Lessons from polio about the need to vaccinate kids against Covid-19

As pediatricians, epidemiologists, and professors of public health — as well as mothers — we are often asked if we recommend Covid vaccines for children. Those asking are often skeptical about the benefits and make the point that relatively few kids have died from Covid-19.

There’s also some institutional confusion: the American Academy of Pediatrics and the Centers for Disease Control and Prevention have urged families to get their children vaccinated, but some doctors now say the boosters may not be necessary. A new survey suggests that levels of vaccine hesitancy, even among primary care doctors, may be higher than expected: About one in ten physicians who responded to the survey said they did not believe the vaccines were safe and about 8% said they did not think the Covid-19 vaccines were important.

We strongly recommend that children receive both the initial Covid-19 vaccination series and any necessary boosters. We base that on lessons learned in dealing with polio.

In children who are not vaccinated against polio, 70% of poliovirus infections cause no symptoms at all. The 25% who develop symptoms have nothing more than a low-grade fever and a sore throat, a minor illness indistinguishable from a common cold. In this regard, polio is a lot like Covid-19, causing mostly symptoms that go unrecognized or are mild.

But some children get really sick from the poliovirus, and about 1% develop paralytic polio, usually occurring one to three days after what had seemed to be a minor illness has resolved. Children who develop paralysis require prolonged intensive respiratory therapy just to survive. They can also suffer from permanent disability or recover only to develop new muscle weakness or paralysis as adults.

Thanks to pioneering vaccine research begun in the late 1940s, four doses of polio vaccine between the ages of two months and six years now prevent infection and transmission of the virus, and provide protection over a lifetime.

There are certain parallels with Covid-19. Infection with SARS-CoV-2, the virus that causes Covid-19, is relatively benign for the vast majority of children who get it. A CDC survey indicated that, by February 2022, 75% of individuals under the age of 18 had had Covid-19 at least once.

Less than 2% of young people who develop Covid-19 experience a major acute illness, though rates of major illness are much higher among Black and Hispanic children. Children with Covid have higher rates of several severe health conditions after infection, including dangerous blood clots, inflammation of the heart muscle (myocarditis), acute kidney failure, and type 1 diabetes.

In addition, the CDC has identified more than 9,000 cases and 74 deaths due to a poorly understood multisystem inflammatory syndrome in children who have had Covid-19. Children can also develop long Covid and the fatigue, difficulty concentrating, and other neurological issues that go along with it, for which few if any treatments exist.

At the same time, existing Covid-19 vaccines are nowhere near as protective as the polio vaccine. The currently authorized Covid-19 vaccines do not protect people from infection in the context of an ever-changing virus and waning immunity from the current vaccine. They do, however, prevent Covid-19 from developing into a serious illness.

We are disturbed by Covid-19’s potential for long-term neurologic, cardiovascular, and metabolic consequences, which are worrisome enough to justify vaccinating kids against the disease, especially given the safety and effectiveness of the vaccines. Prior infection does not confer long-lasting immunity, so children need to be vaccinated unless they have medical contraindications.

The current Covid-19 vaccines do not provide lifetime immunity; boosters are needed to maintain that shield.

Given the advantages of vaccination, Covid-19 vaccination rates are generally low in children. As of mid-October, the CDC estimates that about 60% of 12- to 17-year-olds have received a primary Covid immunization series (meaning the first two doses of a Moderna or Pfizer mRNA vaccine or an initial dose of the J&J vaccine). The rates are even lower among younger children: 31.6% of children ages 5 to 11, 3.2% of children ages 2 to 4, and a mere 1.7% of children under age 2. The rates of booster shots in these age groups are much lower.

Those statistics translate into one thing: America’s children are becoming increasingly vulnerable to Covid.

As new variants of the virus keep emerging, it becomes even more important for parents to follow the advice of the CDC and American Academy of Pediatrics. For now, the most current information persuades us that pediatric vaccination is safe and effective against severe acute Covid-19 disease and its complications, in children as well as in adults.

It is too soon to know what the long-term consequences of Covid-19 infections in children will be. But lessons from polio and the past teach us that many viruses can have lifelong effects on health. That is why, in the case of Covid-19 as in so many others, we think that an ounce of prevention is worth a pound of cure.

Lynn R. Goldman is a pediatrician, epidemiologist, and dean of the Milken Institute School of Public Health at the George Washington University, where Amanda D. Castel is a pediatrician and professor of epidemiology.