Who are most protected against the Delta COVID variant?
The sudden surge of COVID-19 cases in the past and the emergence of new variants time and again indicate the unpredictability of the SARs-COV-2 virus. The B.1.617.2 variant of coronavirus, also known as the Delta variant has been categorized as a Variant of Concern (VoC) and is said to have driven India's second wave. While the country returns back to a state of normalcy, scientists and medical professionals continue to look into the many layers of COVID variants in order to gear up for a potential third wave.
Why is the Delta COVID variant concerning?
The Delta variant carries the genetic code from two other mutations, E484Q and L452R, which is why it becomes all the more easy for it to break into the human immune system and invade the organs. Additionally, as the new variants tend to alter the structure of the spike protein, it is more efficient in attaching itself to the human host cells and multiplies swiftly, doing more damage than an originally COVID strain.
Who is most likely to be protected against the Delta variant?
While non-vaccinated/partially vaccinated individuals and people with pre-existing comorbidities are at a greater risk of developing the Delta variant, a recent study reveals the list of people who may be protected from the variant of concern.
According to the study conducted by the researchers from the Indian Council of Medical Research, National Institute of Virology, Department of Neurosurgery, Command Hospital (Southern Command), Armed Forces Medical College, Pune, recovered COVID patients who have either received one or both their COVID shots (Covishield) have maximum protection against the Delta variant of coronavirus.
The study
The study took into account immune responses of 5 categories of people.
- One dose vaccinated
- Two doses vaccinated,
- COVID-19 recovered plus one dose vaccinated
- COVID-19 recovered plus two doses vaccinated
- Breakthrough COVID-19 cases
As per the study, breakthrough cases and recovered COVID-19 patients who have either received one or two doses of vaccine have relatively higher protection against Delta variant as compared to those who have never been infected and are fully vaccinated.
The study said, "Prior vaccination results in less severe disease against subsequent infection provide evidence that both humoral and cellular immune response play an important role in protection."
How effective are the vaccines against the Delta variant and other COVID strains?
As per the ICMR study, "The worldwide endeavour of scientists to create a safe and effective COVID19 vaccine has resulted in the availability of 18 vaccines, which have received Emergency Use Authorization. The vaccines available against SARS-CoV-2, have shown efficacy ranging from 51 % to 94% against the original strain D614G in phase 3 clinical trials. Immune response to SARS-CoV-2 infection involves innate immune activation and antigen-specific responses of B and T cells. Particularly, the questions about the immune escape of, newly emerging VOCs in vaccinated individuals are still being explored. For example, the efficacy of AZD1222, which was reported to be 70% in the UK and Brazil, only reached 22% in South Africa."
Althought the government has asked COVID-recovered patients to defer vaccination from 3 months, the study suggests that natural protection can be made greater by even one dose of vaccine against the Delta variant.
"Long-term follow-up of participants could help understand the impact of natural infection and vaccination on long-term protection from SARS-CoV-2 offered by Covishield. It is important to track the breakthrough infections to look for unexpected changes. Monitoring of breakthrough infection would make us understand the impact of new variants or VOC on the escape of vaccine-induced immunity. Data has shown again and again that if the individuals get infected post-vaccination, they have been protected from severe disease," the study added.
Things you can do to protect yourself from new COVID variants
Practice COVID appropriate behaviour and double mask whenever needed. Above all, get yourself vaccinated. Vaccination is the only way to gain some immunity against the infection and/or to reduce risk of severe infection.