COVID-19, caused by the novel coronavirus SARS-CoV-2, is an infectious disease that first appeared in late 2019 and swiftly spread across the globe, leading to one of the most significant public health crises in modern history. The virus primarily targets the respiratory system and can cause symptoms ranging from mild cold-like signs to severe pneumonia and life-threatening complications. Its high transmissibility and the emergence of multiple variants have made controlling the pandemic challenging, prompting widespread changes in daily life, healthcare systems, and global economies.
Since its outbreak, COVID-19 has highlighted the critical importance of timely medical intervention, vaccination, and public health measures such as social distancing and mask usage. Scientists and healthcare professionals continue to work tirelessly to understand the virus better, develop effective treatments, and improve prevention strategies. Despite the progress made, COVID-19 remains a dynamic threat, underscoring the need for continued vigilance, accurate information, and collective action to minimise its impact and protect communities worldwide.
What is COVID-19?
COVID-19 is a highly contagious respiratory illness caused by the novel coronavirus SARS-CoV-2(Severe Acute Respiratory Syndrome Coronavirus 2). The name Covid-19 stands for Coronavirus Disease 2019, the year it was first identified. It was first discovered in Wuhan, China, in December 2019 and quickly spread across the globe, leading to a pandemic declared by the World Health Organization (WHO) in March 2020.
COVID-19 spreads through respiratory droplets when an infected person coughs, sneezes, speaks, or breathes. This disease can range from mild to severe, and in some cases, it can be fatal, espicially for older adults and those with underlying health conditions like heart disease, diabetes, or weakened immune systems. Common symptoms include fever, cough, fatigue, shortness of breath, and loss of taste or smell. Though many people recovered without any special treatment, others, like older people or people who are suffering from any chronic disease, develop serious complications like pneumonia or acute respiratory distress syndrome(ARDS).
Governments and health organisations worldwide have implemented various public health measures, including lockdowns, vaccination programs, mask mandates, and social distancing, to slow down the spread of COVID-19. Despite significant progress in managing the disease, ongoing mutations of the virus mean that COVID-19 remains a global health concern, requiring continued awareness, prevention, and vaccination efforts.
Symptoms of COVID-19
COVID-19, caused by the SARS-CoV-2 virus, affects people in different ways. Some people experience only mild symptoms or none at all and get well after taking some measures without the need to go to the hospital. While some people may face severe or life-threatening complications, particularly those individuals who have an underlying health condition or have a weak immune system.
Usually, COVID-19 takes 2 to 14 days to show up if you come in contact with the virus. So initially, you can feel like just a simple cough or cold, but in a short period, it can turn into serious complications. Symptoms can include:
- Dry cough
- Shortness of breath
- Loss of taste or smell
- Extreme tiredness
- Digestive symptoms like upset stomach, vomiting, or diarrhea.
- Headaches, body or muscle aches.
- Fever or chills
- Cold-like symptoms like congestion, a runny nose, or a sore throat.
Some people with COVID-19 may have only mild symptoms, or none at all. Those who test positive but don’t feel sick are called asymptomatic, and this is common in children. Others might not feel symptoms right away but develop them later; these are known as presymptomatic individuals. Importantly, both groups can still spread the virus, even if they appear healthy.
In many cases, symptoms start off mild but can worsen within 7 to 14 days, especially in people with underlying health conditions. While most individuals recover with mild to moderate illness, COVID-19 can lead to serious complications, including hospitalisation or death, particularly among older adults and those with chronic diseases like diabetes, heart problems, or weakened immune systems.
COVID-19 symptoms initially start from mild symptoms but can turn into life-threatening symptoms, depending on factors like age, overall health, and immune response. You can identify your severity stage depending on the symptoms:
- Mild: cold or flu-like symptoms with no impact on breathing.
- Moderate: signs of infection in the lungs, but the oxygen level remains normal.
- Severe: lungs struggle to supply oxygen, often requiring hospitalisation and oxygen support.
- Critical: complete respiratory failure, multi-organ damage, and need for intensive care.
People who have any pre-existing health issues like diabetes, heart disease, obesity, and a weak immune system, and older people are at higher risk, as they have low immunity and their bodies are unable to fight the virus effectively.
In rare cases, COVID-19 can cause a serious condition called Multisystem Inflammatory Syndrome. In this case, there is an inflammation in different parts of the body, like the heart, lungs, brain, and kidneys. This condition in children is named MIS-C, and in adults, MIS-A.
When To See A Doctor?
If you test positive for COVID-19 or have symptoms, then immediately contact your health care professional. They can guide you about testing, whether you require further treatment, or if your condition can be managed at home.
People who are at high risk of serious illness may be given medication to help stop the COVID-19 virus from spreading in the body. Doctors may recommend regular health check-ups to monitor your health.
If you or someone else has the following symptoms, then immediately seek medical help:
- Trouble breathing or shortness of breath.
- Lips, face, or nails turning pale, gray, or blue.
- Sudden confusion or trouble staying awake.
- Ongoing chest pain or pressure.
These are symptoms that signify that your illness is getting serious, and if you yourself start feeling something is wrong with your health, or are unsure about whether your symptoms are getting serious, immediately let your healthcare provider know about your health.
Causes Of COVID-19 and How It Spreads?
COVID-19 is caused by a virus, SARS-CoV-2, commonly known as severe acute respiratory syndrome coronavirus 2. It mainly spreads from person to person, even from the individual who is infected but has no symptoms.
When a person infected from covid virus coughs, sneezes, talks, sings, or even breathes, tiny particles or droplets carrying the virus are released into the air. These droplets can:
- Land on someone else’s face, especially if they are close by.
- Be breathed in by others, especially in crowded or poorly ventilated spaces.
- Fall onto surfaces, if someone falls onto a surface and then touches their eyes, nose, or mouth, they could become infected.
Can You Get COVID-19 More Than Once?
Yes, you can get COVID-19 more than once, even if you’ve already had it or been vaccinated. Here’s why:
- Immunity can fade over time, just like many viruses; your body’s protection against COVID-19 may get weaker months after infection or vaccination.
- High exposure increases risk; if you are in crowded places or around many infected people, the amount of virus you breathe in can affect your immune system.
- The virus keeps changing, COVID-19 is caused by a virus that mutates. These changes, called variants, can make it harder for your body to recognise and fight the virus, even if you have been infected or vaccinated before.
- As the virus spreads, it creates new versions of itself. Some of the variants may be different enough that past immunity doesn’t fully protect you.
Can Animals Get COVID-19?
The virus COVID-19 can affect certain animals like cats, dogs, ferrets, and hamsters, especially if they are in close contact with someone infected. Just like humans, these pets can also exhibit symptoms like coughing, sneezing, or tiredness, but can recover with proper care.
Though it is very rare to get a virus from animals. Mainly, transmissions happen from person to person. If you are infected with the COVID-19 virus, it would be best to avoid your pet as you would with other people to reduce the spread of the virus further.
Risk Factors
While COVID-19 can affect anyone, a certain group of people is more likely to get seriously ill if they are infected with the virus. These people include:
1. Older adults, espicially those over 65
2. Babies under 6 months old
3. People who have any chronic illness, like:
- diabetes(type1 or type 2)
- heart disease or high blood pressure.
- lung conditions like asthma or COPD)
- obesity or overweight
- cancer( history of cancer)
- kidney or liver disease
4. Weakened immune system
5. Sickle cell disease or thalassemia
6. Pregnant women
7. People with neurological conditions, such as stroke, dementia, or alzheimer’s
8. Smokers or people with long-term exposure to smoke
9. Unvaccinated individuals
If you are living in group settings, like nursing homes or care facilities, then it can also raise the risk if there is anyone infected in the group.
Other factors that increase the risk of getting infected
- Someone you live with has a virus.
- You spend time in crowded, poorly ventilated places.
- You are in close contact with someone who has COVID-19 for more than 30 minutes.
- You don’t wear a mask when needed, especially around sick people or in high-risk areas.
Can I Catch COVID-19 From Surfaces?
It is very rare to catch COVID-19 from touching surfaces, but it is possible. The virus may land on things like doorknobs, tables, or bathroom handles when an infected person coughs, sneezes, or touches them. If you immediately touch the surface and put your hands on your face, especially your mouth, nose, or eyes, there is are chance that you might get infected. So it is better to wash your hands frequently and clean the surfaces you use a lot.
Post-COVID-19 syndrome
After recovering from COVID-19, some people continue to feel unwell for weeks or even months. This ongoing condition is known as Post-COVID-19 Syndrome, or more commonly, Long COVID. It’s also called post-COVID conditions, long-haul COVID, or PASC (Post-Acute Sequelae of SARS-CoV-2). Long COVID can develop even after mild or symptom-free cases and affects people of all ages.
Common symptoms include extreme tiredness (fatigue), brain fog, trouble breathing, chest pain, sleep problems, joint or muscle pain, and mood changes like anxiety or depression. Some may also experience memory issues, difficulty concentrating, or a lingering loss of taste and smell.
While the exact cause is still being researched, it may be related to immune system changes, inflammation, or damage to organs caused by the virus. Getting vaccinated may reduce the risk of developing Long COVID. If you continue to feel unwell after a COVID-19 infection, talk to a healthcare provider. Early care and proper support can help you manage symptoms and improve recovery.
Prevention
The Centers for Disease Control and Prevention (CDC) recommends that every individual aged 6 months and older get the COVID-19 vaccine. Vaccination enhances your system and lowers the risk of serious illness or death from COVID-19.
During the 2024–2025 season, these three COVID-19 vaccines are commonly administered to protect against circulating strains, including the latest Omicron subvariant, JN.1.8.1.
1. Pfizer-BioNTech( for above 6 months and older)
- Children aged 6 months to 4 years are considered up to date after receiving three doses of the 2024-2025 Pfizer-BioNTech COVID-19 vaccine. If a child has already received one dose of an earlier Pfizer-BioNTech COVID vaccine, two additional doses of the 2024-2025 formula will complete their series. For children who have had two previous doses, just one dose of the 2024-2025 vaccine is needed to be up to date.
- People aged 5 and older are considered up to date after receiving one dose of the 2024–2025 Pfizer COVID-19 vaccine.
2. Moderna (for ages 6 months and older)
- Children 6 months to 4 years are up to date after two doses. If they had earlier Moderna vaccines, one dose would be enough.
- People above 5 and older are up to date with one 2024-2025 Moderna dose.
3. Novavax( for 12 and older)
- People and older adults are up to date after one 2024-2025 Novavax dose for the COVID-19 vaccine.
Most people aged 5 and older with a normal immune system can get any vaccine authorised for their age and don’t need to stick to the same vaccine every time. However, some groups should stay with the same vaccine maker for all doses. This includes young children (6 months to 4 years), people 5 and older with weakened immune systems, and those starting or finishing the two-dose Novavax series.
For People with Weakened Immune Systems
If your immune system is moderately or seriously weakened, your healthcare provider may recommend extra doses of the COVID-19 vaccine to help protect you better. The FDA has also approved a special antibody treatment called pemivibart (Pemgarda) to help prevent COVID-19 in some people with weakened immunity.
Other Ways to Stop COVID-19 Spread
Besides vaccination, you can reduce your risk by:
- Get Vaccinated
Vaccination is one of the best ways to prevent severe illness and death. Approved vaccines like Pfizer, Moderna, AstraZeneca, and Johnson & Johnson are safe and effective. Booster shots are also recommended for ongoing protection. - Wear a Mask
Wearing a well-fitting mask in indoor or crowded places helps stop the spread of the virus through respiratory droplets. Make sure it covers both your nose and mouth. - Practice Social Distancing
Stay at least 6 feet away from others, especially in public spaces or gatherings. This reduces the chance of getting infected. - Wash Hands Often
Clean your hands regularly with soap and water for 20 seconds. If unavailable, use hand sanitiser with at least 60% alcohol. - Avoid Crowded and Poorly Ventilated Areas
Stay away from places with large groups and limited airflow. Good ventilation lowers the risk of airborne spread. - Test and Isolate When Needed
Get tested if you have symptoms or have been in contact with someone who tested positive. Isolate if you’re infected, and follow quarantine guidelines if exposed. - Keep Surfaces Clean
Disinfect high-touch surfaces daily, like doorknobs, switches, phones, and keyboards, to kill any lingering virus.
Frequently Asked Questions?
1. What is SARS-CoV-2?
SARS-CoV-2 is the virus that is responsible for causing COVID-19. It spreads through the air via droplets and can lead to symptoms like fever, cough, and difficulty in breathing.
2. What are the stages of COVID-19?
- Exposure– when you come into contact with a virus.
- Incubation– there are no visible symptoms, but the virus is in the body.
- Early symptoms- You start feeling mild symptoms like a cough, fever, sore throat, and tiredness.
- Worsening Symptoms– you start feeling difficulty in breathing, chest pain, or a high fever.
- Severe illness– You may need to be hospitalized or receive oxygen support.
- Recovery– Most people recover, but some may have lasting symptoms called Long COVID.
3. Am I still contagious after a negative COVID-19 test?
If you test negative for COVID-19, it often means that you are not contagious, but it’s not guaranteed. Especially if you tested too early or still have symptoms, there’s a good chance you could still have COVID-19 and be contagious.
4. What are the current symptoms of a new strain of COVID?
The current COVID-19 strains (like NB.1.8.1 and LF.7) mainly cause mild symptoms such as:
- Sore throat
- Low-grade fever
- Fatigue
- Cough
- Runny nose
- Headache
- Body aches
5. How long should I isolate myself after testing positive for COVID-19?
If you tested positive for COVID-19, then:
- Isolate yourself for at least 5 days after testing positive for coronavirus.
- Just have full rest for 4-5 days. If you still have a fever, keep isolating yourself.
- After 5 days, if you are feeling better and dont have any symptoms for 24 hours, then you can end isolation.
Wear a mask during the period and take proper measures. If symptoms persist, then seek immediate medical help.
