21.3 Prevention and Treatment of Viral Infections

21.3 Prevention and Treatment of Viral Infections

  • This transmission electron micrograph shows the naked icosahedral capsid that is incorporated into the host DNA.
    • The oncogenic nature of the virus can lead to cancer.
  • There are a variety of diseases caused by Viruses in animals and humans, ranging from the common cold to potentially fatal illnesses.
    • These diseases can be treated with drugs or vaccines, but some viruses, such as HIV, can avoid the immune response and become resistant to drugs.
  • Viruses can cause a lot of illnesses in humans.
    • There is no evidence that vaccines cause disease or that they contribute to autism.
  • Live viral vaccines are designed to cause few symptoms in recipients while giving them protection against future infections.
    • The use of vaccines was a milestone in the disease of polio.
    • The incidence of the disease was reduced by mass immunization campaigns in the 1950s and 1960s, which caused a great amount of fear in the general population.
  • The success of the vaccine paved the way for routine immunization against other diseases.
  • The growth of the virus in the laboratory can be aided by the introduction of new cells or temperatures that cause a change in the genomes of the virus.
    • The immune response to the attenuated viruses can be developed in time to prevent major disease.
    • The vaccine can cause disease in the host and then be spread to other humans in an epidemic if it undergoes back mutations.
  • This type of scenario happened in Nigeria in 2007, where there was an epidemic of the disease.
  • Some vaccines are in continuous development because they have a high rate of change compared to other viruses and normal host cells.
  • The same vaccine is used year after year for the diseases that cause the childhood diseases.
  • Vaccinations are designed to boost immunity.
  • They can understand more about the Spanish flu.
  • Vaccines can be used to treat an active viral infection.
    • By giving the vaccine, immunity is boosted without adding more disease-causing virus.
    • The progression of the disease from the time of the bite to the time it enters the central nervous system can be two weeks or longer.
    • It is enough time for people who suspect they have been bitten by a sick animal to get a vaccine.
    • The potentially fatal neurological consequences of the disease are averted, and the individual only has to recover from the bite.
    • One of the fastest and most deadly viruses on Earth is being treated with this approach.
    • Humans can die from this disease within two weeks.
    • There is hope that people who are affected by the virus will be able to control it using new vaccines that boost the immune response.
  • Antiviral drugs are used to treat viral infections.
    • It is difficult to block the activities of viruses without damaging the host.
    • We have some effective antiviral drugs, such as those used to treat HIV and flu.
    • Some drugs can be used to control and reduce symptoms for a wide variety of viral diseases.
    • These drugs can block the actions of one or more of the virus's genes.
    • It is important to note that the targets are not present in a healthy cell.
    • In this way, there is no harm to the host.
  • Antivirals can be used to treat genital herpes.
    • The number and duration of episodes of active viral disease can be reduced with the use of drugs such as acyclovir.
    • The drug can make the symptoms of the disease more manageable because the virus remains in the nervous tissue for life.
    • The duration of "flu" symptoms can be reduced by one or two days, but the drug does not prevent symptoms entirely.
    • The antiviral drug tamiflu works by blocking the neuraminidase that allows new infections to leave their cells.
  • Ribavirin has been used to treat a variety of viral infections, although its mechanism of action is not clear.
  • The neuraminidase prevents the virus from detaching from the host cell.
  • The treatment of the retroviruses HIV, which causes a disease that is usually fatal within 10 to 12 years after infection, has been the most successful use of antivirals.
    • Anti-HIV drugs have been able to control the replication of the disease, which means that people who receive these drugs live longer than those who don't.
  • The fusion of the HIV viral envelope with the host cell is one of the drugs that have been developed.
  • The CD4 receptor of an immune cell is a target for the HIV virus.
    • The viral contents are released into the cell, where they can be incorporated into the host genome.
  • It is more difficult for the virus to develop resistance to multiple drugs at the same time if it is attacked at different stages of its replicative cycle.
    • Even with the use of combination HAART therapy, there is concern that the virus will develop resistance over time.
    • New anti-HIV drugs are being developed with the hope of continuing the battle against the deadly virus.