There are four dominant variants of SARS-CoV-2 spreading among the global population. The four variants are the Alpha Variant (formerly called the UK Variant, first found in London and Kent), the Beta Variant (formerly called the South Africa Variant), the Gamma Variant (formerly called the Brazil Variant), and the Delta Variant (formally called the Indian Variant), as of July 2021.
The emerging COVID-19 variants are classified as either a Variant of Concern (VOCs) or a Variants of Interest (VOIs). The Alpha, Beta, Gamma and Delta variants fall under VOCs, whereas the Eta, Iota, Kappa and Lambda fall under VOIs.
A COVID-19 variant is considered VOCs when the variant brings in major changes in transmissibility and causes severity. VOIs fall on the watch list as no major changes in the pattern of the disease transmissibility has been observed so far.
The Alpha Variant (UK Variant) has a 50 percent increased transmission rate, meaning that it can more easily pass from an infected person to another individual. There is also data to suggest that the severity of disease is greater with this variant strain. Vaccines are still effective.
The Beta Variant, also known as South African Variant, has 50 percent more transmissibility. The Gamma Variant (Brazilian Variant) is more transmissible but more research is needed, and the vaccine efficacy is unknown. As for the Beta Variant, the vaccine is less effective.
The Delta Variant has been shown to have an increased transmission rate. Outcome, treatment, and vaccine response data is in the early stages of study.
The Lambda Variant has only 20 percent transmissibility, and that is why WHO has not labeled it as VOCs. It was first sequenced in Peru in December 2020. According to the GISAID website, there are 705 documented cases of the Lambda Variant in the United States.
Assistant Professor of Epidemiology, Dr Sithar Dorjee, said Bhutan has confirmed the original Wuhan strain and Delta Variant as of now. There are no other strains detected in the country so far.
As for India’s case, all new variants have been detected. In Punjab, it is estimated 80 percent are the UK Variant.
Dr Sithar said Delta Variant is 75 percent more transmissible than the UK Variant. The Delta Variant is known to cause hospitalization in younger age groups 20-40 years old. It also causes pneumonia in a shorter time (quicker hospitalization and lung damages), and relatively more deaths, but it may be related to shortage of oxygen and ICU beds. All vaccines including Covishield can save patients from severe disease (ICU and mortality). However, all vaccines are less effective against the Delta Variant.
New symptoms by the new variants are conjunctivitis, diarrhoea, discoloration of fingers or toes, aches and pains, sore throat and skin rashes, and headache.
Dr Sithar explained that Bhutan, being well covered by vaccines, has less risk of detecting other major variants.
Once the country achieves 80 percent of the vaccine coverage, which includes fully vaccinated children and the eligible population, and also depending upon the risk assessment, the quarantine duration may also be reduced accordingly.
Reports from India suggest that many doctors who have received both vaccine doses, and in the past 2 weeks after booster dose, are testing positive and suffering from mild to moderate disease.
There are high chances of having new variants, if transmissibility remains very high and chances of co-currents of new variants is high, but if the epidemic can be maintained at low threshold level then the probability of a new variant coming in is reduced.
The possibility is still there. So now the Royal Center for Disease Control (RCDC) is planning to start gene sequencing to detect new variants. Dr Sithar said once the Gene Sequencer is installed, RCDC will be collecting a test positive sample of the returnees from India, UK, US for these major variants coming to Bhutan, or even originating in Bhutan, which is highly unlikely though.
Currently, the positive samples are kept in RCDC but Gene Sequencing is not yet done. The first Wuhan virus, detected in Paro and Thimphu, samples were sent to Bangkok for Gene Sequencing, and during Delta outbreak, the positive samples were sent outside.
WHO recommendation is to continue the current strategies and measures against COVID-19, as there are multiple countries with extensive transmission of new major variants of concern. WHO says data shows that public health and social measures have been effective in reducing COVID-19 cases, hospitalization and deaths.