KK Talwar
Former Director, PGIMER, Chandigarh
The Covid-19 pandemic has taught us many lessons, an important one being the vital significance of adopting an evidence-based approach for prevention and management. The Omicron variant, being airborne, is highly infectious. It appears comparable to measles as a benchmark for transmissibility. This highlights the importance from a preventive standpoint of strict adherence to Covid-protective behaviour — proper use of masks, avoiding crowded places and hand sanitisation. These simple practices can be effective ‘social vaccines’. While using N95 masks gives the best protection, even double-masking with a cloth and a surgical mask appears to provide sufficient protection. Of course, proper use of masks is most important — the mask must fit snugly, covering both the mouth and the nose. Improper use of the mask defeats its purpose.
As regards treatment and management, medical protocols must also be based on evidence, comprising medication and practices which benefit the patient while minimising the adverse side-effects. Following management guidelines of the Ministry of Health, which are based on scientific evidence and analysis by the experts, is highly advisable. Drugs like Chloroquine, Ivermectin and Favipiravir, which were being used without definite data or evidence in support, have rightly been dropped. Steroids have been shown to be extremely beneficial in moderate to critical Covid patients, and to improve the chances of survival. However, their injudicious use led to serious adverse consequences, including diseases like mucormycosis.
The antiviral Molnupiravir, which was approved for use just before the current wave should be limited to mild or moderately symptomatic immunocompromised patients and not be mechanically prescribed and administered to all patients. It must also be borne in mind that there is no data so far documenting its safety in relation to chronic kidney and liver diseases, and in regard to its use in vaccinated individuals. Unfortunately, despite warnings from the ICMR regarding its serious side-effects, it is also being injudiciously used by the medical practitioners.
Similarly, the monoclonal antibodies currently available in our country have been shown to be ineffective against the Omicron variant. Yet, their use continues. The only monoclonal antibody which is effective against this variant (Sotrovimab from GSK) is not currently available in India.
Data regarding transmission indicates that transmission is at its peak a day or so prior to onset of symptoms and two to three days thereafter. By the end of five days, the virus shedding drops sharply. It is for this reason that the guidelines now provide for isolation for a period of seven days, as opposed to 14 days earlier. In countries like the United States of America, the period has been shortened to five days. Of course, proper masking even after this period is important to prevent further spread.
The concern is mainly about the more vulnerable sections, i.e., those with comorbidities. A big challenge with this variant being its highly transmissible nature, there is increased likelihood of persons with comorbidities getting infected. The infection often leads to a worsening of the underlying conditions/diseases, viz, chronic kidney, liver, cardiac diseases and cancer. This in turn, necessitates hospitalisation. It is important, therefore, to protect such people from infection, and to ensure optimal treatment for the basic ailments. It is advisable for persons with comorbidities to use masks even at home, to avoid possible exposure from undetected asymptomatic Covid-positive family members. There is a reluctance to visit the hospital during the ongoing wave for managing the comorbid conditions. However, it must be appreciated that delay in seeking medical help can often have irreversible consequences. Teleconsultation can be a helpful method in some cases, but is no substitute in cases where physical examination or clinical investigations are necessary.
In order to effectively address such cases, hospital policies and protocols also need to be updated. Currently, most hospitals admit patients and keep them in a ‘suspect area’ while their Covid test is carried out and the report obtained. This practice delays medical care to the patient and ends up acting as a disincentive for hospital admission. RT-PCR Covid test reports taken 6-8 hours early are the best situations, and while TrueNat and CBNATT tests are faster, they are significantly more expensive. These issues need to be addressed urgently so that timely care is made available to the admitted patient without waiting for the Covid test report, thereby preventing further deterioration in the patient’s condition or even mortality.
The government has made tremendous efforts to manage the pandemic. Together with hospitals and other scientific institutes, it must continue to address issues as they arise. The environment is dynamic and ever changing, and our response must continuously evolve accordingly. Thus, while the third ‘precautionary shot’ is a welcome step, we must put in place all necessary measures to maximise its success. To this end, a scheme of ‘home vaccination’ for the elderly or those who resent coming to hospitals for fear of exposure should be seriously considered, so that the commendable vaccination effort truly achieves its objectives.
There is, to all this, a silver lining. Clinical evidence and experience since the beginning of this wave indicate low virulence of the Omicron variant. There is far less involvement of the lungs in the infection, and the virus appears to replicate more in the upper respiratory airways. Consequently, hospital admissions and mortality are also less, compared to the earlier Delta and other variants. The existence of an immune response, and prior vaccination, may also be relevant factors. As the third dose of the vaccine is rolled out, immune protection from serious diseases will further increase. Some preliminary scientific data also suggests that immunity derived from the Omicron variant protects against Delta and other known variants. The existence of immunity in a large section of the population should seriously limit the ability of the virus to spread, and could well end up bringing about the ‘herd immunity’ that scientists have been speaking of. If Omicron becomes the most dominant strain, we could well witness the transition of Covid-19 to a less dangerous disease. Of course, a lot depends on whether any more virulent variant of the virus emerges or not. Let us hope that God is kind.