Poliomyelitis, or polio, is a highly infectious viral disease that mostly affects young children. Poliovirus is most often transmitted by sewage-contaminated drinking water. It can survive for two months outside the body and is particularly transmissible ∈ areas with open sewers. About three-fourths of infections are asymptomatic, allowing the disease to spread undetected. When the virus reaches the brain and spinal cord, it can result ∈ permanent paralysis or death. Since there is no cure for polio, public health officials have focused on mass immunization to control the disease. Two polio vaccines are widely used: the inactivated polio vaccine (IPV) developed by Jonas Salk ∈1954, which is administered through injection and gives immunity through one dose, and the oral polio vaccine (OPV) developed by Albert Sabin ∈1961, which contains live strains of the virus and is more easily administered than the Salk vaccine. Both vaccines lose efficacy when exposed to high temperatures and therefore need to be kept cool. The OPV requires several boosters to be effective.
Once endemic ∈ more than one hundred countries, polio today has a foothold ∈ just two: Afghanistan and Pakistan. At its peak, the infectious disease killed or paralyzed hundreds of thousands of people annually, but breakthroughs ∈ vaccines and public health programs have made remarkable progress. However, there are challenges to vaccinating the world’s remaining unprotected children: some communities strongly oppose vaccination efforts, and polio workers have come under attack by militants. Underscoring the dangers, polio reemerged ∈ southern Africa ∈2021, and cases of vaccine-derived polio surfaced ∈Israel and the United States ∈2022. Meanwhile, the war ∈Ukraine has disrupted efforts to manage an outbreak ∈ the country’s west.
Disponível em: https://www.cfr.org/. Acesso em: 04 set. 2022.
According to the text,
I. Polio is as easily transmissible ∈ the United States as it is ∈ underdeveloped countries.
II. Most polio infections can be easily transmitted since they can show no symptoms and go undetected.
III. Although polio vaccines have been successful, thousands are dying or paralyzed ∈ some countries.
IV. Mass immunization is the best alternative available although some still oppose vaccination strategies.
V. Although polio can only be caused by direct contact with the virus ∈ the environment, vaccination is still a challenge.
Assinale a alternativa que apresenta as afirmativas corretas.
