What is Smallpox?
Smallpox is a highly contagious and deadly infectious disease caused by the variola virus. It is characterized by fever, body aches, and a distinctive pustular rash. Smallpox has been eradicated since 1980, thanks to a successful global vaccination campaign led by the World Health Organization (WHO).Why is Smallpox Still Relevant?
Despite its eradication, smallpox remains relevant due to
bioterrorism concerns. The variola virus is preserved in two high-security laboratories, one in Russia and one in the United States. The potential use of smallpox as a bioweapon necessitates ongoing research and preparedness strategies.
What Treatments Have Been Approved for Smallpox?
Although smallpox has been eradicated, the U.S. Food and Drug Administration (FDA) has approved treatments for potential outbreaks. The antiviral
tecovirimat (TPOXX) was approved in 2018 as the first drug specifically for smallpox treatment. Tecovirimat works by inhibiting the activity of a viral protein needed for viral replication.
How Does Tecovirimat Work?
Tecovirimat targets the
VP37 protein, an essential component of the variola virus envelope. By inhibiting this protein, tecovirimat prevents the virus from spreading to other cells, effectively halting the progression of the disease in the host.
Are There Other Approved Medications?
In addition to tecovirimat,
cidofovir and its derivative brincidofovir have shown promise against orthopoxviruses in laboratory studies. While not specifically approved for smallpox, these drugs have been used off-label for
monkeypox and other related infections.
What Vaccines are Available for Smallpox?
ACAM2000 is the current smallpox vaccine approved by the FDA. It is a live, attenuated vaccine derived from the
vaccinia virus, which is related to but less virulent than the variola virus. The vaccine is stored in the Strategic National Stockpile for emergency use.
Who Should Receive the Smallpox Vaccine?
Routine vaccination for smallpox is not recommended for the general public due to the eradication of the disease. However, certain groups, including
laboratory workers handling orthopoxviruses and military personnel, may receive the vaccine as a precautionary measure.
Are There Risks Associated with the Smallpox Vaccine?
Like all vaccines, the smallpox vaccine carries some risks.
Adverse reactions can include mild side effects such as fever and fatigue, and in rare cases, more serious complications like myocarditis or encephalitis. Vaccination is generally contraindicated in individuals with compromised immune systems.
How is Smallpox Diagnosed in the Event of an Outbreak?
In the event of a suspected smallpox outbreak, rapid diagnosis is crucial. Laboratory confirmation can be achieved through
polymerase chain reaction (PCR) testing, which identifies the variola virus DNA in clinical specimens. Electron microscopy and serological tests may also assist in diagnosis.
What Are the Public Health Measures in Place for Smallpox?
Public health measures for smallpox include surveillance, vaccination, and quarantine protocols. In the event of an outbreak, contact tracing and ring vaccination strategies would be implemented to control the spread of the virus. Ongoing research and stockpiling of vaccines and antivirals are critical components of preparedness plans.Conclusion
Smallpox may be eradicated, but the threat of its use as a bioweapon keeps it a subject of concern in the field of infectious diseases. The approval of tecovirimat and the availability of vaccines like ACAM2000 ensure that we remain prepared for any potential resurgence. Continued vigilance and research are essential to safeguarding public health against this potentially devastating disease.
