Dr. Juni Banerjee, Neucrad Health Desk, June 4, 2021
While India managed the first wave of Covid-19 pandemic last year pretty well, the presence of Immune-Escaping Coronavirus variants and several undisciplined hectic gatherings all around the country have completely derailed the managed-pandemic this time of the year! In fact, India is witnessing the most severe form of Covid catastrophe and spike in infections and deaths like never before currently. Let’s understand how these variants are one of the leading reasons for the same!
The SARS-CoV-2, supposedly to mutate slowly, has reflected many peculiar characteristics by changing its sequences and giving rise to several variants and lineages.
- B.1.617, a ‘double mutant’ virus (containing 2 mutations namely E484Q and L245R) with a high transmission rate was interestingly detected in more than half of the sequenced genome sample cases of Maharashtra last year.
- However, the suspected force behind the second wave has been identified as a new variant called “B.1.618”.
- India has reported 62.5 percent of the B.1.618 variants in the world, as per current analysis on the outbreak.info.
- Scientists have reported that the cases of B.1.618 infections are particularly high in West Bengal. However, members of this lineage virus have been detected from other parts of the globe like the US, Switzerland and Singapore too.
- Of note, even if a person has previously been infected by the coronavirus and has the ability to produce antibodies against it, B.1.618 has the ability to still escape that person’s immune response!
- B.1.617, a ‘double mutant’ virus (containing 2 mutations namely E484Q and L245R) characterised by a combination of multiple mutations—deletions of tyrosine and histidine amino acid at 145 and 146 positions of the spike protein.
- The reasons behind the severity and immune escaping properties of B.1.618 involves a) the E484K mutation that is linked to dodging immune response and b) the D614G mutation that contribute towards increased infectivity. Interestingly, E484K mutation has been indicated as a reason for failing the plasma therapy in Covid treatment!
- At present, B.1.618 is highly contagious and scientists estimate that this variant is responsible for the deaths of most Covid-19 patients.
However, the scientific world still needs to find out few facts about this immune escaping variant like:
- if this variant causes the virus to re-infect or not,
- The precise nature of the virus’s transmission- the transmission mechanism in the bodily cells.
- Also, the effectiveness of the vaccines against this “double-mutant” variant. The problem is that vaccination has not yet begun full-fledgedly across India in proportion to the rate of infection spread.
Let’s not forget that further waves of the Covid-19 pandemic are supposedly be arriving or have already been arrived in many places, the following things needs to be focussed:
- Hectic Crowd gatherings should be avoided at any cost!
- The scientific community needs to study the mutation characteristics of the virus as well as the efficacy of vaccines against the newer variants.
- As newer and newer immune escaping variants of the original strain are appearing, the hope for herd immunity (that holds true for the same virus) is getting faded. Since, vaccines reduce the risk for a person to get covid-19 via producing antibodies against the SARS-CoV-2 as well as destroying the virus, vaccines do ensure the person does not fall ill if further exposed to the virus. Even though vaccines cannot guarantee 100% safety, getting vaccinated is the best possible way to be safer in this covid catastrophe right now.
- Moreover, the Head of Epidemiology and Communicable Diseases at the Indian Council of Medical Research (ICMR) has said that “time tested proven prevention strategies should be strictly adhered to such as correct and consistent use of face mask, maintaining hand hygiene, maintaining physical distancing, and avoidance of mass gatherings should be adhered to”.
- The countries should give full priority towards their health facilities, availability of hospital-beds, ventilators, oxygen concentrators, medical staffs, PPE kits, medicines, etc.
- Di Caro A, Cunha F, Petrosillo N, et al. Severe acute respiratory syndrome coronavirus 2 escape mutants and protective immunity from natural infections or immunizations [published online ahead of print, 2021 Mar 29]. Clin Microbiol Infect. 2021;S1198-743X(21)00146-4. doi:10.1016/j.cmi.2021.03.011
- Garcia-Beltran WF, Lam EC, St Denis K, et al. Circulating SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity. Preprint. medRxiv. 2021;2021.02.14.21251704. Published 2021 Feb 18. doi:10.1101/2021.02.14.21251704
- Fontanet A, Autran B, Lina B, Kieny MP, Karim SSA, Sridhar D. SARS-CoV-2 variants and ending the COVID-19 pandemic. Lancet. 2021 Mar 13;397(10278):952-954. doi: 10.1016/S0140-6736(21)00370-6. Epub 2021 Feb 11. PMID: 33581803; PMCID: PMC7906631.