A specific type of polio virus is spreading both in Rockland County, New York and neighboring areas, prompting the World Health Organization (WHO) to add the United States to a list of countries (opens in new tab) where similar polioviruses have been detected. The list includes about 30 countries in Europe, Asia and Africa, such as the United Kingdom, Israel, Yemen, Algeria and Niger.
The official addition of the US to this list was announced last week by the US Centers for Disease Control and Prevention (opens in new tab) (CDC) and the news raised questions about what happens next. Do people who received all their polio vaccine doses as children now need a booster? What should you do if you are not sure about your vaccination status, or if you are sure that you have not received the polio vaccination?
Crucially, there is no general recommendation for fully vaccinated people to seek out polio boosters.
“Certainly, at this time there are no national or local recommendations for people who are confident in their childhood vaccination series to need an extra booster,” said Dr. William Schaffner, a professor of medicine in the distribution of infectious diseases. at the Vanderbilt University School of Medicine in Tennessee. However, he noted that there may be certain circumstances – which we will describe below – in which it may be reasonable for a person to look for a booster.
Related: Who Made the Polio Vaccine?
For now, the primary concern of health officials is to vaccinate those who have not yet completed their polio vaccination series, Schaffner told Gadgetmasti.
“Polio vaccination is the safest and best way to combat this debilitating disease and it is imperative that people in these unvaccinated communities are immediately informed about polio vaccination,” Dr. José R. Romero, director of the CDC’s National Center for Immunization and Respiratory Disease, said in the CDC statement. “We cannot emphasize enough that polio is a dangerous disease for which there is no cure.”
Recommendations for basic vaccination against polio
Since 2000, the U.S. has only used the inactivated polio vaccine (IPV), an injection usually injected into the arm or leg that contains a “dead” polio virus that cannot cause disease, according to the United States. CDC (opens in new tab). Another type of polio vaccine, the oral polio vaccine (OPV), is equally effective, but its use was discontinued in the US because it contains live, but attenuated, polio virus, Gadgetmasti previously reported. these weakened viruses can be excreted in the feces of vaccinated people and, in rare cases, can evolve to behave like wild, naturally occurring polioviruses that can cause illness and possibly paralysis in unvaccinated people.
Because of this risk, the US now controls only the IPV, but “vaccine-derived” polioviruses can still potentially be imported from places where the OPV is used — which is exactly what happened during the current outbreak.
“It shows how vulnerable we are to imports — not just from polio viruses, but other viruses, germs from abroad,” Schaffner said.
To protect against polio, the CDC recommends American children receive four doses of the IPV, with one dose given at each of the following ages: 2 months old, 4 months old, between 6 and 18 months of age, and between 4 and 6 years old . The CDC also offers several “catch-up schedules” (opens in new tab) for children who start their vaccination course late or who are delayed between doses.
Adults who have never received a polio vaccine should receive three doses of the IPV. These individuals can get their first dose at any time, get the second dose one to two months later, and get the third dose six to 12 months after that, the CDC recommends. Adults who have only received one or two doses in the past should seek additional doses to reach the recommended three.
Most US residents complete their polio vaccine series in childhood and it is generally not recommended to get boosters later in life. “This is just a testimony to the very solid, lifelong protection you get from the polio vaccine,” Schaffner said.
The first polio vaccines became available in 1955 and since then the injections have been recommended as routine vaccinations. according to Verify (opens in new tab). An adult is considered fully vaccinated if they have received at least three doses of the IPV or the “trivalent” OPV (tOPV), meaning the OPV protects against all three types of poliovirus, P1, P2, and P3. Alternatively, an adult is fully vaccinated if they have received four doses of a combination of the IPV and the tOPV, according to the CDC (opens in new tab).
Two doses of the IPV provide at least 90% protection against paralytic polio, which can occur when the virus infiltrates the central nervous system and causes weakness or paralysis in the arms, legs, or both; this can lead to permanent disability and death. Three doses are at least 99% protective, according to the CDC.
Related: Africa declared free of wild polio virus
Who Needs a Polio Booster?
There are instances where fully vaccinated adults may consider a one-time polio booster.
For example, a booster would be recommended if you work in a lab or healthcare setting handling polio virus specimens, or if you are a health professional treating patients with polio or may come into close contact with people infected with the virus. You can also look for a booster if you are traveling to a country where the risk of exposure to polio is ‘greater’. For example, the wild polio virus is still circulating in Afghanistan and Pakistan, and long-term visitors should be given an IPV booster between four weeks and a year prior to their trip, according to the Global Polio Eradication Initiative (opens in new tab). (No similar recommendations have yet been extended to the US.)
So far, only one case of paralytic polio has been discovered in the US outbreak; this happened to an unvaccinated adult in Rockland County. Subsequently, poliovirus was detected in wastewater samples from Rockland County, Orange County, Sullivan County, New York City and Nassau County, reported the New York State Department of Health: (opens in new tab).
The health department currently recommends polio boosters for the following New Yorkers:
- Individuals who will or may have close contact with a person known or suspected to be infected with polio virus or with their family members or other close contacts.
- Healthcare providers who work in areas where polio virus has been detected and who may be handling samples that may contain polio viruses or treating patients who may have polio.
- Persons with occupational exposure to wastewater.
People in the affected countries who are weakened immune system might also consider a booster, Vincent Racaniello, a poliovirus expert at Columbia University Vagelos College of Physicians and Surgeons, said in a pronunciation (opens in new tab). And if you’re not sure how many doses of polio vaccine you’ve received, you can also consider getting a boost, he said.
There are some antibody tests for polio, but they are not recommended for assessing vaccination status because there is limited access to tests that screen for antibodies to all three types of polio virus, according to a 2017 Weekly report on morbidity and mortality (opens in new tab) issued by the CDA. “In the absence of testing for antibodies against all 3 serotypes, serological testing is no longer recommended to assess immunity,” the report states.
For U.S. residents outside of New York, the risk of polio exposure is likely similar to before the outbreak, Schaffner said — that is, negligible. However, people exposed to the virus in New York may be able to jump on a plane and carry polio to other places; for that reason, vaccination remains important no matter where you live, he said.
It is also important to note that “although IPV is very good at preventing the most serious potential effects of the disease, people who have received the vaccine can still carry polio and transmit it to others,” Dr. . Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health, told: CNN (opens in new tab).
Those vaccinated with the IPV can still pass the polio virus in their stool if they are ever exposed to the pathogen, even though they are protected from paralysis, according to the Pan American Health Organization (opens in new tab). That’s because the IPV is a very strong antibody response in the blood, but is not as effective at generating immunity in the gut.
Poliovirus usually spreads through contact with an infected person’s feces; less commonly, it can be transmitted through respiratory droplets released when an infected person sneezes or coughs, according to the CDC (opens in new tab). Washing your hands regularly with soap and water can help prevent the spread of the virus; notably, however, alcohol-based hand sanitizers do not kill polio viruses.
Most people who get polio develop no visible symptoms. About 25% develop flu-like symptoms, including sore throat, fever, fatigue, stomach pain, and nausea. A much smaller proportion of infected people develop serious symptoms, such as meningitis, an infection of the tissue surrounding the spinal cord and/or brain; or paralysis, which can lead to permanent disability and death.
Sometimes people who seem to be recovering from polio develop new muscle pain, weakness, or paralysis decades later; this is known as post-polio syndrome.
Originally published on Gadgetmasti.