CLINICAL MATTERS

Three years ago, any cough or cold symptoms generated a lot of anxiety, dread, and panic since there was a big possibility it was Covid-19. Prior to the discovery of effective treatment and widespread vaccination, the risk of dying from Covid-19 could be as high as 10 percent, especially among the elderly and those with comorbid conditions. I remember thinking that I might die when I first developed a sore throat in March 2020 after taking care of some of the first Covid-19 patients. Fortunately, I tested negative. Several of my medical school professors did succumb to SARS-CoV-2 early in the pandemic because we really didn’t know how to treat Covid-19 properly. With the advent of vaccination and potent interventions, we have weathered that storm. Mortality rates from Covid-19 among vaccinated patients are consistently lower than one percent despite the emergence of new variants, and this can be further decreased with antivirals. Why then are some people still wearing masks? And why are some schools moving to online classes when respiratory infections increase?

The Covid-19 pandemic gave us a much better understanding of how respiratory viruses spread. It also taught us a lot of lessons on how to prevent viral transmission. One beneficial side effect of wearing masks and adhering to public health standards is that it significantly decreased the risk of getting other respiratory viruses such as influenza and respiratory syncytial virus (RSV). Unfortunately, this also meant that population immunity to these viruses went down, and so we were due for a spike in cases as we opened up. This was very evident in the US in the fall of 2022 when they had a “tridemic” of Covid-19, flu, and RSV as they completely did away with masks. RSV was particularly deadly to young children and many had to be hospitalized, of which a significant number died.

The safest and best way to prevent these kinds of spikes in respiratory illnesses is by boosting immunity through vaccination. While there is a readily available vaccine for influenza, the uptake has not been ideal. RSV vaccines have just been approved in the US and are only about to come to market locally. While the current increase in respiratory illnesses is expected, these spikes may be easier to mitigate in the near future if an aggressive vaccination and masking campaign is initiated prior to the expected peak of illness.

I still get several messages every week about what to do when someone gets a cough or cold nowadays. Is it still worth it to test for Covid-19 or just assume that it is the flu? The answer is that it depends. If someone is in the high-risk population and can benefit from treatment with antivirals, then testing with a Covid-19 antigen test and even an RT-PCR can be quite useful. Those who remain unvaccinated for Covid-19—either by choice or those who were too young to get vaccinated—should definitely get tested when they develop symptoms in order to understand their risk for hospitalization and potential for development of severe disease. Covid-19 testing can also be useful to prevent exposure of more vulnerable household contacts and to guide isolation. Repeat antigen testing can shorten isolation duration, although one should continue to wear a mask until symptoms have completely resolved. Covid-19 testing if negative can help point to other viral causes of respiratory symptoms such as influenza which can then be tested and treated with antivirals. 

Routine testing is no longer recommended for fully vaccinated, asymptomatic individuals even if they have probable Covid-19 exposure, as this has a minimal impact on transmission and management. Hospitals have since stopped routinely testing patients for hospital admission if they do not have respiratory symptoms since this is no longer cost-effective and can give rise to false positives among those who have recently recovered from Covid-19 infection. One option for symptomatic individuals aside from a standalone Covid-19 test (antigen or RT-PCR) is a respiratory PCR panel that not only detects Covid-19 but also RSV and influenza. These panels tend to be expensive, however, and are best reserved for those who have more severe symptoms and may need hospital admission. Newer multiplex antigen tests that simultaneously detect SARS-Cov-2, RSV, and influenza have been developed and may be cheaper and easier to use in our local setting if they become available. Since there are available effective antivirals for Covid-19 and influenza (and, with hope, soon for RSV as well), there is real value in determining what virus is present, especially for high-risk individuals.

In the meantime, notwithstanding test and antiviral availability, masks continue to be useful tools for interrupting transmission. You don’t always need an N95 mask to benefit from this intervention as surgical masks prevent a significant amount of transmission and are much more affordable and tolerable. You also don’t need to constantly wear the mask if you aren’t high risk. The best times to wear a mask are when cases are high, when there is poor ventilation, and in crowded indoor settings. As long as you are fully vaccinated and boosted and you are not in the high-risk population, it is unlikely that you will get severe disease and die from breakthrough Covid-19 infection. Some compelling reasons to continue wearing a higher quality mask are if you live with high-risk persons or if you work in the healthcare field, where you can transmit virus to sick patients in the hospital. Otherwise, risk-based and rational use of masks as appropriate is acceptable.

As for shifting to online school when cases are high, I do not think this is warranted anymore. Online school has been shown to be suboptimal, and school-age kids are at low risk for poor outcomes from breakthrough infection as long as they are healthy and vaccinated. Judicious use of masks in schools when cases are spiking will help mitigate secondary infections, along with a strict policy of staying home for those who are symptomatic.

At the end of the day, we do need to move on from a pandemic mindset. But there is one thing that does make me keep my mask on for a bit longer even if I am technically not at risk for severe disease. I call it the “yuck” factor. When I am indoors and some people are sneezing or coughing, I keep my mask on. I draw an analogy between breathing in this kind of air to swimming in Manila Bay. Manila Bay water is teeming with viruses, bacteria, and disgusting stuff. Swimming in its waters probably won’t kill you if you are healthy, but it is pretty gross. It is the same thing with inhaling all that expectorated air enriched with mucus and viral particles without a mask. It probably won’t kill you, but it is pretty disgusting.