Riding on the latest variant Omicron, the COVID-19 cases are surging again. On 13th January, Pakistan recorded over 3000 cases; a 46% increase compared to the previous day. Omicron is a variant that can infect all (the unvaccinated, previously infected, and the vaccinated) but does not cause severe disease in the majority of cases. What is more? The Omicron induces immunity against the Delta variant as well, the reason that Omicron is replacing Delta everywhere.
Scientists are arguing that the exponential rise in the number of infections may render us immune to COVID-19. So, is mother nature going to fulfill through equal distribution of infection what humans could not achieve with the vaccine because of its inequitable distribution? Of course, there are a few caveats too, but let’s first understand the sequence of events that led to the optimism.
Omicron was isolated in South Africa in November 2021. Soon, the South African epidemiologists started reporting high community transmission resulting in a massive wave because of Omicron; over 38,000 new cases every day during its peak in December 2021. Interestingly, the high number of cases did not translate into an equally high number of hospitalizations. Moreover, few needed oxygen and intensive care among those admitted, compared to the past waves of COVID-19 in the country.
Comparing four successive waves of COVID-19, Omicron came out as the most infectious yet least deadly. Today, when the COVID-19 cases in South Africa have declined, the number of Omicron patients needing hospitalizations has been half, and the number of deaths is about 1/5th of what happened during the Delta wave in July 2021.
What could be the reason?
Researchers working with hospital and laboratory data have looked into it. One study found that among the people infected with Omicron (two groups vaccinated with two different vaccines, i.e., Pfizer and Janssen, and a third group having prior infection), the virus could bypass the neutralizing antibodies and cause infection. However, it could not penetrate the second line of defense put up by specialized cells (Lymphocytes type CD-4 and CD-8) and, therefore, could not cause damage to the lung cells.
In another study, also conducted with patients infected by Omicron in South Africa, the researchers found that infection with Omicron caused a 14-fold rise in the protection against Omicron. The infection also caused a 4-fold increase in protection against the Delta virus, the virus’s more dominant and deadlier strain. This capacity of producing immunity against the earlier viruses was not present in the Beta or Delta strains. Because of this characteristic, the deadly Delta variant can be eliminated and replaced by the milder Omicron.
These studies were conducted on a small number of patients coming from limited geography and are up for review. Whether the results can be generalized is yet to be seen. However, Omicron has already sprinted to other countries, supporting the study findings. According to Our World in Data, the current daily infections reported from the U.K. are four times while in the U.S.A., these are double the previous maximum number. Occurring among both vaccinated and unvaccinated, the Omicron (96% in the U.K. and 80% in the U.S.A.) is the predominant strain, displacing Delta.
Since the virus is still surging in these countries, it is difficult to comment on the severity of the disease. In the U.K., where the new cases may be levelling off, the hospitalizations have been 1/3rd while deaths 1/10th of the previous maximum. In the U.S., where 40% of the population is still not vaccinated, hospitalizations are rising steeply in almost all the states; most of those requiring hospitalization are unvaccinated and have other health conditions that increase their risk of severe COVID-19.
So, what do we do during the surge of a virus that has high potential to infect everyone, that causes a mild disease among the vaccinated and previously infected, and whose behavior among the unvaccinated is not fully known yet?
At the individual level, we must ensure that we complete the vaccine schedule according to the age-appropriate guidelines, avoid going into crowds, use facemasks, and ensure that our homes and workplaces are adequately ventilated. Remembering that sore throat and runny nose can be symptoms of Omicron and loss of taste and smell is not characteristic, is important.
At the country level, Pakistan must continue its vaccine rollout, including boosters. Having completed the 2021 target of vaccinating 70 million, Pakistan needs to move on, escalate its targets according to the evolving pandemic, and further enhance its efficiency. In a population of 220 million, and Omicron already surging, we must expect a high number of infections in the coming weeks and prepare accordingly. If the numbers are huge, even a tiny fraction requiring hospitalization can be huge and overwhelm the system.
Infections among health workers are a special concern. In several countries, Omicron has caused massive infections among healthcare workers leading to a considerable drop in their availability. Ensuring that all doctors, nurses, and paramedics in the hospitals and vaccination staff, lady health workers, and other health volunteers in the community setting are fully vaccinated and protected, must be central to the strategy. Alongside, safeguarding a reserve pool of staff in both settings will prevent a breakdown of the system if many health workers go on sick leave because of their infection.
The two big unknowns at the moment are how exactly any population with its demographics will react to Omicron, and how such a contagious virus will behave and mutate (or not) when it spreads through a specific population. The public health experts are watching this massive wave of COVID-19 unfolding before them, with both questions in mind. Everyone is hoping that this tsunami of mild infections brings us to a time when a large majority is immune to SARS-CoV-2, effectively curtailing its transmission, pushing the pandemic to endemicity.
