A brief history of polio and why fears of a resurgence have health officials on high alert
Rosemary Rochford, Professor of Immunology and Microbiology, University of Colorado Anschutz Medical Campus
ASSOCIATED PRESS
Critical-care patients in the emergency polio ward at Haynes Memorial Hospital in Boston in August 1955.
Fears of polio gripped the U.S. in the mid-20th century. Parents were afraid to send their children to birthday parties, public pools or any place where children mingled. Children in wheelchairs served as a stark reminder of the ravages of the disease.
To prevent polio outbreaks, government officials used tactics now familiar in the era of COVID-19: They closed public spaces and shut down restaurants, pools and other gathering places.
In 1952, two years prior to the introduction of a trial polio vaccine, there were an estimated 58,000 cases of polio and 3,145 deaths due to polio in the U.S.. These cases included children who were paralyzed for life. But those numbers dropped dramatically following a widespread vaccination campaign against polio, beginning in 1955.
By the 1970s, there were fewer than 10 cases of paralysis due to polio in the U.S., and the polio virus was considered eliminated from the U.S. by 1979. Since then, collective fear of the virus has been mostly lost to history – many people alive today are lucky enough not to know someone who has experienced polio.
So when news broke in July 2022 that an unvaccinated adult man in New York had contracted polio – the first case in the U.S. since 2013 – and developed paralysis from the disease, it sent a ripple of fear throughout the public health community and raised the question of whether an old foe was making a comeback.
Polio – or poliomyelitis – the disease, is caused by the poliovirus, which is passed from person to person through the mouth. And while no one would knowingly ingest a virus, touching a contaminated object like a spoon or a glass or accidentally swallowing contaminated water can unknowingly lead to infection.
In August 2022, New York State Health Commissioner Mary Basset said that the state health department is “treating the single case of polio as just the tip of the iceberg of much greater potential spread.”
“Based on earlier polio outbreaks,” she added, “New Yorkers should know that for every one case of paralytic polio observed, there may be hundreds of other people infected.”
A single case of polio reflects a larger potential spread of the virus because most people infected either don’t show any symptoms or have a very mild illness with symptoms similar to the flu. But even without symptoms, an infected person is still excreting virus in their feces, which means they can be a source of infection to others.
The virus, which is very stable in the environment, is easily spread through surface contamination. For this reason, hand-washing is a critical prevention tool. Although many disinfecting agents, such as alcohol or diluted Lysol, fail to inactivate the virus, chlorine bleach does destroy it. This is why public health officials started chlorinating swimming pools decades ago in order to inactivate the polio virus.
Typically, the human body uses stomach acid to protect against ingested viruses. But poliovirus can survive stomach acid to travel to your gastrointestinal tract. There, the virus reproduces itself to establish an infection.
What is paralytic polio?
Unfortunately, one person out of about 200 people infected with poliovirus will develop paralysis. Scientists still don’t know why one person is susceptible to the paralytic disease while most are not.
In the small subset of people that get paralytic polio, the virus can attack the lower motor neurons found in the brain stem and spinal cord, which are important for controlling muscles. Infection of those neurons leads to the muscle paralysis that is characteristic of paralytic polio. The legs are typically affected – often on only one side of the body – and paralysis can range from mild to severe. Other muscle groups can also be affected.
In the worst cases of paralytic polio, the virus can damage the centers of the nervous system that control breathing. Respirators known as “iron lungs” were early medical devices that aided those with damaged respiratory muscles, helping them breathe until their muscles healed enough to work on their own. Patients could die when the paralysis was severe and sustained.
Levels of severity
Although polio can be devastating for those who contract the severe form of it, most people’s immune systems are well-equipped to combat it. When someone recovers from polio, researchers can detect poliovirus-fighting antibodies in the blood.
The decline in polio in the U.S. and globally is a direct result of the introduction of vaccines and the willingness of the public to accept them. In 1988, the World Health Organization, in partnership with Rotary International, the Centers for Disease Control and Prevention and other national governments, launched the Global Polio Eradication Initiative with the goal to wipe out polio worldwide, as is the case with smallpox.
Two types of polio vaccine are in use worldwide. The one used in the U.S. since 2000 is an injection made from inactivated poliovirus. Inactivation kills the virus and prevents it from spreading. Children in the U.S. get this shot at 2 months, 4 months and between 6 to 15 months of age, and it essentially provides lifelong protection from polio.
The second vaccine type, still in use in many parts of the world, is an attenuated – or weakened – form of the virus that is taken orally. In places where community transmission remains significant, like Pakistan, the oral vaccine is preferred because it prevents people from getting polio and also stops person-to-person transmission. In the U.S., where person-to-person transmission of the poliovirus has been virtually nonexistent for decades, the inactivated vaccine is preferred since the focus is on preventing disease in the vaccinated person and there’s less concern about spreading the virus.
But in extremely rare cases, the vaccine virus mutates after it’s been excreted in feces. And if immunization levels fall below a critical threshold – as is the case in some areas of the world – this poliovirus can cause disease. The recent New York polio case has been traced back to a mutated vaccine-derived poliovirus thought to be acquired overseas.
Most people in the U.S. are vaccinated through routine childhood vaccinations. Because immunity to polio following vaccination is lifelong, the CDC is not recommending booster vaccinations for the general population for people who completed the full series. However, the CDC does recommend that anyone who has not been vaccinated against polio virus get vaccinated, including adults.
In my office, I keep a painting of Dr. Jonas Salk, the virologist who developed the first polio vaccine. It serves as my reminder of the importance of biomedical research to help eliminate human suffering caused by infectious diseases.
___
Rosemary Rochford receives funding from National Institutes of Health.
___
A brief history of polio and why fears of a resurgence have health officials on high alert
Mario Tama // Getty Images
The current supply of monkeypox vaccine in the U.S. is limited, but the federal government has released a national vaccine strategy to be undertaken by the Food and Drug Administration, Centers for Disease Control and Prevention, National Institutes of Health, and the Administration for Strategic Preparedness and Response.
In advance of vaccines becoming more widely available, there are actions people can take to mitigate their risk of exposure and infection—actions that are also useful even between the first and second shot for those who have qualified for vaccination.
While monkeypox has not been classified as a sexually transmitted disease, it has been shown to be highly contagious in the context of close, intimate human contact. Therefore, exchanging contact information with any new partner to allow for sexual health follow-up, speaking openly with your partner about any monkeypox symptoms, and avoiding sharing things such as towels, sex toys, and toothbrushes are means by which people can proactively try to protect themselves from exposure. Close social situations, such as parties, raves, or nightclubs where patrons wear minimal clothing and where there is often direct bodily contact, also increase a person's risk.
Stacker compiled a list of frequently asked questions about the monkeypox vaccine from governments, scientific sources, and health experts. Stacker spoke with Dr. Wafaa El-Sadr, professor of epidemiology and medicine and chair of global health at Columbia University's Mailman School of Public Health, and Dr. Sandra A. Fryhofer, board-certified in internal medicine and chair of the American Medical Association's Board of Trustees, to gain their expert perspectives on the current state of vaccine dissemination and to discover what the near future holds for increased vaccine availability.
As of Aug. 30, 2022, there were 18,417 total confirmed monkeypox cases in the United States, according to the CDC.
The current supply of monkeypox vaccine in the U.S. is limited, but the federal government has released a national vaccine strategy to be undertaken by the Food and Drug Administration, Centers for Disease Control and Prevention, National Institutes of Health, and the Administration for Strategic Preparedness and Response.
In advance of vaccines becoming more widely available, there are actions people can take to mitigate their risk of exposure and infection—actions that are also useful even between the first and second shot for those who have qualified for vaccination.
While monkeypox has not been classified as a sexually transmitted disease, it has been shown to be highly contagious in the context of close, intimate human contact. Therefore, exchanging contact information with any new partner to allow for sexual health follow-up, speaking openly with your partner about any monkeypox symptoms, and avoiding sharing things such as towels, sex toys, and toothbrushes are means by which people can proactively try to protect themselves from exposure. Close social situations, such as parties, raves, or nightclubs where patrons wear minimal clothing and where there is often direct bodily contact, also increase a person's risk.
Stacker compiled a list of frequently asked questions about the monkeypox vaccine from governments, scientific sources, and health experts. Stacker spoke with Dr. Wafaa El-Sadr, professor of epidemiology and medicine and chair of global health at Columbia University's Mailman School of Public Health, and Dr. Sandra A. Fryhofer, board-certified in internal medicine and chair of the American Medical Association's Board of Trustees, to gain their expert perspectives on the current state of vaccine dissemination and to discover what the near future holds for increased vaccine availability.
As of Aug. 30, 2022, there were 18,417 total confirmed monkeypox cases in the United States, according to the CDC.
A brief history of polio and why fears of a resurgence have health officials on high alert
James Carbone/Newsday RM // Getty Images
The U.S. government has two stockpiled vaccines against monkeypox—Jynneos and ACAM2000. As of this writing, the Jynneos vaccine is the only one approved for public distribution.
Dr. Fryhofer clarified why ACAM2000 is not being administered. "It is an epidermal vaccine and that makes it more challenging to administer and it is riskier, and therefore, you need more trained personnel," she told Stacker. "Another thing to take into account is that for every dose of Jynneos, you need 500 of ACAM2000, so that also helps with not making it a preference."
James Carbone/Newsday RM // Getty Images
The U.S. government has two stockpiled vaccines against monkeypox—Jynneos and ACAM2000. As of this writing, the Jynneos vaccine is the only one approved for public distribution.
Dr. Fryhofer clarified why ACAM2000 is not being administered. "It is an epidermal vaccine and that makes it more challenging to administer and it is riskier, and therefore, you need more trained personnel," she told Stacker. "Another thing to take into account is that for every dose of Jynneos, you need 500 of ACAM2000, so that also helps with not making it a preference."
A brief history of polio and why fears of a resurgence have health officials on high alert
KENA BETANCUR/AFP // Getty Images
Each state has its own recommendations, but the CDC recommends vaccination for people who have been exposed to monkeypox and people who may be more likely to get monkeypox, and these include:
People who have been identified by public health officials as a contact of someone with monkeypox
People who know one of their sexual partners in the past 2 weeks has been diagnosed with monkeypox
People who had multiple sexual partners in the past 2 weeks in an area with known monkeypox
"The vaccine is being prioritized for post-exposure, and those with certain risk factors," explained Fryhofer, who added that the reason why not everyone is being called for vaccination is that there are not enough vaccines immediately available. Fryhofer also said that the vaccine may reduce symptoms but not prevent them.
KENA BETANCUR/AFP // Getty Images
Each state has its own recommendations, but the CDC recommends vaccination for people who have been exposed to monkeypox and people who may be more likely to get monkeypox, and these include:
People who have been identified by public health officials as a contact of someone with monkeypox
People who know one of their sexual partners in the past 2 weeks has been diagnosed with monkeypox
People who had multiple sexual partners in the past 2 weeks in an area with known monkeypox
"The vaccine is being prioritized for post-exposure, and those with certain risk factors," explained Fryhofer, who added that the reason why not everyone is being called for vaccination is that there are not enough vaccines immediately available. Fryhofer also said that the vaccine may reduce symptoms but not prevent them.
A brief history of polio and why fears of a resurgence have health officials on high alert
Mario Tama // Getty Images
If you are eligible, make an appointment in one of your city or state vaccination locations, either online or by phone. Use a simple Google search with the format "Appointment monkeypox vaccine (state, city, or county)" to find out how to get an appointment.
Dr. El-Sadr told Stacker, "We should try to make vaccines available to people who need them as soon as possible, and also assure people that this vaccine has been shown to be safe and effective."
Mario Tama // Getty Images
If you are eligible, make an appointment in one of your city or state vaccination locations, either online or by phone. Use a simple Google search with the format "Appointment monkeypox vaccine (state, city, or county)" to find out how to get an appointment.
Dr. El-Sadr told Stacker, "We should try to make vaccines available to people who need them as soon as possible, and also assure people that this vaccine has been shown to be safe and effective."
A brief history of polio and why fears of a resurgence have health officials on high alert
KENA BETANCUR/AFP // Getty Images
The New York City Health Department fact sheet about the Jynneos vaccine states that people who should avoid the vaccine include those who have had a severe allergic reaction to a prior dose or an ingredient in the vaccine, such as gentamicin, ciprofloxacin, or egg protein. But groups that might otherwise need to take caution on a novel vaccine—including pregnant or breastfeeding people, people with a heart condition or HIV, or people with a weakened immune system or skin condition—can get the vaccine.
KENA BETANCUR/AFP // Getty Images
The New York City Health Department fact sheet about the Jynneos vaccine states that people who should avoid the vaccine include those who have had a severe allergic reaction to a prior dose or an ingredient in the vaccine, such as gentamicin, ciprofloxacin, or egg protein. But groups that might otherwise need to take caution on a novel vaccine—including pregnant or breastfeeding people, people with a heart condition or HIV, or people with a weakened immune system or skin condition—can get the vaccine.
A brief history of polio and why fears of a resurgence have health officials on high alert
Liao Pan/China News Service // Getty Images
"I think it's important for people to get the vaccine if they are in danger," El-Sadr said. She went on to explain that the danger groups are quite specific: Individuals with close contact to someone diagnosed, because the vaccine may prevent them from getting the infection; people at high risk, such as men who have sex with men, as most of the infections are occurring within this group; and finally, people who are at risk of developing severe monkeypox, such as those living with HIV or AIDS.
"I think it's important for people to get the vaccine if they are in danger," El-Sadr said. She went on to explain that the danger groups are quite specific: Individuals with close contact to someone diagnosed, because the vaccine may prevent them from getting the infection; people at high risk, such as men who have sex with men, as most of the infections are occurring within this group; and finally, people who are at risk of developing severe monkeypox, such as those living with HIV or AIDS.
ACAM2000 is a single-dose vaccine, and it takes four weeks after vaccination for its immune protection to reach its maximum. However, it has the potential for more side effects and adverse events than Jynneos, and this is why it is not recommended for people with severely weakened immune systems and several other conditions.
ACAM2000 is a single-dose vaccine, and it takes four weeks after vaccination for its immune protection to reach its maximum. However, it has the potential for more side effects and adverse events than Jynneos, and this is why it is not recommended for people with severely weakened immune systems and several other conditions.
A brief history of polio and why fears of a resurgence have health officials on high alert
Paul Bersebach/MediaNews Group/Orange County Register // Getty Images
While side effects are a potential reality for any administered medication, El-Sadr explained that "Jynneos has well-tolerated effects—which means it causes few side effects, the most common one being pain where the vaccine was administered. So, only local side effects. It might also cause more general side effects, like itchiness, fatigue, or headache, but that is rare."
ACAM2000 has the potential for more side effects and adverse events than Jynneos. This is why it is not recommended for people with severely weakened immune systems and several other conditions. More about each vaccine's side effects can be found at the FDA website.
Paul Bersebach/MediaNews Group/Orange County Register // Getty Images
While side effects are a potential reality for any administered medication, El-Sadr explained that "Jynneos has well-tolerated effects—which means it causes few side effects, the most common one being pain where the vaccine was administered. So, only local side effects. It might also cause more general side effects, like itchiness, fatigue, or headache, but that is rare."
ACAM2000 has the potential for more side effects and adverse events than Jynneos. This is why it is not recommended for people with severely weakened immune systems and several other conditions. More about each vaccine's side effects can be found at the FDA website.
A brief history of polio and why fears of a resurgence have health officials on high alert
David Joles/Star Tribune // Getty Images
The vaccine cannot cause monkeypox or smallpox in the vaccinated individual or those near them. This is because the virus in the vaccine is weakened and cannot copy into human cells.
"The monkeypox vaccine is developed for smallpox as well as monkeypox," El-Sadr explained. "It essentially contains a type of pox that contains a virus from the same family as monkeypox and smallpox, but it's not able to multiply or replicate in a person."
David Joles/Star Tribune // Getty Images
The vaccine cannot cause monkeypox or smallpox in the vaccinated individual or those near them. This is because the virus in the vaccine is weakened and cannot copy into human cells.
"The monkeypox vaccine is developed for smallpox as well as monkeypox," El-Sadr explained. "It essentially contains a type of pox that contains a virus from the same family as monkeypox and smallpox, but it's not able to multiply or replicate in a person."
A brief history of polio and why fears of a resurgence have health officials on high alert
Karen Ducey // Getty Images
The Jynneos vaccine's maximum immunity is 14 days after the second dose. With ACAM2000, it takes four weeks after vaccination to be fully protected.
According to the American Medical Association, both vaccines are believed to be about 85% effective at preventing monkeypox, but to date, neither has been studied for post-exposure prevention. "We do not have information on vaccine effectiveness for monkeypox in this specific context," Dr. Caroline Schrodt, an expert from the CDC's Division of High-Consequence Pathogens and Pathology in Atlanta, told the AMA.
Karen Ducey // Getty Images
The Jynneos vaccine's maximum immunity is 14 days after the second dose. With ACAM2000, it takes four weeks after vaccination to be fully protected.
According to the American Medical Association, both vaccines are believed to be about 85% effective at preventing monkeypox, but to date, neither has been studied for post-exposure prevention. "We do not have information on vaccine effectiveness for monkeypox in this specific context," Dr. Caroline Schrodt, an expert from the CDC's Division of High-Consequence Pathogens and Pathology in Atlanta, told the AMA.
A brief history of polio and why fears of a resurgence have health officials on high alert
Sean Rayford // Getty Images
As Fryhofer explained, "these vaccines have been available for years—ACAM2000 since 2007 and JYNNEOS since 2019. There are no new vaccines already studied and available. We need to learn from our mistakes with COVID and educate the public about symptoms, what to look for and what to do, disposition [toward infection], and how to avoid monkeypox, so we can stop the spread."
"Also, we need to push the government to get more doses than [what] we have, because we have funding to stop the spread," Fryhofer added. "But we have to act quickly and improve the health of the nation. We could be really getting into another pandemic if monkeypox is spread everywhere around schools, health care facilities, and elder care facilities."
El-Sadr said there are differences and similarities between the two types of vaccines. "There are many different kinds of COVID vaccines," she pointed out. "We have two vaccines that are messengerRNA or MRNA—Pfizer and Moderna. The other is made from protein; this one contains a weakened form of the virus. Moderna and Pfizer don't contain the virus itself. The immune system will [instead] produce some portion of the virus that will generate protective antibodies against the virus."
As Fryhofer explained, "these vaccines have been available for years—ACAM2000 since 2007 and JYNNEOS since 2019. There are no new vaccines already studied and available. We need to learn from our mistakes with COVID and educate the public about symptoms, what to look for and what to do, disposition [toward infection], and how to avoid monkeypox, so we can stop the spread."
"Also, we need to push the government to get more doses than [what] we have, because we have funding to stop the spread," Fryhofer added. "But we have to act quickly and improve the health of the nation. We could be really getting into another pandemic if monkeypox is spread everywhere around schools, health care facilities, and elder care facilities."
El-Sadr said there are differences and similarities between the two types of vaccines. "There are many different kinds of COVID vaccines," she pointed out. "We have two vaccines that are messengerRNA or MRNA—Pfizer and Moderna. The other is made from protein; this one contains a weakened form of the virus. Moderna and Pfizer don't contain the virus itself. The immune system will [instead] produce some portion of the virus that will generate protective antibodies against the virus."
A brief history of polio and why fears of a resurgence have health officials on high alert
Spencer Platt // Getty Images
El-Sadr was firm: "No, you should not vaccinate if you have been diagnosed or suspected of having monkeypox." Her suggestion is to go and seek care "so that you can be examined and evaluated, and hopefully then the individual will be either diagnosed with monkeypox or not."
If you have had the infection already, El-Sadr's advice is to "isolate, call your close contacts to let them know, and you don't need to get vaccinated."
El-Sadr was firm: "No, you should not vaccinate if you have been diagnosed or suspected of having monkeypox." Her suggestion is to go and seek care "so that you can be examined and evaluated, and hopefully then the individual will be either diagnosed with monkeypox or not."
If you have had the infection already, El-Sadr's advice is to "isolate, call your close contacts to let them know, and you don't need to get vaccinated."
A brief history of polio and why fears of a resurgence have health officials on high alert
Smith Collection/Gado // Getty Images
According to the FDA, any conclusions as to whether any dosage or sequence of dosages beyond the presently approved two doses of Jynneos may provide adequate protection against monkeypox is still pending. For now, the only currently approved regimen is the two-dose regimen.
Â
Smith Collection/Gado // Getty Images
According to the FDA, any conclusions as to whether any dosage or sequence of dosages beyond the presently approved two doses of Jynneos may provide adequate protection against monkeypox is still pending. For now, the only currently approved regimen is the two-dose regimen.
Mario Tama // Getty Images