A fourth dose, boosters for younger kids, masks, and keeping the virus at bay
CLINICAL MATTERS
It is remarkable how fast people forget and move on to other things when there is a perception that the danger has passed. It was barely two months ago when people were bunkered in their homes as the Omicron wave wreaked havoc and cases peaked at nearly 39,000 new infections in one day.
The dramatic decline in COVID-19 cases and deaths is evident in empty isolation beds in hospitals and treatment facilities. Positivity rates are below five percent, and hellish Metro Manila traffic is back. Political rally after political rally with people packed liked sardines shows how reckless people have become, but it isn’t over.
South Korea is showing over 300,000 cases a day at the time of this writing. Vietnam and Germany remain at over 100,000 daily cases. In Southeast Asia, the Philippines is showing the lowest case numbers per million population. Vietnam has surpassed all countries except Indonesia in total case numbers, and Malaysia recently surpassed our pandemic total. This is proof that Omicron is still very much around, and we need both vaccination and masks to defeat it. Thankfully, Filipinos have been very good at wearing masks, and vaccine hesitancy has significantly abated.
What is the best strategy to prevent another spike in cases? Is it safe for kids to go back to school? Do we need a fourth dose of vaccine? There remain many uncertainties on the best way to open safely. At present, it seems the shift to alert level 1 for the first batch of areas is going smoothly. It usually takes two to four weeks before the full impact of mobility change is observed, however, due to the incubation period of the virus and the time delay before someone gets tested. This has always been the difficult part about making policy in real time. The effects of interventions are by nature delayed. It takes time to observe the effects of the policy changes, while the public usually responds to day-to-day case reports, which do not necessarily reflect the most recent guideline changes.
This is the reason the Department of Health has shifted to a weekly bulletin. While the daily case numbers continue to be available on the DOH tracker (https://doh.gov.ph/covid19tracker), the weekly bulletin shifts from an emphasis on daily case numbers to other metrics that capture the societal impact of COVID-19. These metrics include a focus on severe and critical case numbers, the level of healthcare utilization, and the overall vaccination rate. Since severe and critical cases are the ones that can result in hospitalization and death, concentrating on these numbers is a more accurate reflection of the true burden of COVID-19 on our society. This serves as a barometer not just of ongoing transmission but how well our vaccines, masks, and public health standards are continuing to protect our people. Healthcare utilization is self-explanatory since an overwhelmed healthcare system will be unable to take care of the sickest patients who could otherwise be saved. Vaccination rates, including boosters, are reflective of the ongoing effort to provide continuing protection to our countrymen.
With the successful rollout of safe and effective vaccinations, the threat of Covid-19 to our healthcare system has diminished significantly. The availability of effective antivirals that can decrease the risk of dying from Covid-19 by up to 90 percent adds a further safety net. During the Omicron wave, despite record numbers of infections, the hospitals were able to cope. While Omicron is less deadly than Delta, the sheer number of cases would have overwhelmed the healthcare system without the protection of vaccines. The level of vaccination has gotten to a point where lockdowns are no longer necessary to mitigate the impact of even a large spike in cases. Over time and especially with Omicron, vaccine efficacy even against hospitalization declines, and so a booster is necessary, especially for the most vulnerable populations.
While boosters are now standard for those above 18 years old, it has not yet been approved for children. The emphasis on boosters is a result of clear data that protection against hospitalization was significantly impacted during the Omicron wave. While the additional effect of boosters on preventing severe disease for Delta was modest, there was a double-digit improvement in efficacy with Omicron. Recent data shows that even for children, waning immunity in an Omicron-predominant pandemic can be substantially improved with a booster shot. This should be the next step for our vaccine programs. There have been tentative proposals for a fourth dose/second booster shot due to some favorable preliminary evidence from Israel. The increase in protection, however, is quite modest, and the incremental benefit of rolling out the first booster to populations that have not received one outweighs giving a second booster to boosted populations, which continue to have good protection at this time. There also remain many people who have not received their primary vaccine series. These are the ones who most urgently need to be vaccinated as soon as possible.
Face-to-face classes have already started in some schools even at alert level 2. Alert level 1 further expands capacities for returning to physical classes. There is a fierce debate on whether vaccination should be required for children before they are allowed back into the classroom. Since the present vaccines are currently under Emergency Use Authority, it is very difficult to mandate vaccines in this population. As long as a viable alternative to physical classes, however, is in place, schools may be able to mandate them for physical classes to protect the unvaccinated from developing severe disease.
Recent data from the Omicron wave show significant protection against severe disease for vaccinated children compared to unvaccinated ones. More children developed severe disease and died during the Omicron wave than at any point in the pandemic. Since more than 95 percent of the genomes being sequenced locally are Omicron, the unvaccinated children are clearly at risk until they are fully inoculated. Some local government units have already formalized this requirement. From a medical standpoint, this is a sound move to minimize the impact on the children themselves and on the healthcare system at large.
The transition to endemicity entails a leap of faith as people start to resume activities that were previously deemed too risky. Each country has to chart its own path to the new normal. Safety nets and margins of error need to be determined in accordance with local conditions and the willingness of the population to continue following the remaining restrictions. While caution is justified given the number of times the virus has made a comeback, moving forward is necessary to allow people and our country to recover from a virus that has already cost us so much.