Viral Infections Targets
Background
What are Viral Infections?
Viral infections are illnesses caused by viruses, which are much smaller than bacteria and require a host cell to reproduce. There is a vast diversity of viruses, each capable of infecting different types of cells within the body and causing various diseases. These germs consist of genetic material (RNA or DNA) inside a protein coating. Viruses often kill the host organism. Viral infections can be transmitted through various routes, including direct contact, respiratory droplets, contaminated surfaces, food and water, and bodily fluids.
There are several types of viral infections, including respiratory (lung-related), exanthematous (skin), and sexually transmitted infections (STIs). Common symptoms of viral infections include fever, cough, sore throat, runny nose, body aches, fatigue, and sometimes vomiting and diarrhea.
While there are antiviral medications for some viral infections, the primary treatment for many viral infections is supportive care, which includes rest, hydration, and medications to manage symptoms. Prevention strategies include vaccination (for certain viruses), good hygiene practices (such as frequent handwashing), avoiding close contact with infected individuals, and safe food and water consumption.
What Causes Viral Infections?
Researchers have identified over 1,000 viruses that affect humans. They can get into your body through your nose, mouth, eyes, anus or genitals, or through a break in your skin. All of us will get viral infections at some point. But you’re at increased risk of serious illness from certain types of viruses if you:
- Are under 5 or over 65.
- Have certain health conditions, like diabetes, asthma, COPD or other chronic lung disease.
- Have a weakened immune system (from HIV/AIDS, cancer or immunosuppressive medications).
- Are pregnant.
Once you're exposed to a virus, harmful cells can make copies of themselves in your body, which can make you sick and cause symptoms. A virus can also spread to other cells in your body and eventually spread from person to person. There are many ways you can be exposed to a viral infection, including:
- Direct Contact: Through touching or close contact with an infected person.
- Respiratory Droplets: When an infected person coughs or sneezes, releasing droplets that can be inhaled by others.
- Fecal-Oral Route: Ingesting food or water contaminated with fecal matter from an infected individual.
- Bloodborne Pathogens: Through contact with infected blood or other bodily fluids.
- Vector-Borne: Some viruses are transmitted by insects or other animals, such as mosquitoes for dengue or Zika virus.
What are the Types of Viral Infections?
There are many types of viral infections. Some of the most common types include:
There are many different types of viruses and they cause a wide variety of diseases. In some common types of diseases, we have sorted out the corresponding virus types of them for reference.
Symptoms of Viral Infections
Since symptoms of viral infections depend on the part of your body that’s affected, the signs of a viral infection can vary a great deal. Based on the type of virus you have, symptoms can vary from mild to severe.
How to Treat Viral Infections?
Specific medications are only available for a few viral infections. For viruses that can cause life-threatening or chronic illness, a provider may prescribe antiviral medications or treatment that prevents you from getting sick after being exposed to a virus.
At-home remedies is the first line of treatment for a viral infection. For infections that rarely cause serious illness, like the common cold, you can usually treat the symptoms at home while you wait for them to go away on their own. This remedy not only improves your symptoms but reduces the risk of spreading your infection to others. Additionally, some viral infections can cause dehydration, so it's best to stock up on fluids by drinking water, broth, or sports drinks with electrolytes.
Antiviral medications stop viruses from making more copies of themselves (replicating). They can be used to manage chronic infections or shorten the length of some respiratory infections. They can only treat one type of virus — they don’t work on other viruses. Antivirals are available for the flu, COVID-19, hepatitis B and C, HIV and mpox.
Over-the-Counter Medications can help reduce fever, headache, cough, and congestion—based on the exact symptoms you have. Based on your symptoms, your healthcare provider may recommend:
- Antihistamines, such as Zyrtec (cetirizine) or Dimetapp (brompheniramine)
- Decongestants, such as Sudafed (pseudoephedrine) and Afrin (oxymetazoline)
- Non-steroidal anti-inflammatory drugs (NSAIDs), such as Bayer (aspirin), Motrin (ibuprofen) or Naprosyn (naproxen)
- Analgesics (pain-relievers/fever reducers) like Tylenol (acetaminophen)
Case Study
Case Study 1: Active Recombinant Human ACE2 protein (ACE2-185H)
Neutralizing antibodies recognizing the viral spike protein are more revealing. Here, researchers present a cell-free quantitative neutralization assay based on the competitive inhibition of trimeric SARS-CoV-2 spike protein binding to the angiotensin-converting enzyme 2 (ACE2) receptor. This high-throughput method verified with a panel of 206 seropositive donors with varying degrees of infection severity and virus-specific immunoglobulin G titers, achieving 96.7% sensitivity and 100% specificity. Furthermore, it allows for the parallel assessment of neutralizing activities against multiple SARS-CoV-2 spike protein variants of concern. They found that although most sera had high activity against the 2019-nCoV parental spike protein and, to a lesser extent, the α (B.1.1.7) variant, only 58% of serum samples could efficiently neutralize a spike protein derivative containing mutations present in the β (B.1.351) variant.
Fig1. The results of a cross-validation study between S3-ACE2 surrogate neutralization assay and a SARS-CoV-2 CPE neutralization assay are shown. (Craig Fenwick, 2021)
Case Study 2: Active Recombinant COVID-19 Spike protein receptor binding domain (RBD) (Spike-190V)
Since its discovery, COVID-19 has rapidly spread across the globe. Despite numerous advances, there remains an urgent need for accurate and rapid point-of-care diagnostic tests and better therapeutic treatment options. To contribute chemically distinct, non-protein-based affinity reagents, we report here the identification of modified DNA-based aptamers that selectively bind to the S1, S2, or receptor-binding domain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. Several aptamers inhibit the binding of the spike protein to its cell-surface receptor angiotensin-converting enzyme 2 (ACE2) and neutralize authentic SARS-CoV-2 virus in vitro, including all variants of concern. With a high degree of nuclease resistance imparted by the base modifications, these reagents represent a new class of molecules with potential for further development as diagnostics or therapeutics.
Fig2. SOMAmers were screened for binding spike S1 domain. (Amy D Gelinas, 2023)
Case Study 3: Recombinant Human NPC1 protein (NPC1-1339H)
Ebolaviruses cause severe disease in humans, and identification of monoclonal antibodies (mAbs) that are effective against multiple ebolaviruses are important for therapeutics development. Here researchers describe a distinct class of broadly neutralizing human mAbs with protective capacity against three ebolaviruses infectious for humans: Ebola (EBOV), Sudan (SUDV), and Bundibugyo (BDBV) viruses. They isolated mAbs from human survivors of ebolavirus disease and identified a potent mAb, EBOV-520, which bound to an epitope in the glycoprotein (GP) base region. EBOV-520 efficiently neutralized EBOV, BDBV, and SUDV and also showed protective capacity in relevant animal models of these infections. EBOV-520 mediated protection principally by direct virus neutralization and exhibited multifunctional properties.
Fig3. Capacity of mAbs to inhibit NPC1-C binding to GPCL. (Pavlo Gilchuk, 2018)
Related Resources
Viral infections are illnesses you get from tiny organisms that use your cells to make more copies of themselves (viruses). Viral infections commonly cause respiratory and digestive illnesses, but viruses can also infect most other parts of your body.
Viral infections are common and usually not serious. We manage colds, the occasional stomach bug, and bumps and sores on our skin on a regular basis. But some viruses cause life-threatening illnesses, and some common illnesses — like the flu — can turn serious. This is why it’s important to take steps to protect yourself and those around you from viral infection. Vaccinations, good hand-washing habits and safe sex can all help you stay healthy.
