By Monica Gandhi
Despite the team having a 99% vaccination rate, according to school officials, Cal football will not take the field this weekend against USC after at least 44 students and staff tested positive for COVID-19.
Although we do not know all the details of symptoms nor vaccinations of the team, the cancellation of a highly anticipated game like this one due to COVID-19 has led to online speculation — fueled by scary headlines — about the dwindling efficacy of vaccination and a return to the conditions that led to last year’s deadly winter surge.
But, in truth, clusters of mostly asymptomatic cases among the vaccinated, like what we’re seeing at Cal, are neither cause for concern, nor unexpected with a virus that will become endemic. They are an emerging part of our new normal. And we need to start recognizing — and more importantly — speaking about them as such.
Vaccines changed the game and have proven themselves to be highly effective in preventing serious illness and death from COVID-19. Because of that, what we need now is a shift in the way those in the media and in prominent public health positions think about asymptomatic or mildly symptomatic cases.
Prior to the availability of the vaccines, we employed a variety of techniques to control the virus: masks, distancing, ventilation, mass asymptomatic testing (because individuals could spread the virus when asymptomatic). But things have changed. In areas of high vaccination, mass asymptomatic testing no longer needs to done for those who are vaccinated, according to Centers for Disease Control and Prevention guidelines. Even testing for coronavirus exposure should be confined to individuals who were in close contact of a symptomatic person.
Vaccines reduce transmission. Those who are vaccinated are less likely to get infected in the first place, and, if they do, are less likely to spread the disease. A study of symptomatic delta variant breakthroughs from Singapore showed that the viral load by a value on the PCR test (cycle threshold, a test that should not be used to make clinical decisions) may start as high, but quickly comes down in the vaccinated (compared to the unvaccinated). This makes sense, since the immune response in the vaccinated can take a moment to kick in and fight the virus. Moreover, another study shows that delta symptomatic breakthroughs among health care workers in the Netherlands had a lower ability to be cultured, which means the virus is less likely to be infectious and spread to others. Data from careful contact tracing studies in Singapore, England, Canada and various summer camps also show that asymptomatic vaccinated people are unlikely to transmit to other vaccinated individuals.
It’s essential to remember that we only need to take emergency medical or public health measures if there are clinical implications in play. An asymptomatic vaccinated person is not clinically unwell and vaccines reduce symptoms if a breakthrough does occur. Moreover, if vaccines reduce the chance of being infected (vaccinated people are 13 times less likely to be infected than unvaccinated) an asymptomatic vaccinated person should not be tested without a direct exposure from someone who is ill.
Finally, asymptomatic positive tests add to case counts. This has consequences for our daily lives, since public health officials in the Bay Area (except for Marin County) appear to be using this metric to determine the necessity of restrictions such as masks, instead of a more appropriate index like COVID hospitalizations and vaccination rates.
Young people have been restricted during the pandemic in the United States — despite being less at risk for severe illness — in order to protect others. We owe it to them to return their lives to normal, especially when that was the promise of public health officials in the context of vaccine mandates at many colleges and universities. Football (an outside activity) was shown to be safe and lead to no transmissions in a study from last year, prior to vaccinations and in areas of high community transmission. It is too late for this Cal-USC football game, but we need to think of outbreaks differently from now on in the context of the vaccines and live our lives accordingly.
Monica Gandhi is an infectious diseases specialist and professor of medicine at UCSF.