A chronology of SARS-CoV-2, the virus that causes coronavirus illness 2019 (COVID-19) and is the cause of the COVID-19 pandemic, is included in the timeline of the COVID-19 pandemic.

On or around November 16, 2019, Wuhan, People’s Republic of China, reported the first human cases of COVID-19. The United States saw its first human case on January 21, 2020. On January 30, 2020, and March 11, 2020, respectively, the World Health Organization designated the COVID-19 outbreak as a Public Health Emergency of International Concern and a pandemic. It is unclear exactly how mainland Chinese people contracted the SARS-CoV-2 virus in the past or in the beginning as of this writing (October 2022).  Additionally, certain advances might be fully or widely understood



Individuals infected with COVID-19 have reported a broad spectrum of symptoms, from minor ailments to serious infections. Within two to fourteen days of viral exposure, symptoms may manifest. Anybody may experience minor to severe symptoms. Symptoms that could exist include:

  • Fever or chills
  • Cough
  • Shortness of breath or difficulty breathing
  • Fatigue
  • Muscle or body aches
  • Headache
All potential symptoms are not included in this list. The symptoms can vary based  immunization status and could change with new COVID-19 variations. COVID-19 can cause severe illness in older adults and those with underlying medical disorders such as diabetes, heart disease, or lung disease.
  • New loss of taste or smell
  • Sore throat
  • Congestion or runny nose
  • Nausea or vomiting
  • Diarrhea


  • Trouble breathing
  • Persistent pain or pressure in the chest
  • New confusion
  • Inability to wake or stay awake
  • Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone


COVID-19 and influenza (Flu) are respiratory infections that spread easily, although they are caused by distinct viruses. Similar to how influenza viruses cause the flu, SARS-CoV-2 is the coronavirus that causes COVID-19. Since some of the symptoms of COVID-19 and the flu are similar, you cannot distinguish between the two diseases by their symptoms alone. Certain PCR tests have simultaneous flu and COVID-19 differentiation capabilities. In many testing locations, COVID-19 and flu tests are offered independently in case one of these tests is not available. If you have symptoms, see a doctor about getting tested for COVID-19 and the flu.

source: National Center for Immunization and Respiratory Diseases (NCIRD), Division of Viral Diseases

COVID-19 AND INFLUENZA what the difference


The virus known as coronavirus disease 2019 (COVID-19) is extremely contagious. COVID-19 has the same potential for change over time as other viruses. A number of causes, including environmental ones, may cause these alterations. Certain modifications are small and have little effect on the virus’s general characteristics, but other modifications, like making the virus more contagious, can have a big influence.

Mutations refer to modifications made to the virus. A virus is classified as a variation if it acquires one or more of these alterations.

It should be mentioned that these shifts are anticipated by the scientific community and are continuously tracked to support critical medical decisions. This has assisted the medical industry in developing vaccines, including those produced by Pfizer, Sinovac, and AstraZeneca.

Alpha, Beta, Delta, and, more recently, Omicron are the known variations found in Malaysia. On a more positive note, the Director-General of Health stated that the second COVID-19 test of a South African student, the country’s first reported instance of Omicron, was negative. However, the Ministry of Health has issued a warning about the risk of additional instances.

The coronavirus spreads by infecting cells in your body and then replicating itself. There may be times when the virus’s genetic material is erroneously transferred during the copying process, resulting in a mutation. This occurs entirely by chance and at random. Not all varieties will survive, but some will and will spread throughout the body and, eventually, to other people.

COVID-19 variants should not be referred to as ‘viral strains’ because they are simply a new version of the virus that has undergone a genetic alteration that differs from the original COVID-19 sequence. A strain is more similar to a virus, with quite different features.

VARIANT What cause the variant

  • WHO label : Omicron
  • Pango lineage code : B.1.1.529
  • First documented : 24th November, 2021 (first sample collected 9th November)
  • Country/Region : South Africa (November 2021)
  • VOC designation : 26th November, 2021
  • No. of mutations : 32 mutations on the spike protein (preliminary data)
  • Infectivity : High (preliminary data)
  • Symptoms : Mild headaches for several days (preliminary indications of similar symptoms as other variants)
  • Risk of reinfection : High (preliminary data)
  • Notes :
    In October 2022, the World Health Organization (WHO) reported a new
    subvariant of the Omicron variant, XBB, that has been identified in 26
    countries, including Malaysia. XBB is a combination of two other BA.2 Omicron subvariant, which are BA.2.10.1 and BA.2.75.
In December 2022, it was suspected that two novel Covid-19 variations – a sublineage of Omicron – designated BA.5.2 AND BF.7 were driving the increase in infections in China. Malaysia had 4,148 cases of BA.5.2 infection and three cases of BF.7 infection as of December 31st, 2022. When compared to the other versions, both of the new variants had a higher transmission rate.
  • WHO label : Delta
  • Pango lineage code : B.1.617.2
  • First documented : December 2020
  • Country/Region : India (October 2020)
  • VOC designation : 11th May, 2021
  • No. of mutations : High
  • Infectivity : Twice as contagious than other earlier variants
  • Symptoms : Mild headaches, fever, persistent cough, sore throat (Shares symptoms as the original virus)
  • Risk of reinfection : High (especially among unvaccinated)
  • Notes : Delta accounts for at least 90 percent of new cases, and is a significant risk to unvaccinated groups. There is also some confusion between the Delta variant and another variant that is labelled ‘Delta Plus’. This is misleading, as ‘Delta Plus’ is an offshoot of the Delta variant, which is called AY.4.2. AY.4.2 is not a standalone variant, but instead part of the Delta family of variants. To put it simply, it is the Delta variant with a few specific mutations.


  • WHO label: Alpha
  • Pango lineage code: B.1.1.7
  • First documented: September 2020
  • Country/Region: United Kingdom
  • VOC designation: 18th December 2020
  • No. of mutations: Approximately 23, maybe more
  • Infectivity : 1.5 times more transmissible than earlier variants
  • Symptoms : Fever, shortness of breath, cough, fatigue, change of sense of taste/smell (shares symptoms as the original virus)
  • Risk of reinfection : High (especially among unvaccinated)
  • Notes : Found in 192 locations worldwide, persons infected with the Alpha variant are 1.6 times at greater risk of death. Some mutations may also be found in the beta and gamma variants.


  • WHO label : Beta
  • Pango lineage code : B.1.351
  • First documented : May 2020
  • Country/Region : South Africa
  • VOC designation : 18th December, 2020
  • No. of mutations : High
  • Infectivity : 50 percent more transmissible than earlier variants
  • Symptoms : Mild headaches, fever, persistent cough, sore throat (Shares symptoms as the original virus)
  • Risk of reinfection : High (especially among unvaccinated)
  • Notes : Shares three mutations first seen in the Alpha variant, and is known to be more resistant to antibodies created through vaccination or recovery from a previous infection. Despite its infectivity, there is little evidence that Beta causes significant harm to an infected person’s health. Beta has also been overtaken by the more aggressive Delta variant, though Beta remains listed as a VOC by the WHO.


  • WHO label : Gamma
  • Pango lineage code : P.1
  • First documented : November 2020
  • Country/Region : Brazil
  • VOC designation : 11th January, 2021
  • No. of mutations : High
  • Infectivity : Estimated 1.7 to 2.4 times more transmissible than other variants
  • Symptoms : Mild headaches, fever, persistent cough, sore throat (Shares symptoms as the original virus)
  • Risk of reinfection : High (especially among unvaccinated)
  • Notes : Most vaccines now offer significant protection from the Gamma variant.


source from :

Skip to content