The virologists and health experts have  said that it is unlikely that anytime soon, we will enter into pre-Covid era. Instead, it is likely that we will have to co-exist with Delta and Omicron variants in time to come. They concurred that both these variants will continue to co-circulate and underscored the importance of kids vaccination, same shot booster doses and RT-PCR tests.

Vaccinate children quickly 

Dr.  T Jacob John, Former Director, ICMR’s Centre of Advanced Research in Virology, Retired professor and Head of the Department of Clinical Virology and Microbiology at CMC Vellore emphasized on vaccinating children quickly to minimize the virus transmission and risk of emergence of new variants by mutations.  He says, “I am an ardent advocate of children’s vaccination with vaccines which are safe and effective, for example Covaxin. The risk of disease/death is low but not zero even in normal children. Post-infection they are at risk for multi-system inflammatory syndrome (MIS) and for diabetes — Children with chronic diseases are at high risk of COVID itself — all these are prevented by vaccination. If children are left unvaccinated, they will act as a virus reservoir, and  we know that Omicron infects children quite readily”.

He added, “Omicron has two significant properties. One, it has extremely high transmission efficiency, far more than that of Delta, and its propensity to evade immunity induced by past infections and vaccinations. These properties are conferred by a large number of mutations on its spike protein gene.

While Delta has two mutations on the receptor-binding domain of the spike protein, Omicron has 15. This has resulted in evasion from antibody binding, necessary for protection. Neutralising antibodies against the spike protein of the original virus, induced by all available vaccines (mRNA or adenovirus-vectored) are relatively ineffective against Omicron. However, recent experience shows that very high levels of antibodies that result from booster doses offer protection, especially from severe disease needing hospitalization.”

Using the same dose vaccine as a booster is best 

Dr.  V. Ravi, Former Professor of Neurovirology at NIMHANS and Nodal Officer for genomic confirmation of SARS-CoV-2 Government of Karnataka, said, “Self-test kits viz. antigen tests give reliable results in symptomatic patients; however asymptomatic patients must undertake RT-PCR tests for results especially when there is a huge surge in cases.” He remarked that current data shows that Omicron is seen more in double vaccinated people thus it is in our best interest that we don’t let our guard down.

He added, “It is wrong to expect that Covid-19 vaccine should provide us with sterilizing immunity and protection. Their primary function is to prevent severe disease and deaths. Nasal vaccines are showing tremendous amount of promise. I am sure these will provide reasonable amount of protection when availed in the market.”

On mixing of two different vaccines, he said, “There is no clear-cut data on mixing of vaccines in India. Thus, our current policy on using the same dose vaccine as a booster is in our best interest.”

Dr. V. Ramasubramanian, Consultant Infectious Diseases & Tropical Medicine, Apollo Hospitals, said, “There has been an increase in youngsters coming in with high fever even in comparison to the Delta variant where the age of infection was already significantly lowered. The age limit now has been further lowered to 5 to 6 years where a temperature of 102 to 103 degree has been recorded. Interestingly, either their fever settles within 24 hours or within 4 to 5 days. These all cases are symptomatic, and they are responding to the treatment. Besides fever, they are reporting a severe throat pain. Most of them are not in condition to even swallow food. We have noticed that due to high fever and throat pain, the consumption of antibiotics has gone up in last few weeks.”

increase in test positivity rate (TPR)

Dr. Saranya Narayan, Technical Director and Chief Microbiologists, Neuberg Diagnostics, said, “At our lab in Chennai, we have noticed an increase in test positivity rate (TPR) since December 28, 2021. Between December 25 and January 10, out of 19,558 Covid-19 tests, TPR was 27.2%. Out of these positives, 11% were in the under 18 age group. Infections are now being recorded in the 1 to 10 years age group too . In infants under one year, two tested positive.

Weekly TPR in our lab in Bengaluru has gone up from 5.3 to 20.6 %. In our Chennai lab, from December 28 until 11 January, weekly TPR has increased from 11.1 to 34.7%. Similarly, in our Kerala lab, weekly TPR hovers around 8.41 with an increase in the last couple of days in the daily TPR. In Hyderabad, the daily TPR is around 45 % while in Mumbai ( Maharashtra) it is around 40%.”

Regarding Omicron positivity, she added, “Karnataka has 50% positivity ratio, Mumbai has 40%, Hyderabad has 45% and Tamil Nadu has 80-85%.”

Experts echoed that everyone must strictly adopt personal prevention measures, double masks, observe hand hygiene, keep good ventilation indoors and avoid crowds and non-essential travel.

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Key highlights

• The Elecsys Anti-SARS-CoV-2 S quantifies immune response in an individual and determines the exposure status to SARS-CoV 2
• The test  targets antibodies against the spike protein and plays an important part in characterising a vaccine-induced immune response ¹
• Moderna’s mRNA vaccine trials includes Elecsys Anti-SARS-CoV-2 S test to assess the correlation between protection from vaccination and antibody levels
• The Elecsys Anti-SARS-CoV-2 S assay has an excellent correlation with the WHO International Standard.²

Mumbai: Friday, 22 January 2021: Roche Diagnostics India announced the launch of its antibody test SARS-CoV-2 test – Elecsys Anti-SARS-CoV-2 S. The test is CE IVD approved and has received ICMR and CDSCO approval in India. It is an in vitro test, that quantifies antibodies against the receptor-binding domain (RBD) of spike (S) protein SARS-CoV-2 in human serum and plasma, and determines the body’s immune response to the virus.

The Elecsys Anti-SARS-CoV-2 S targets antibodies, which are directed against the particular region of the viral spike protein responsible for binding to the host cell receptor, which is required for the virus to enter the host cell.³ The majority of current vaccines (approved and in development) aim to induce antibody response against the viral spike protein.

Narendra Varde, Managing Director – Roche Diagnostics India, said, “Roche is firmly committed to providing reliable, high-quality testing solutions to help the country deal with the pandemic. The newest antibody solution, Elecsys Anti-SARS-CoV-2 S,  will not only give a ‘positive’ or ‘negative’ result, but also will provide a numerical result to indicate the concentration of SARS-CoV-2 specific antibodies in the blood, further supporting the healthcare systems and patients as we jointly fight COVID-19.”

Dr. Sandeep Sewlikar, Head of Medical & Scientific Affairs – Roche Diagnostics India, pointed out the need for an antibody test for India by stating: “The test has both a high clinical specificity of 99.98% (N=5991) and sensitivity of 98.8% (N=1423), 14 days or later after diagnosis with PCR. The result is provided in the form of an antibody concentration (U/mL). The units of the Elecsys Anti-SARS-CoV-2 S assay have an excellent correlation with and can be considered equivalent to the units of the WHO International Standard.²”

In vaccine trials, before a vaccine is administered it would be beneficial to know the starting level of antibodies a person has, in order to evaluate any change in antibody levels that the vaccine induces, especially the development of antibodies directed against the SARS-CoV-2 spike protein. These antibodies have been shown to have potent antiviral activity and correlate to potential immunity.⁴ 

Globally, Roche Diagnostics partnered with Moderna, to utilise the Elecsys Anti-SARS-CoV-2 S antibody test in the mRNA-1273 vaccine research trials. The test will help Moderna establish a correlation between vaccine-induced protection and levels of antibodies.

Alongside its importance to vaccine efficacy evaluations, the Elecsys Anti-SARS-CoV-2 S serology test can be used to determine antibody levels in plasmapheresis donations and for estimating seroprevalence.

The Elecsys Anti-SARS-CoV-2 S immunoassay runs on Roche’s widely available cobase analysers, and these fully automated systems can provide SARS-Cov-2 test results in approximately 18 minutes for one test, with a test throughput of up to 300 tests/hour, depending on the analyser.⁵    The test is the latest addition to the comprehensive Roche diagnostic molecular and serology portfolio to help healthcare systems combat COVID-19.

References

1. Zhu FC et al. (2020). The Lancet 396:479 – 4882)
2. Roche data on file
3. Hoffmann, Markus et al. (2020). Cell. 81(2):271-280.e8;
4. Masters PS (2006). The molecular biology of coronaviruses. Advances in Virus Research. Academic Press. 66: 193–292;
5. Full specifications of the Roche immunoassay systems, including throughput, can be found on our diagnostics. roche website

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