People who are unvaccinated or incompletely vaccinated against polio and living in New York should get the vaccine as soon as possible, the New York State Department of Health (NYSDOH) urged earlier this month.
Traces of the polio virus are showing up in NYC and upstate NY wastewater, but so far only one person has been detected with the virus.
Last month, it was revealed that an unvaccinated Rockland County man in his 20’s had sought medical attention after partial paralysis and was diagnosed with the disease. After investigating, upstate New York officials confirmed that wastewater samples from Rockland and Orange counties as far back as April showed the presence of the virus.
Last week, NYC officials said that the virus was found in sewage water.
The CDC issued a report on Tuesday, August 16, and said that this case was only the second instance of community transmission of polio in the US since 1979.
Health Commissioner Mary Bassett said there may be hundreds of other people who have been infected. “Based on earlier polio outbreaks, New Yorkers should know that for every one case of paralytic polio observed, there may be hundreds of other people infected,” Bassett said.
State health officials are urgently advising people who are unvaccinated to receive their shots as soon as possible.
In answer to the question, “Do I or my children need a booster?” – One kind of polio vaccine has been used in the US since the year 2000, the inactivated polio vaccine, or IPV. Two doses of the vaccine provide 90% protection against all three types of polio virus, while three doses show at least 99% immunity, according to the CDC. There is one lifetime booster option but it’s only recommended for adults at increased exposure risk.
In the US, the IPV vaccine, used since 2000, is administered during childhood in four separate doses: one dose at two months, one dose at four months, one dose between 6 and 18 months old, and a final dose between four and six. According to the CDC, most adults in the US were vaccinated as children.
Origin of the virus caught by the Rockland County person is not 100% clear, but the CDC does have clues.
The Rockland patient did not travel abroad. Detection of the VDPV2 (vaccine-derived polio virus type 2) in his stool samples means that he might have caught it from a person who received an oral polio vaccine that contained the type 2 polio virus. The use of that vaccine was stopped in 2000 as part of the standard immunization schedule in the US.
The CDC said that, “Genome sequence comparisons have identified a link to vaccine-related type 2 polioviruses recently detected in wastewater in Israel and the United Kingdom.”
What does this mean? It means the virus that is being found in wastewater is a strain related to the live virus in a vaccine that was discontinued in this country in 2000. The vaccine (OPV) is reportedly safe, but the weakened strain of the poliovirus in the OPV can spread among under-immunized populations.
In the words of the CDC website, “a vaccine-derived poliovirus (VDPV) is a strain related to the weakened live poliovirus contained in oral polio vaccine (OPV). If allowed to circulate in under- or unimmunized populations for long enough, or replicate in an immunodeficient individual, the weakened virus can revert to a form that causes illness and paralysis.”
The US has used an inactivated poliovirus vaccine (IPV) since 2000, and it protects against polio paralysis cause by any type of poliovirus, including the vaccine-derived strain (VDPV).
Only three cases of disease caused by VDPVs have been confirmed in the US since 2000, all in people who were not vaccinated against polio or had a weakened immune system.”These viruses and bacteria are out there, it’s just that we’re protected from disease because we’re getting vaccinated,” said Dr. Yvonne Maldonado, an infectious disease specialist with Stanford Health Care. “If people say, ‘Oh, they’re not around anymore so we’re not going to get vaccinated,’ we’re going to go back to the days when kids were routinely getting polio.”