Polio threat virtually nonexistent to vaccinated people in Bay Area – San Francisco Chronicle

Despite concern over a case of polio being found in New York state in July, Bay Area infectious disease experts say the risk to the vaccinated public is virtually nonexistent — although the fact that any case at all popped up underscores the need to make sure people, particularly children, have had their shots.

“I’d say there is mild to moderate concern,” said Dr. Peter Chin-Hong, an infectious disease expert with UCSF, but “it all depends on whether or not your kids have been vaccinated or you’ve been vaccinated.”

He said that in the larger scheme, cases being detected elsewhere aren’t a worry because of very high vaccination rates in the U.S. — most children are inoculated at an early age — which means the virus hits a wall of immunity and is almost always unable to spread.

Still, there is reason to be vigilant. The New York Times reported that one case of polio was confirmed in a 20-year-old man in Rockland County who is part of an ultra-Orthodox Jewish community. The disease has since been detected in New York City wastewater, setting off fresh concerns.

Some Orthodox communities forgo vaccination, meaning that “it’s not unforeseen at all” that a case could happen, said Dr. George Rutherford, an infectious disease expert at UCSF. The Rockland County infection was one such case, according to the CDC.

However, Rutherford echoed Chin-Hong in noting that the high rates of vaccination in California and the rest of the country mean “the chances of somebody acquiring polio here unless they’re part of one of these unvaccinated communities is zero.”

He noted that polio shots contain an inactive piece of virus and cannot result in vaccine-derived polio. Oral polio vaccinations are cheap and can be easily administered, which is especially important in poor nations with weak health systems.

The virus typically spreads through fecal to oral transmission, meaning children are typically at a higher risk of contracting it. It can result in paralysis and other long-term issues such as muscle weakness, and can be fatal when it affects muscles involved in breathing.

Officials are alarmed about this latest detection of the virus because about 1 in every 200 cases of polio results in paralysis, said Dr. John Swartzberg, an infectious disease expert at the UC Berkeley School of Public Health. It’s especially worrisome that the virus has been detected in New York City wastewater, which means it’s circulating there, he said.

He put much of the blame for the virus reappearing on the anti-vaccination movement, which has gained popularity during the COVID pandemic.

“We wouldn’t have seen this young adult in New York who’s now paralyzed for the rest of his life if the anti-vax movement hadn’t directly motivated the wrong thinking” around immunization, he said.

Swartzberg recalled lining up to get the vaccine as a child in the 1950s, which at the time seemed like a miracle to him.

“It’s unconscionable that we’ve allowed this to happen,” he said. “People just don’t remember and weren’t alive during the ’50s when every family was touched with polio, including my own.”

While the newer mRNA vaccine technology used in COVID-19 vaccines has given some vaccine skeptics pause, Chin-Hong said the polio vaccine has proved safe and effective for decades. “You have to disentangle a new vaccine from this,” he said.

Chin-Hong said infected people can be asymptomatic, and with the amount of travel between the Bay Area and New York “it’s an exclamation point next to vaccination.”

The coronavirus era, he added, has amplified that exclamation point.

He said the pandemic stay-at-home orders in the Bay Area and elsewhere have probably delayed some children getting their polio shots. He’s also worried that a “generalized hesitancy over (COVID-19) vaccines … has spread to other vaccines.” And although California has a strong mandate for children to be vaccinated against polio to attend school, some homeschooled students may have lagged in getting their shots, Chin-Hong said.

He and Swartzberg emphasized that even given those concerns, the risk in California is extremely low.

“If you’re fully vaccinated, the vaccine works so well that you don’t need to worry no matter what age you are,” Swartzberg said. “For the general public who is fully vaccinated, there is zero worry.”

Chase DiFeliciantonio is a San Francisco Chronicle staff writer. Email: [email protected] Twitter: @ChaseDiFelice