Lt Col Nazmul Huda Khan:
Global deaths from the Covid-19 virus amount to approximately five and half million. The surge in the Omicron variant suggests that the pandemic may be more prolonged necessitating booster doses and strict compliance with public-health measures. World is approaching the third year of the globe’s collective experience with the SARS-CoV-2 virus and the Covid-19 pandemic it has triggered. At this point, the scorching queries amongst the habitants of this planet are: When and how will this pandemic end?
There may have been a lot of guesses and suppositions or dilemmas regarding the time frame of end of the existing pandemic those probably sound dismal, but don’t despair. The truth of the matter is that pandemics always end. The viruses that caused pandemics underwent a transition. Our immune systems learned enough about them to fend off the deadliest manifestations of infection, at least most of the time. Humans and viruses have reached an immunological detente. Instead of causing tsunamis of devastating illness, over time the viruses came to trigger small surges of milder illness. That’s a phenomenon by which a pathogen stops spreading because so many people are protected against it, because they’ve already been infected or vaccinated.
The coronavirus continues to rip much of the world through developing new mutations and variants that making vaccines less effective. Almost thirty crore of the global population have been infected so far and many poor countries aren’t expected to have widespread access to vaccines until 2023. In this context, epidemiologists say, it is hard to predict how long immunity from prior infections and vaccinations will last. In a survey by the magazine Nature, nearly 90 percent of immunologists, infectious-disease researchers and virologists believe that the disease will become endemic and circulate in pockets of the global population for the foreseeable future.
There are growing evidences that vaccines are effective. The vaccine rollout is also improving in most of the countries. Moreover, vaccine trials on children aged 12 and up are well underway; new trials on babies and children of six months and older raise the possibility of pediatric vaccination which would add to the population that could potentially contribute to herd immunity. A new wave of Covid-19 therapeutics suggests that they have the potential to materially reduce hospitalizations and accelerating a transition toward normalcy. But it is a matter of concern that new infectious variants of concern like Omicron, Delmicronetc may drive a new wave of cases in the coming months.
Few factors may also cause delay toward normalcy and increase additional risk in herd immunity. Among those- first, vaccine adoption may prove lower than expected. Second, herd immunity relies on the efficacy of vaccines at reducing transmission. Third, the duration of vaccine-mediated immunity may prove shorter than anticipated. Fourth, supply-chain disruptions and delays. Fifth and most concerning are the variants those reduce the efficacy of vaccines or the benefits of natural immunity may spread widely.
It is obvious that, continued improvement of public-health interventions those don’t significantly limit economic and social activities; compliance with public-health measures; accurate, widely available, rapid testing that effectively enables specific activities and continued advancements in therapeutics and clinical management of Covid-19, leading to lower infection-fatality ratios will also contribute to the transition to a form of normalcy – the more of these that are achieved, the faster the milestone is likely to be reached.
Considering all such compounding factors researchers and scientists are predicting that the Covid-19 will come to an end, may not in the state of elimination or eradication. The end might look like that some nations may possess nationwide herd immunity. This scenario is most likely in smaller countries where immunity to Covid-19 can become uniformly high. Some regions, states, or cities may obtain regional herd immunity where people are well protected. A population or region may achieve herd immunity for some period, but if new variants are introduced, against which prior immunity is less effective, a new wave of cases may be launched. Some countries or region may fail to achieve herd immunity, likely in places where vaccine access is limited, where few people choose to be vaccinated, if the duration of immunity is short, or variants that reduce vaccine efficacy are common and widespread.
The UN health agency chief recently expressed optimism during a press briefing on 29 December 2021 Wednesday that, 2022 maybe the year the world ends the acute stage of the Covid-19 pandemic.? He was highly concerned that the more transmissible Omicron, circulating at the same time as Delta is leading to a tsunami of cases. The Director General of WHO Mr Tedroshas asked for equity and solidarity for supply of health tools, including masks, therapeutics, diagnostics and vaccines to all countries yet needed to create the ideal conditions for the emergence of new variants.
It is obvious that a premature planning to return to pre-pandemic life may risk more cases and more deaths. The new variants are much more transmissible than all previous variants are already spreading around the globe. Pursuant to experts and researchers and world leading health agencies, the third wave of Covid-19 can be more deadly if we prematurely relax our protections.
(Lt Col Nazmul Huda Khan, MBBS, MPH, MPhil, Assistant Director, Kurmitola General Hospital. [email protected])
