CLINICAL MATTER
We all woke up last week to the announcement that the World Health Organization (WHO) has determined that the emergency phase of the pandemic is at an end. Despite this determination, the occasional upticks in case numbers continue to sow anxiety among our traumatized populace. The significant increase in cases in the last two weeks has not even approached the case numbers of Delta and Omicron, and yet several schools have declared a pause to face-to-face classes. Coupled with alarmist news reports and an unhealthy obsession with obsolete positivity rate metrics bandied about by pseudo-experts, these knee-jerk reactions cause more harm than good.
The Department of Health (DOH) no longer puts much stock in absolute case numbers or positivity rates. Since more than 70 percent of the populace has been vaccinated, the vast majority of Covid-19 cases are expected to be mild. None of the subsequent spikes in cases since the Omicron wave in January 2022 have significantly increased hospitalization rates or deaths. Nationwide metrics for healthcare utilization remain below 20 percent and there is no risk of hospitals being overwhelmed by the increase in incident cases.
I recall that at the height of the Delta wave in August 2021, I had up to 60 patients admitted under my service in the hospital on any given day. Some doctors took care of over a hundred inpatients each day. The waiting lists for hospital rooms in the ER ran in the hundreds, and many very sick people could not find a place to go. During the BA.2 Omicron wave in January 2022, there were paradoxically fewer hospital admissions compared to Delta, despite nearly double the number of confirmed cases. This is the desired effect of widespread vaccination, a phenomenon known as “decoupling,” where the number of deaths is no longer proportional to the number of cases.
Despite the increased mobility and in spite of the entry of new Omicron sublineages, the number of daily cases never surged past 4,000 for the rest of 2022. This trend continued even after we held national elections. The number of daily cases has not gone beyond 2,000 cases since the start of 2023. Moreover, in that time frame there have been less than 10 deaths a day (not counting backlogs), with zero reported deaths so far since the start of March 2023.
Officially captured testing numbers have fallen off due to less RT-PCR testing and more antigen testing. Only RT-PCR tests are counted in the official tally. Nevertheless, there is a high probability that suspected severe cases and deaths from Covid-19 will still be tested via RT-PCR and captured since these patients will require medical attention. It is unlikely that sicker patients are being missed. This phenomenon is also one of the reasons the positivity rate is no longer a good metric for determining risk. Cases that are tested with RT-PCR are more likely to be symptomatic and present for formal medical care, which also means they have a higher overall chance of testing positive. Hospitals have stopped routinely testing asymptomatic admissions, and so the denominator of total number of tests is now smaller, leading to bigger fluctuations in positivity rate.
Given the low likelihood that even having a high number of Covid-19 cases will cause a proportionally large number of severe cases, the DOH has opted to continue the process of reopening the economy by further relaxing restrictions and making masking voluntary. The effect of the relaxation of restrictions is logically a rise in cases since there are fewer barriers to infection. The smaller percentage needing hospitalization will be manageable and will not lead to renewed restrictions. It is therefore counterproductive to reinstate restrictions in response to an expected increase in cases when there is no clear threat to the healthcare system.
Locking down schools when there is a cluster of cases is not sustainable. Most of these cases will be mild, and shutting down a school because of a spike in cases causes more harm than good in terms of school and workdays missed. Online classes are clearly suboptimal, and our students are already far behind. As long as most students and teachers are vaccinated, physical classes can safely continue. Management can opt to increase protection from infection by asking students and teachers to wear masks inside classrooms as much as possible for at least two long incubation periods (typically 28 days total) whenever there is a clear clustering of cases instead of shutting down the campus. As Covid-19 becomes endemic and seasonal, there should be fewer disruptions to classes and work since these small outbreaks will be mild and predictable. Improvements in occupational safety, including better ventilation and air quality monitoring will go a long way in decreasing the likelihood of a severe breakout.
What about further boosters and bivalent vaccines? The latest WHO advice has taken a step back from aggressive boosting. Reviewing the best available evidence, WHO has recommended that second boosters are only necessary for the highest risk populations such as the elderly, immunocompromised, adults with comorbid conditions, and frontline health workers. Classified as medium risk and only needing one booster are healthy adults as well as children with comorbidities. Second boosters are safe and can be given for the medium risk population but WHO does not require them since the additional benefit is very small. Finally, the low risk group, which includes healthy children and adolescents aged six months to 17 years may need only the primary series. While boosters are safe in this population, there is little evidence that there is significant incremental benefit from a public health standpoint.
The WHO recommendations stand in stark contrast with the US CDC recommendations, which state that anyone above the age of six months should get a bivalent booster at least two months from the last monovalent vaccine dose, regardless of how many monovalent vaccine doses they have received. This recommendation is based on the observation that the bivalent vaccines do have somewhat better efficacy against symptomatic infection and hospitalization, especially in the higher risk population.
I believe there is value to the added protection from bivalent vaccines, especially for our most vulnerable populations. It is likely that the Philippines will adopt a middle ground between the WHO and CDC recommendations. Since bivalent vaccines are still in short supply, stocks that can be procured should be offered to the highest risk populations as defined by WHO. Medium and low risk groups may follow in the future once there is adequate vaccine available, and if better evidence comes to light. Whatever the final path we take, we already know that even without further boosting, vaccines have done their job. Covid-19 is on its way to endemicity, and we should get on with our lives.