Polio Resurfaces: What Marylanders Need To Know

MARYLAND — Confirmation of the nation's first polio case in nearly a decade and the discovery of the poliovirus in New York City wastewater last week are fueling concerns in Maryland and nationwide about a return of the crippling childhood illness eradicated by vaccines 30 years ago.

As long as parents follow recommended vaccine schedules, they should be fine, health officials say. Although it’s contagious and is spread through person-to-person contact, poliovirus is not as transmissible as COVID-19.

The U.S. Centers for Disease Control and Prevention says a full round of childhood polio vaccinations between 2 months old and 6 years old is at least 99 percent effective.

Polio vaccinations are required for kids to start school in all 50 states and the District of Columbia. Several states allow medical, religious and philosophical exemptions to vaccinations, including those against polio.

Students generally have to comply with the immunization schedule by Sept. 1 if they want to attend school this fall. Those with a current religious exemption can be grandfathered in and keep it.

Lower Anti-Vax Sentiment For Polio

In Maryland, about 90.1 percent of kindergarteners in the 2020-21 school year were vaccinated against polio, according to the latest data from the CDC.

The CDC says nearly 93 percent of U.S. children have received the recommended three doses of polio vaccine by the time they reach 24 months — a higher rate of compliance than for other recommended vaccinations at that age, including measles, mumps and rubella and Hepatitis B, both 91 percent; chickenpox, 91 percent; pneumococcal conjugate vaccine and diphtheria, tetanus, pertussis, both 81 percent; haemophilus influenzae type b (Hib), 80 percent; combined seven-vaccine series, 68 percent.

The vaccination rate in Rockland County, New York, where the case of polio was confirmed, was only about 60 percent of all 2-year-olds as of Aug. 1. The vaccination rate in nearby Orange County is even lower, at 59 percent. Putnam and Westchester counties, which border Rockland, have vaccination rates of 78 percent and 76 percent, respectively, according to the New York Department of Health data.

Data are collected at the beginning of the school year, by which time vaccines are due. The numbers above are the most recent made available by DPH, in May 2022. As the year progresses, immunization rates may increase as additional children receive required immunizations. Additionally, the student body is dynamic and as students arrive and leave school, the immunization rates are impacted. The values for schools with fewer than 30 enrolled kindergarteners are left blank.

Polio Spreads Silently

About 3 in 4 people infected with the poliovirus don’t show any symptoms at all, allowing it to spread quickly among unvaccinated populations. That has raised alarm among CDC officials.

Dr. José Romero, director of the CDC's National Center for Immunization and Respiratory Diseases, told CNN last week that the confirmed New York case could be “just the very, very tip of the iceberg.”

He’s worried there are more people infected with and shedding poliovirus. “The spread is always a possibility because the spread is going to be silent,” he said.

What Are The Symptoms?

When people do show symptoms of poliovirus, they can be easily confused with other childhood illnesses. In most people, these symptoms that include sore throat, fever, fatigue, nausea, headache and stomach pain go away in two or five days, according to the CDC.
A smaller number of people with poliovirus will develop more serious symptoms affecting the brain and spinal cord, including meningitis and paralysis, the latter the most serious. Only about 1 in 200 people become paralyzed, and a few of them die because they can’t breathe, according to the CDC.

Vaccines Changed Everything

Parents rightly feared polio in the post-World War II years, when more than 35,000 people a year were disabled by polio. Before the 1955 vaccination campaign, towns practiced social distancing — closing city pools, swimming holes, schools, churches and other community gathering places, according to History.com.

Fear reached a panic level in San Angelo, California, where a series of polio deaths and a surge in polio infections prompted the military to airlift medical equipment into the area, and soon spread across the nation, according to History.com.

“Some motorists who had to stop for gas in San Angelo would not fill up their deflated tires,” the site said, “afraid they’d bring home air containing the infectious virus.”

By the 1960s, the number of polio cases fell to less than 100 a year. By the 1970s, there were fewer than 10 a year. Now, it is considered eliminated in the United States, but the CDC said the virus has been brought into the country by travelers with polio.

That happened in 1993, according to the CDC. The Rockland County polio case is vaccine-derived, the first such case since 2013.

How Long Are Vaccines Effective?

Most U.S. adults received polio vaccinations as children, so it’s not part of routine adult vaccinations. They shouldn’t need to get a booster, according to the CDC.

However, adults who are fully vaccinated but at increased risk of coming into contact with poliovirus — for example, those who travel to countries with low vaccination rates and those exposed to it in laboratory or health care settings — may get one lifetime booster, according to the CDC.

Adults who didn’t complete any or all of the recommended series of polio vaccines should either start or complete the series.

Right now, there are no recommendations for boosters for those who are fully vaccinated, or that childhood immunization schedules should be changed to accommodate earlier or additional doses, doctors at Weill Cornell Medicine wrote in n email to patients, The New York Times reported.

Patch editor Rich Kirby contributed to this article.