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Viruses tend to evolve over time. The SARS-COV-2 virus has already undergone thousands of mutations, and nearly every infection in Hong Kong has its own genetic fingerprint. We can use this method to link infections together, and follow how closely the ‘fingerprints’ match.

Researchers in the UK identified a new variant in late 2020, now known as the Alpha variant. Various variants were also identified in South Africa (the Beta variant), Brazil (the Gamma variant), and India (the Delta variant). While the mutations differ in their exact positions, they share a number of characteristics, including evidence of higher transmission rates. In other words, these variants are more infectious. As a result of them, we have seen an increase in infections in various waves during the last year. In autumn of 2021, an outbreak of Delta infections caused an increase in cases in Europe and the USA. Omicron currently makes up the majority of new infections worldwide.

The new variants have already spread worldwide, and have accelerated the epidemic in the areas where they spread. They’re like iPhones. The iPhone 4 seemed like it was good at its job, but as it evolved, the iPhone 5 was better and quickly became more popular. Often the evolution is gradual, like the 5S, but sometimes there’s a leap, like a larger screen or better camera, and that particular model becomes dominant in a very short period of time. It’s the one everyone wants, so it tends to take over. Other companies try to copy it. This is how viruses work. We don’t usually see any benefits from random mutations, but sometimes there’s a big jump and the virus gets stronger, faster, and better at spreading. Alpha, which nearly swept the US, UK, and Europe in late 2020, wasn’t as infectious as the Delta. In 2021, Delta spread to almost every country on Earth. Omicron appears better equipped and more capable of spreading than Delta. Over the next few months, it will be the ‘most popular model’ in the world.

It is incredibly common for viruses to develop mutations, and the majority of them are not beneficial. We can, however, identify specific areas in the viral code that are more likely to produce a variant with an advantage. Metaphorically, maybe it’s the code for a bigger screen or better camera. However, most of these mutations fail. These ‘variants of concern’ can be tracked by scientists to see if they gain traction and become more widespread. This is what has been noted with the Omicron variant which has a large number of mutations especially in the areas known to confer an advantage. It was immediately identified as ‘one to watch closely’. Having initially been found in South Africa, it is now the most common variant in most countries worldwide.

The number of local epidemics is on the rise. There is evidence of immune escape and reinfection in South Africa, the UK, and Denmark as well. In other words, the rapid growth may be caused by a combination of increased transmissibility and greater resistance to existing immunity. All of these locations have excellent testing capacity and high prior immunity from a combination of natural infections and vaccination. Data from the UK and Denmark show that epidemics double every two days. This suggests that a large wave of infections is on its way. This wave is already trending larger than the Delta wave. The early data indicate that vaccinations are less effective at preventing transmission and mild disease against Omicron than against other variants. Still, vaccinations continue to offer good protection against death and severe disease. Booster doses significantly enhance this protection. More solid vaccination data will be available in the coming weeks.

Going forward, the key question is how severe the disease is. There have been a number of reports from South Africa, the UK and Denmark suggesting that the disease associated with Omicron is milder. There are some reasons for cautious optimism, but it is important to remember that South Africa has a very young population with high levels of natural immunity. Vaccinations and natural immunity are also highly prevalent in the UK and Denmark. The impact of any variant will therefore vary from one location to another. We cannot assume that mild disease in highly immune populations will behave the same way in infection-naive populations such as Hong Kong and China. It is also important to recognize that even a small wave of disease can pose a significant threat to a health system. A small percentage of a very large number may still be a significant number over a short period of time. South Africa’s health system was also under considerable strain due to the number of healthcare workers who needed to be isolated with mild infections.

Ultimately, understanding the threat posed by new variants boils down to three key questions.

  1. Is the new variant more infectious?
  2. To what degree can the variant escape existing immunity (vaccine induced or natural)?
  3. Does the new variant produce more mild or more severe disease?


Data over the next few weeks will provide answers to the question about disease severity.

We have previously explained the important difference between the severity of disease and the severity of an epidemic. COVID-19 has the potential to overwhelm health systems because of its rapid growth. The graph below demonstrates this issue. It compares a disease which is 50% more severe, continuing with slightly higher fatality rates, versus a disease which is 50% more infectious, producing a significant increase in mortality due to the rapid increase in the number of infected cases.

It is important not to lose sight of how well the epidemic has been managed in Hong Kong. COVID-19 is a mild disease in the majority of cases, but has the potential to overwhelm health systems because of a potentially rapid increase in the numbers of infected patients. Avoiding excessive strain on the hospital system is one of the main goals of the public health controls. The new variants increase the risk of an epidemic taking hold and spreading quickly. We’ve seen recently in New Zealand and Australia how brittle a Zero Covid strategy can be.

There are only two ways in which an individual or population can develop immunity, either by contracting the disease or through vaccination. The potential impact of these more infectious variants spreading through our densely populated city makes widespread infection a serious health threat. If an epidemic took hold in Hong Kong we would expect to see high mortality rates and significant stress to the health system. Vaccination remains the best way of developing population immunity and protecting both our population and health system. This is the reason that public health doctors are advocating so hard for population vaccination even though the current vaccination rates in Hong Kong are so low.

SARS-COV-2 has already proven to be more infectious due to some mutations. In most circumstances, COVID-19 is not a serious disease, but rather it is the nature of the epidemic and its tendency to overwhelm health systems that causes harm. The real challenge now is to overcome vaccine hesitancy and boost vaccination rates, especially among the older and most vulnerable members of the population.

An IVD is a reagent, calibrator, control material, kit, instrument, piece of equipment, apparatus, software, or system that is intended to be used in a test tube or culture dish (in vitro) to examine specimens, including blood and tissues taken from the human body. It can be used alone or in combination.exceptional benefits: decreased total cost of ownership, improved drug-container compatibility, and increased patient safety. Medriva’s PFS provides pharmaceutical manufacturers, health-care providers, and patients with several benefits that include: patient compliance, reduction of dosing errors, minimized risk of contamination, and the promotion of safe injections.

According to Harvard’s Medical Dictionary of Health Terms, an antigen is any substance that the body recognizes as harmful or foreign, which induces the immune system to produce antibodies against it.


A rapid antigen test detects protein fragments on the surface of the coronavirus to determine if those taking the Medriva COVID-19 test are infected with the pathogen. Samples are taken from subjects by swabbing inside the nose or mouth.


Rapid antigen tests are typically administered by using a sterile cotton swab and taking samples from the nasal cavity and adding a liquid solution to get a result.

Here is a short breakdown of the procedure:

  • Swab and rotate the cotton swab inside both nostrils to collect the sample
  • Place the swab in the testing well
  • Add the liquid testing solution
  • Wait for 15 minutes to get the result
  • Read the full step-by-step guide on how to administer the rapid antigen test.

Compared to polymerase chain reaction (PCR) tests, rapid antigen tests are slightly less accurate.

Test accuracy is generally measured by sensitivity and specificity.

  • Sensitivity is defined as the ability to correctly identify subjects with COVID-19.
  • Specificity is defined as the ability to correctly identify subjects without COVID-19.
  • PCR tests have been shown to be up to 100% accurate, although accuracy varies depending on which test is used.

Rapid antigen tests, in comparison, show false-negative rates of up to 20%. Medriva’s rapid antigen test kit accurately identifies 97.6% of people who do have COVID-19, and correctly identifies 99.67% of people without COVID-19.

False negatives occur when a subject is mistakenly diagnosed as not ill. For instance, if someone has COVID-19 and takes a test, if the test results return a negative result, despite the person being infected with the virus, then this is considered a false negative. The test did not correctly identify someone with the coronavirus.

Rapid antigen tests are used to identify people that currently have the virus. Past infections can be identified using other types of tests.

Other than for identifying COVID-19, antigen tests are commonly used to identify:

  • Streptococcus infections
  • Influenza virus
  • Malaria

Depending on where you live, rapid antigen test kits can be found in physical stores and buildings like pharmacies, local healthcare services, and facilities. Depending on where you live, you can also order from the Medriva website by clicking on the buy now button on the menu bar. 

Regardless of whether you have symptoms or not, when you are ready to use this reagent, please do isolation and protection. Wear a face mask or cover your mouth and nose with a tissue when you are coughing and keep distance with other people.

You can always test yourself whether you have symptoms or not. Please note that the test result is a snapshot that is valid for this point in time. Tests should therefore be repeated according to the regulations of the responsible authorities.

Always follow the instructions of use exactly. Perform the test immediately after collecting the sample. Dispense the drops from the test tube only into the designated well of the test cassette. Dispense two drops from the sample tube. Too many or too few drops can lead to an incorrect or invalid test result.


The reason for a clearly visible discoloration of the test strip is that too large a quantity of drops has been dispensed from the sample tube into the test cassette well. The indicator strip can only hold a limited amount of liquid. If the control line does not appear or the test strip is very discolored, please repeat the test with a new test kit according to the instructions for use.

In this case, the test result is to be considered invalid. Please repeat the test with a new test kit according to the instructions for use.

If you cannot clearly determine the result of the test, contact the nearest medical facility applying the regulations of your local authority.

If a horizontal-colored line is visible in the control area (C) as well as in the test area (T),your result is positive, and you should immediately contact the medical facility in accordance with the requirements of your local authorities. Your test result may be checked, and the next steps will be explained to you.

If only a horizontal-colored line is visible in the control area (C), this may mean that you are negative or that the viral load is too low to be recognized by the test. If you experience symptoms such as headaches, migraines, fever, loss of sense of smell and taste, contact the nearest medical facility applying the regulations of your local authority. In addition, you can repeat the test with a new test kit.

This test cassette is for one-time use and cannot be reused or used by multiple people.

Swabbing both nostrils gives you the best chance of collecting sufficient samples to generate an accurate result. It has been observed in some cases that only one nostril has detectable virus, so it is important to collect from both nostrils. Correct swabbing is important to obtain a correct result.

Medriva is built on protection

We strive to achieve patient health. And we’ll get there using innovation, product development, and the most advanced R&D team.
We strive to achieve patient health. And we’ll get
there using innovation, product development, and
the most advanced R&D team.