by Pauline Anthonette De Juras | Hachimoji
It has been well over a year since the SARS-CoV-2 virus started wreaking havoc all around the world. At present, this virus continues to infect people and cause the deadly COVID-19. However, as time progresses, the then unknown virus is now becoming more familiar as new information is being discovered by scientists. To bridge these new discoveries to the general public, institutions like the World Health Organization (WHO) take the lead in spreading factual yet simplified versions of the newly discovered information through different media and platforms. Some of the commonly heard terms nowadays are those relating to the variants of SARS-CoV-2—variants of concern and interest. These emerging terminologies also bring about questions on the implications of these variants, especially when it comes to the effectiveness of the vaccines made to combat the spread of the virus.
What are variants?
Variants are defined by the United States’ Centers for Disease Control and Prevention (CDC) as the genetic code of a virus having one or more mutations. Moreover, mutations refer to a single change in a virus’s genetic code. For viruses with RNA as their genetic material, gradual development of mutations is inevitable. Hence, mutations will occur as long as SARS-CoV-2 continues to spread. Most of the time, these mutations only cause minimal effects on the virus’s properties. However, some mutations affect the virus’s properties, such as its transmissibility, severity of the disease it causes, and the efficacy of vaccines against the virus.
How are variants named and classified?
These variants have far more complex names in the scientific field but for the public, these are commonly named following the letters in the Greek alphabet (i.e. Alpha, Beta, Gamma, Delta, etc.). For example, the Delta variant as known by the public is termed as B.1.617.2 in the scientific field. WHO together with experts in nomenclature and virus taxonomy, and national authorities have decided on this naming system to easily label key variants of SARS-CoV-2. This system is established for easier recall and to prevent the use of the place of origin to identify a specific variant which may lead to diescrimination and cause countries to withhold information on emerging variants.
Only variants of interest and variants of concern are being labelled by WHO. Variants of interest (VOI) are those with predicted or known mutations that affect the virus’s properties, those that cause significant community transmission in multiple countries, or those that can turn other epidemiological events into an emerging risk to global public health. At present, WHO has listed the Lambda and Mu variants under this classification. Meanwhile, variants of concern (VOC) are those variants that exhibit increased transmissibility, increased severity of COVID-19, and decreased effectiveness of implemented safety protocols and available diagnostics, vaccines, and therapeutics. There are currently four variants listed under this category — the Alpha, Beta, Gamma and Delta variants.
VOCs and VOIs can be reclassified depending on its current effect. An example of which is the Delta variant which was first classified as a VOI in April 2021 but was later reclassified as a VOC in May 2021.
SARS-CoV-2 variants in the Philippines
All four VOCs have hit the Philippine headlines and some continue to persist in the country. These variants are noted to cause more severe illness and death. One of which is the Alpha variant which was declared as a VOC in December of 2020. This variant has mutations in its spike glycoprotein causing this particular variant to have a significantly higher binding affinity towards the ACE2 receptor in humans. A study by Dutta in 2021 also shows that this variant causes those infected to have a higher viral load and exhibit a moderate increase in the risk of requiring supplemental oxygen.
Another is the Delta variant, which was declared as a VOC in May 2021. This variant is the primary cause of the most recent surge of cases in the country. This variant is mostly known for its transmissibility and is dubbed by Johns Hopkins Medicine as the most contagious form of the SARS-CoV-2 virus so far. As of November 8, 2021, the health department reported that the total number of Delta variant cases in the country has reached 5,982, making it the most dominant variant in the country so far.
Recently, a new variant was detected in the country. On November 8, 2021, the Philippines reported its first case of the Kappa variant. The patient’s sample was taken back on June 2, 2021 and has long been marked as recovered. The kappa variant came from the same lineage as the Delta variant. It used to be under the classification of VOI in April 2021 but has been demoted as a variant under monitoring in September 2021 by the World Health Organization. Its transmissibility, severeness, and other effects are yet to be reported.
Effects of vaccines on these variants
Vaccines continue to serve as an added protection against many diseases, including COVID-19. The vaccines for COVID-19 lessens the risk of contracting SARS-CoV-2, which is the virus responsible for the said disease. All vaccines approved by the World Health Organization for emergency use are thoroughly evaluated to ensure its safety, quality, and efficacy.
Efficacy is a commonly used term that refers to the vaccine’s ability to reduce the risk of getting sick in an ideal environment. This is measured in a controlled clinical trial wherein the number of vaccinated people who contracted COVID-19 is compared with the number of people vaccinated with a placebo (dummy vaccine) who contracted COVID-19. Hence, if the vaccine is said to have a 75% efficacy, it implies that in a vaccinated population, 75% will not contract the disease when they come in contact with the virus. Efficacy is different from effectiveness, such that the latter refers to how well the vaccines work in real life. Various factors come into play to measure the effectiveness of vaccines, thus vaccine efficacy is used to describe the vaccines.
In the currently available COVID-19 vaccines, some require two doses, while others only require a single dose. In 2-dose COVID-19 vaccines, the 1st dose provides partial protection and the 2nd dose boosts the previous protection. Then, in single dose COVID-19 vaccines, the desired immunity is already achieved in the 1st dose. In both types of vaccines, maximum immunity is only achieved 2-3 weeks after the last dose. Although vaccines give added protection, full immunity against the deadly virus is not guaranteed. However, it is highly effective in preventing severe illness and hospitalization. Additionally, WHO asserts that the chance of vaccinated people getting severly sick or even dying is very rare.
Against emerging variants, Johns Hopkins Medicine noted that some immune responses could be less effective against some variants. Nevertheless, the currently available vaccines are proving to be still effective against the current variants and remain reliable in preventing severe illness and death. The vaccines’ broad immune response averts the possibility of rendering the vaccines completely ineffective against the variants.
As more information on the SARS-CoV-2 virus and the COVID-19 becomes available to the public, it is important to make sense of this information. Being able to understand various information regarding the virus and disease allows people to make more informed decisions.
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