or concerns about side effects; about a quarter expressed a general aversion to vaccinations. Flu vaccination rates are similarly abysmal, with only about 37% of adults and 33% of children having received their flu shots this season, as per data through mid-November. The CDC's data shows that the flu vaccination rate among children is significantly lower than in previous years, nearly 12 percentage points below the season prior to the pandemic and 5 percentage points lower than last season.

Elizabeth Choma, a pediatric nurse practitioner at Loudoun Medical Group and an assistant professor at the George Washington University School of Nursing, elucidates, "While vaccines do not guarantee that a child will avoid illness, they generally offer sufficient immune support to ensure that the illness is less severe."

For instance, flu statistics reveal that the majority of pediatric deaths from influenza occur in unvaccinated children. Respiratory diseases pose unique risks to children, as Choma further explained: "Infants, toddlers, and preschool-age children have smaller airways, which makes breathing more difficult when their airways become inflamed. Additionally, infants are obligate nasal breathers, relying on nasal respiration. When congested, it becomes harder for them to breathe and perform everyday activities such as drinking, increasing their risk of dehydration."

RSV infections, typically mild in adults, pose a higher risk of severe disease for infants and the elderly. CDC data shows that the test positivity rate for RSV is increasing significantly faster than for flu or Covid-19, and the hospitalization rate is rapidly rising among children—with approximately 3 RSV hospitalizations per 100,000 children during the week ending November 23, double the number from a month prior. There were at least 21 hospitalizations per 100,000 infants that week, up from less than 14 a month earlier. In contrast, the hospitalization rate for adults has not exceeded 0.5 so far this season.

Another respiratory disease, walking pneumonia, caused by the bacterium Mycoplasma pneumoniae, is spreading rapidly among young children, and children's hospitals are feeling the strain. The CDC first warned of an increase in these infections in October, and the situation has not improved. Cases began to rise globally in 2023 after a few years of reduced spread during the Covid-19 pandemic. However, surveillance data from the US this year suggests that hospital visits peaked in August and have remained high since, particularly among children. The increase in children aged 2 to 4 is especially noteworthy, as walking pneumonia is not typically a leading cause of disease in this age group, according to the CDC.

Surges in respiratory diseases can strain hospital systems and exacerbate ongoing supply chain challenges, particularly in busy emergency departments, said Dr. Torey Mack, chief medical officer for the Children's Hospital Association. Just a few weeks into the respiratory disease season, some children's hospitals are already feeling the impact, she noted. For instance, the emergency room at Cook Children's Medical Center in Fort Worth, Texas, is nearing capacity as hospitalizations for RSV and pneumonia increase.

Pediatric pneumonia cases requiring hospitalization have also spiked in central Virginia, and Dr. David Marcello, chief of pediatric hospital medicine at Children's Hospital of Richmond at Virginia Commonwealth University, suspects that this trend is "likely to worsen with rising pollen and mold counts, colder weather keeping everyone indoors, and the holidays bringing people together."

"Children's hospitals have learned from past years to anticipate this surge around this time of year and have the specialists needed to care for children, especially younger children who are more severely impacted by respiratory illnesses," Mack said. "Given that the needs based on the impacts of respiratory illnesses can increase dramatically, it is essential that children have access to the care they need and the expertise of pediatric specialists who can act promptly."