'Covid Zero' unlikely but Omicron wave could be beginning of the end of pandemic, says top doc

NC Satpathy
As the Omicron variant of Covid-19 surges across India and the world, shattering old records of daily cases, it’s pertinent to know what the road ahead looks like in 2022.
The good news so far has been that Omicron generally causes mild illness and hence the low death and hospitalisation rates. As the new variant appears to affect the upper respiratory tract and spares the lungs, there’s little demand for oxygen and intensive care unit (ICU) beds. But having infected a large number of doctors, nurses and healthcare workers, Omicron has put enormous pressure on hospital manpower. Dr Shamsher Dwivedee, head of the Covid task force at New Delhi’s VIMHANS Niyati Super Speciality hospital, says manpower is the biggest challenge this time.
Going by South Africa’s experience where cases rapidly came down soon after its Omicron-triggered peak, and now that it’s more or less clear that the variant by and large causes mild illness, that brings us to the most interesting prospect:
Is this the beginning of the end ?
Top infectious diseases specialist of California University, Dr Monica Gandhi says, yes, it seems, barring any further surprises, that Omicron will help end the pandemic. She says Omicron is extremely transmissible, resulting in a lot of mild breakthrough infections among the vaccinated (even if boosted). However, Omicron is milder even among the unvaccinated, likely because it can’t infect lung cells very well as shown by multiple studies, starting from one by the University of Hong Kong, to another by the University of College London, and several animal studies. Omicron infection gives broad immunity to the other variants and so a mild breakthrough will boost the immunity of the vaccinated (even to other variants) and give the unvaccinated immunity to Covid-19, if exposed. So, she says, unless we have a new variant that is more virulent or evades immunity, it looks like Omicron will be the variant to get us from the pandemic to the endemic phase.
But not all are so optimistic. Pune-based immunologist Dr Vineeta Bal says until there is a large population with immunity to coronavirus that exists globally, the pandemic will not go away. Globally, children are still not vaccinated. Thus, it will be a short-sighted prediction to think the pandemic will go away soon, says Dr Bal.
Dr Dwivedee says “less severe disease” is a relative term. Mild or severe don’t matter as Covid can cause blood clots and strokes. In the winter months, heart attacks are common. So people with high blood pressure and diabetes are vulnerable.
Why are mask mandates important ?
Dr Dwivedee says even if Omicron is causing mild symptoms in younger people, they must wear masks. This is just to protect the older lot who are vulnerable. Even though Omicron will continue to infect a large number of people, masks will help reduce the viral load, making the disease less severe.
Do vaccines work against Omicron and what about new variants ?
Dr Gandhi says yes, vaccines do work against all variants. Our response from vaccines (and why we see mild infections even when vaccinated) is likely due to the antibodies versus the B and T cell response. Although antibodies (our main line of defence for upper respiratory tract symptoms e.g. mild breakthroughs) can wane over time or be affected by mutations along the spike protein like with Omicron, we know now that T cells from the vaccine still work against Omicron and B cells (generated by the vaccines) adapt the new antibodies they produce to work against variants. Therefore, the protection conferred by the vaccines against severe disease (but not mild breakthrough infections, even with the booster) seems to be holding up very well, says Dr Gandhi.
According to Dr Gandhi, new variants will continue to emerge but T cell immunity is robust and provides an in-breadth response across the spike protein, so our current vaccines will suffice. So we won’t need new vaccines every time.
Dr Vineeta Bal says pre-existing immunity, whether due to infection or vaccination, will provide adequate protection from new variants.
How effective are lockdowns ?
Dr Dwivedee says cases of Covid patients getting admitted into hospitals are rising by the day and the fast Omicron surge could overload hospitals very soon. He says there may not be scientific logic behind lockdowns but they certainly slow down the speed of the spread and in turn help the healthcare system as they are not stretched beyond the limit. He says going by the scale of the Omicron infection, if a small percentage of the unvaccinated population gets infected and some of them need hospitalisation, it would make a significant impact on the hospital workload. Here, the lockdowns help as they limit the spread and hence reduce the burden on hospitals.
To sum it up, as Governments across the world scramble to change Covid strategies to live with the virus, Dr Gandhi says it’s important to note that for a variety of reasons, including the presence of animal reservoirs, the long infectious period, the failure of vaccines to provide sterilising immunity, and the fact that Covid resembles other respiratory syndromes, “Covid zero” is not achievable. However, even without elimination, we can still control Covid-19 and we are getting closer to that point. The key to that is complete vaccination of the eligible population and also getting children vaccinated in quick time.       News 18