New York health officials have discovered a case of polio, the first case of the dangerous viral disease in the United States in years.
The case was discovered in a Rockland County struggling in 2019 with an explosive measles outbreak fueled by parts of the community with low vaccination rates. Health officials in Rockland, neighboring New York City, and the state are now urging unvaccinated residents, especially children, to get vaccinated, and those who are vaccinated, but at high risk, to get a vaccine. get boost.
“Many of you may be too young to remember polio, but growing up, this disease caused fear in families, including mine,” Rockland County Executive Ed Day said in a statement. “The fact that it’s still about decades after the vaccine was created shows how unforgiving it is. Do the right thing for your child and the greater good of your community and get your child vaccinated now.”
(Update, 6:33 PM ET: Details on the polio case are scarce for now, but officials in Rockland County said the case involved a young adult, who had not been vaccinated and had not traveled abroad recently. The person is no longer contagious, but the person did develop paralysis from their infection. It’s unclear how the person became infected, and health officials are still investigating whether others were exposed or infected.) According to the New York State Health Department, a person was found to be infected with a vaccine-derived poliovirus type 2 (VDPV2), also known as revertant. . polio Sabin type 2 virus. This is a similar type of polio virus that has been detected in sewer samples in London in recent months.
Vaccine-derived polio strains arise from oral polio vaccines that use attenuated (attenuated) polioviruses. These types of polio vaccines are no longer used in the US and many other high-income countries where polio is no longer an imminent threat. Instead, the US and other countries use inactivated vaccines. The two vaccines have their own pros and cons.
How this happens?
Oral polio vaccines are relatively inexpensive and highly effective in preventing paralytic polio. And they can also prevent transmission. Because the vaccine contains an attenuated virus that can still replicate in the gut, they can generate strong immune responses in the gut that prevent wild polio virus from multiplying there in the event of a future infection. This means that in areas where wild polio is still a threat, the vaccine could prevent vaccinated people from becoming asymptomatic virus vectors.
The downside is that because the attenuated vaccine virus can replicate in the gut, vaccinated people can shed the vaccine virus, which can spread if conditions are right, mutate and regain the ability to cause disease.
Here’s how it happens: Polioviruses are transmitted by the oral-oral or fecal-oral route, meaning they spread because of poor hygiene – especially unwashed hands after using the bathroom and sharing saliva directly – or unsanitary conditions, such as food and drinking water are contaminated with feces. In the event that an oral vaccine is used in an environment of poor hygiene or unsanitary conditions, plus low vaccination rates, the vaccine virus can spread from unvaccinated person to unvaccinated person, picking up mutations at the same time, until it is able to cause disease again. At the moment it is called a VDPV.
In contrast, the inactivated vaccines use viruses that cannot reproduce. Thus, they do not run the risk of generating and spreading infectious viruses. But they’re more expensive — prohibitively expensive for some countries — and they don’t produce strong immune responses in the gut, which could allow wild polio virus to multiply and spread there.
Finding a VDPD in the US suggests the virus “may have originated in a location outside the US where” [oral polio vaccine] is administered because revertant strains cannot arise from inactivated vaccines,” the New York State Department of Health said in a statement Thursday.
The health department further warned that polio is highly contagious and that a person can spread the virus even if they have no symptoms. But when they have symptoms, they can feel the flu, with fatigue, fever, headache, stiffness, muscle aches and vomiting. These can appear up to 30 days after infection, during which time an infected person can pass the virus on to others.
As Ars has previously reported, most people infected with polio virus will have no symptoms, but about a quarter will develop those flu-like symptoms. In an estimated 1 to 5 in 1,000, the virus can attack the central nervous system, leading to more severe symptoms, including tingling in the legs and arms, meningitis and paralysis. The Centers for Disease Control and Prevention estimate that about 1 in 200 people infected with poliovirus will develop paralysis. And about 2 to 10 percent of people with paralytic polio will die because the paralysis will affect their ability to breathe.
For anyone who survives an infection, no matter how mild, an estimated 25 to 40 percent will develop post-polio syndrome, which can cause pain, weakness and paralysis 15 to 40 years after the initial infection.
With the introduction of vaccines in 1955, the incidence of polio in the US has been drastically reduced. The last case of polio from the US occurred in 1979. Occasional cases of travel and imported vaccines have surfaced since then. The New York Department of Health reports that the last time the CDC identified a VDPV in the US was in 2013.
New York health officials are now putting an emphasis on vaccination, and Rockland County will host a polio vaccination clinic starting Friday, July 22.
“Vaccines have protected our health from viruses old and new for decades,” said Ashwin Vasan, New York City’s health commissioner. “The fact is, the urgency of safe and effective vaccines has always been there, and we need New Yorkers to protect themselves from completely preventable viruses like polio.”