Lockdowns and School Shutdowns May Make Youngsters Sicker

Evidence is ample that stress and inactivity weaken immunity against Covid and other diseases.

Photo: Getty Images/iStockphoto

Parents and public officials have been asking if it’s safe to send children to school this fall. They should also ask if it’s safe not to. A large body of medical literature suggests that stress and its symptoms, including mental illness, tend to weaken the immune system, leading to inflammation and greater susceptibility to infectious diseases. Lockdowns combined with school closures have been hugely stressful for families. Today’s stressed children could be more vulnerable to disease later in life—or to Covid-19 now.

In a Harris poll conducted in late April, about a month into lockdowns, 46% of parents with children under 18 reported high stress levels related to the pandemic, compared with 28% of childless adults. Seventy-one percent of the parents said managing online learning was a significant source of stress.

A University of Wisconsin study assessed the effect of school closures and sports shutdowns on those of high-school age. It found the rate of mild to severe depression increased from 31% to 68% in May while physical activity (measured by the Pediatric Functional Activity Brief Scale) fell by half. In a study of primary-school-age children who were confined to homes in China’s Hubei province for an average of 34 days, almost 1 in 4 reported depressive symptoms. Scientists hypothesized this was a result of “the reduction of outdoor activities and social interaction.” Public-health officials have also warned that child abuse has increased during the lockdowns, though this is hard to prove: Fewer cases are detected and reported while schools are closed.

Stress is normal and can even be healthy if alleviated with exercise, social support and other forms of recreation. But when it builds up, the immune system can go haywire, both underreacting and overreacting—including for patients who get severely sick with Covid-19.

A seminal 1991 study found that people who reported high levels of psychological stress were significantly more likely to become infected with common cold viruses after exposure. This was true even of those who had antibodies to the viruses. One reason is stress suppresses the “natural killer” and T-cells that are the immune system’s frontline of defense against viruses.

Scientists have found evidence that people who were previously infected with coronaviruses that cause the common cold have T-cells that attack Covid-19 in vitro. This pre-existing T-cell immunity may be one reason not everyone exposed to Covid-19 gets sick. Yet coronaviruses are so common that it’s unlikely previous exposure is sufficient to stave off Covid symptoms.

One reason may be that high levels of stress suppress T-cell response. A 2014 study in the Journal of Immunology compared the immune responses of 5-year-old children based on family stress levels. Kids from families with higher stress levels had a “suppressive immune response” and “a low spontaneous activity” of T-helper cells, which activate antibodies and other white blood cells.

At the same time, more-stressed children had higher levels of pro-inflammatory signaling molecules called cytokines, which have been linked to autoimmune diseases as well as severe cases of Covid-19. Cytokines are “known to be enhanced by psychological stressors such as depression and abuse in childhood,” the study explained.

What’s more, the study noted, stress can impair a type of T-cell that helps keep the immune system in check and thus “might result in an exacerbation of inflammatory conditions such as an autoimmune condition.” Clinical physicians have observed that severely ill Covid-19 patients at first muster a lethargic T-cell response to the virus but then overreact with a “cytokine storm.”

Studies have also suggested that childhood stress can lead to dysregulated immune responses and chronic diseases later in life. Adults who grew up experiencing higher levels of family stress have been found to have higher rates of asthma, stroke, autoimmune diseases and depression. Lifetime stress may help explain why minorities have higher rates of health conditions such as rheumatoid arthritis and diabetes as well as a greater propensity to get severely ill with Covid-19.

Stress has also been found to dampen the immune response to vaccines. Adults who report higher levels of stress and loneliness produce fewer antibodies in response to flu vaccines. Young people with higher stress levels and lower levels of psychological well-being have also been found to generate a weaker antibody response to inoculations for hepatitis B and meningitis. Kindergarten-aged children with higher levels of the stress hormone cortisol in their saliva also generate weaker antibody responses to pneumonia shots.

Because stress weakens the immune system, it can also cause flare-ups of latent herpes viruses like Epstein-Barr and lead to recurring infections. It may also contribute to lingering Covid-19 symptoms that some patients experience.

A new Centers for Disease Control and Prevention study finds that Covid-19 patients with psychiatric conditions—primarily anxiety and depression—were 2.3 times as likely to remain sick 14 to 21 days after testing positive for the virus. Mental illness was a stronger predictor of delayed recovery than most health conditions, including hypertension and diabetes.

Lockdowns and school shutdowns not only increase stress and mental illness, but also make it harder to modulate stress through exercise and socializing. Reopening schools could turn out to be the best antidote to Covid-19.

Ms. Finley is a member of the Journal’s editorial board.

The harm from lost instruction outweighs the Covid-19 risks. Image: Thom Bridge/Independent Record via AP


Appeared in the August 12, 2020, print edition as '.'