Why Did Polio Return To London And New York

Today, wild poliovirus is endemic only in pockets of Afghanistan and Pakistan. The type detected in London and New York is a vaccine-derived strain, a rare mutation derived from the oral polio vaccine. Unlike the vaccine used in Western countries, which is based on an inactivated virus, the oral vaccine contains a weakened strain of the live virus. It is still used in poor countries for various reasons. First, it is cheaper and easier to manage. Second, a person who receives the oral vaccine can pass on immunity through “passive inoculation”: he sheds the weakened virus in his stool for a few weeks after vaccination. If an unvaccinated person ingests particles of the virus (which is common in places with poor sanitation) and that person is vaccinated. But this secondary benefit comes with a great deal of risk. If the vaccine-derived virus continues to circulate among unvaccinated people, it gradually mutates into a harmful form that can cause paralysis in about one in a thousand infected people. This mutation process usually takes about a year. Vaccine-derived polio outbreaks are more common in Africa, due to inadequate vaccination rates. Occasional outbreaks have also occurred in areas of Asia and the eastern Mediterranean. It is from one of these three areas that the poliovirus circulating in London and New York was probably introduced. Polio is now spreading in the two cities when people ingest particles from the feces of an infected person. If someone who is infected does not wash their hands after using the toilet, or a caregiver does not wash their hands after changing an infected child’s diaper, they can spread the virus by touching food or other objects (such as toys that other children put in their mouths). and through handshakes. Both the oral and the inactivated vaccine prevent paralysis. But they are not particularly good at preventing this kind of transmission. Inactivated jab is especially bad at this. The oral vaccine’s protection against transmission is strong at first (so good for outbreaks) but is relatively short-lived. America and Europe stopped using it about twenty years ago. This means that some vaccinated people in London and New York may be part of polio transmission chains, although unvaccinated people are much more likely to transmit the disease because they shed the virus for longer. In London, the boroughs where the sewage samples have the most polio virus are those with some of the lowest polio vaccination rates. The concern now is that polio will paralyze some unvaccinated children if it continues to circulate at a high rate. The young man who became paralyzed in America had not been vaccinated. Many infections go unnoticed because paralysis is so rare. About 70% of unvaccinated people would have no symptoms and the rest would have only mild flu-like symptoms. Vaccination campaigns, including boosters, have recently begun in London and some New York counties. Doctors in New York have been asked to contact parents of children who have not been fully vaccinated. In 2020 the World Health Organization approved a new form of the oral polio vaccine. It contains a polio virus that has been genetically engineered to prevent it from becoming harmful, but still has the secondary benefit of passive vaccination. The new vaccine is now being used for mass vaccination campaigns in African and Asian countries with polio epidemics. As its supply grows, it will completely replace the older oral vaccine. This will prevent further emergence of vaccine-derived strains. But those already rolling out in New York and London, two of the world’s busiest travel hubs, may be spreading widely.■ More than The economist explains:What’s at stake at Ukraine’s Zaporizhia nuclear plant Who is William Ruto?What is recession?

title: “Why Did Polio Return To London And New York Klmat” ShowToc: true date: “2022-12-04” author: “Samuel Schexnayder”

Today, wild poliovirus is endemic only in pockets of Afghanistan and Pakistan. The type detected in London and New York is a vaccine-derived strain, a rare mutation derived from the oral polio vaccine. Unlike the vaccine used in Western countries, which is based on an inactivated virus, the oral vaccine contains a weakened strain of the live virus. It is still used in poor countries for various reasons. First, it is cheaper and easier to manage. Second, a person who receives the oral vaccine can pass on immunity through “passive inoculation”: he sheds the weakened virus in his stool for a few weeks after vaccination. If an unvaccinated person ingests particles of the virus (which is common in places with poor sanitation) and that person is vaccinated. But this secondary benefit comes with a great deal of risk. If the vaccine-derived virus continues to circulate among unvaccinated people, it gradually mutates into a harmful form that can cause paralysis in about one in a thousand infected people. This mutation process usually takes about a year. Vaccine-derived polio outbreaks are more common in Africa, due to inadequate vaccination rates. Occasional outbreaks have also occurred in areas of Asia and the eastern Mediterranean. It is from one of these three areas that the poliovirus circulating in London and New York was probably introduced. Polio is now spreading in the two cities when people ingest particles from the feces of an infected person. If someone who is infected does not wash their hands after using the toilet, or a caregiver does not wash their hands after changing an infected child’s diaper, they can spread the virus by touching food or other objects (such as toys that other children put in their mouths). and through handshakes. Both the oral and the inactivated vaccine prevent paralysis. But they are not particularly good at preventing this kind of transmission. Inactivated jab is especially bad at this. The oral vaccine’s protection against transmission is strong at first (so good for outbreaks) but is relatively short-lived. America and Europe stopped using it about twenty years ago. This means that some vaccinated people in London and New York may be part of polio transmission chains, although unvaccinated people are much more likely to transmit the disease because they shed the virus for longer. In London, the boroughs where the sewage samples have the most polio virus are those with some of the lowest polio vaccination rates. The concern now is that polio will paralyze some unvaccinated children if it continues to circulate at a high rate. The young man who became paralyzed in America had not been vaccinated. Many infections go unnoticed because paralysis is so rare. About 70% of unvaccinated people would have no symptoms and the rest would have only mild flu-like symptoms. Vaccination campaigns, including boosters, have recently begun in London and some New York counties. Doctors in New York have been asked to contact parents of children who have not been fully vaccinated. In 2020 the World Health Organization approved a new form of the oral polio vaccine. It contains a polio virus that has been genetically engineered to prevent it from becoming harmful, but still has the secondary benefit of passive vaccination. The new vaccine is now being used for mass vaccination campaigns in African and Asian countries with polio epidemics. As its supply grows, it will completely replace the older oral vaccine. This will prevent further emergence of vaccine-derived strains. But those already rolling out in New York and London, two of the world’s busiest travel hubs, may be spreading widely.■ More than The economist explains:What’s at stake at Ukraine’s Zaporizhia nuclear plant Who is William Ruto?What is recession?

title: “Why Did Polio Return To London And New York Klmat” ShowToc: true date: “2022-10-26” author: “Marquitta Capito”

Today, wild poliovirus is endemic only in pockets of Afghanistan and Pakistan. The type detected in London and New York is a vaccine-derived strain, a rare mutation derived from the oral polio vaccine. Unlike the vaccine used in Western countries, which is based on an inactivated virus, the oral vaccine contains a weakened strain of the live virus. It is still used in poor countries for various reasons. First, it is cheaper and easier to manage. Second, a person who receives the oral vaccine can pass on immunity through “passive inoculation”: he sheds the weakened virus in his stool for a few weeks after vaccination. If an unvaccinated person ingests particles of the virus (which is common in places with poor sanitation) and that person is vaccinated. But this secondary benefit comes with a great deal of risk. If the vaccine-derived virus continues to circulate among unvaccinated people, it gradually mutates into a harmful form that can cause paralysis in about one in a thousand infected people. This mutation process usually takes about a year. Vaccine-derived polio outbreaks are more common in Africa, due to inadequate vaccination rates. Occasional outbreaks have also occurred in areas of Asia and the eastern Mediterranean. It is from one of these three areas that the poliovirus circulating in London and New York was probably introduced. Polio is now spreading in the two cities when people ingest particles from the feces of an infected person. If someone who is infected does not wash their hands after using the toilet, or a caregiver does not wash their hands after changing an infected child’s diaper, they can spread the virus by touching food or other objects (such as toys that other children put in their mouths). and through handshakes. Both the oral and the inactivated vaccine prevent paralysis. But they are not particularly good at preventing this kind of transmission. Inactivated jab is especially bad at this. The oral vaccine’s protection against transmission is strong at first (so good for outbreaks) but is relatively short-lived. America and Europe stopped using it about twenty years ago. This means that some vaccinated people in London and New York may be part of polio transmission chains, although unvaccinated people are much more likely to transmit the disease because they shed the virus for longer. In London, the boroughs where the sewage samples have the most polio virus are those with some of the lowest polio vaccination rates. The concern now is that polio will paralyze some unvaccinated children if it continues to circulate at a high rate. The young man who became paralyzed in America had not been vaccinated. Many infections go unnoticed because paralysis is so rare. About 70% of unvaccinated people would have no symptoms and the rest would have only mild flu-like symptoms. Vaccination campaigns, including boosters, have recently begun in London and some New York counties. Doctors in New York have been asked to contact parents of children who have not been fully vaccinated. In 2020 the World Health Organization approved a new form of the oral polio vaccine. It contains a polio virus that has been genetically engineered to prevent it from becoming harmful, but still has the secondary benefit of passive vaccination. The new vaccine is now being used for mass vaccination campaigns in African and Asian countries with polio epidemics. As its supply grows, it will completely replace the older oral vaccine. This will prevent further emergence of vaccine-derived strains. But those already rolling out in New York and London, two of the world’s busiest travel hubs, may be spreading widely.■ More than The economist explains:What’s at stake at Ukraine’s Zaporizhia nuclear plant Who is William Ruto?What is recession?

title: “Why Did Polio Return To London And New York Klmat” ShowToc: true date: “2022-11-29” author: “Marianela Apodaca”

Today, wild poliovirus is endemic only in pockets of Afghanistan and Pakistan. The type detected in London and New York is a vaccine-derived strain, a rare mutation derived from the oral polio vaccine. Unlike the vaccine used in Western countries, which is based on an inactivated virus, the oral vaccine contains a weakened strain of the live virus. It is still used in poor countries for various reasons. First, it is cheaper and easier to manage. Second, a person who receives the oral vaccine can pass on immunity through “passive inoculation”: he sheds the weakened virus in his stool for a few weeks after vaccination. If an unvaccinated person ingests particles of the virus (which is common in places with poor sanitation) and that person is vaccinated. But this secondary benefit comes with a great deal of risk. If the vaccine-derived virus continues to circulate among unvaccinated people, it gradually mutates into a harmful form that can cause paralysis in about one in a thousand infected people. This mutation process usually takes about a year. Vaccine-derived polio outbreaks are more common in Africa, due to inadequate vaccination rates. Occasional outbreaks have also occurred in areas of Asia and the eastern Mediterranean. It is from one of these three areas that the poliovirus circulating in London and New York was probably introduced. Polio is now spreading in the two cities when people ingest particles from the feces of an infected person. If someone who is infected does not wash their hands after using the toilet, or a caregiver does not wash their hands after changing an infected child’s diaper, they can spread the virus by touching food or other objects (such as toys that other children put in their mouths). and through handshakes. Both the oral and the inactivated vaccine prevent paralysis. But they are not particularly good at preventing this kind of transmission. Inactivated jab is especially bad at this. The oral vaccine’s protection against transmission is strong at first (so good for outbreaks) but is relatively short-lived. America and Europe stopped using it about twenty years ago. This means that some vaccinated people in London and New York may be part of polio transmission chains, although unvaccinated people are much more likely to transmit the disease because they shed the virus for longer. In London, the boroughs where the sewage samples have the most polio virus are those with some of the lowest polio vaccination rates. The concern now is that polio will paralyze some unvaccinated children if it continues to circulate at a high rate. The young man who became paralyzed in America had not been vaccinated. Many infections go unnoticed because paralysis is so rare. About 70% of unvaccinated people would have no symptoms and the rest would have only mild flu-like symptoms. Vaccination campaigns, including boosters, have recently begun in London and some New York counties. Doctors in New York have been asked to contact parents of children who have not been fully vaccinated. In 2020 the World Health Organization approved a new form of the oral polio vaccine. It contains a polio virus that has been genetically engineered to prevent it from becoming harmful, but still has the secondary benefit of passive vaccination. The new vaccine is now being used for mass vaccination campaigns in African and Asian countries with polio epidemics. As its supply grows, it will completely replace the older oral vaccine. This will prevent further emergence of vaccine-derived strains. But those already rolling out in New York and London, two of the world’s busiest travel hubs, may be spreading widely.■ More than The economist explains:What’s at stake at Ukraine’s Zaporizhia nuclear plant Who is William Ruto?What is recession?