Covid-19 cases are exponentially rising across the world, including in the United States. New York City, for example, continues to break its own record for positive cases in a single day. Much of the concern with these new infections relates to cases in which a fully vaccinated individual contracts the disease.
As we have seen with other vaccines, breakthrough cases occur. They are expected to occur, and they will continue to occur.
But it’s wrong to read the situation as a sign that the vaccines aren’t working; in fact, how Covid is being experienced in the vaccinated is a sign that they are. The messaging around these infections wrongly focuses on their numbers and uses a misunderstood term — “breakthrough” infections — that can make the cases sound more unexpected and dangerous than they are. Receiving a vaccination doesn’t mean that recipients don’t need to worry about getting any symptoms of a given illness. What vaccinations offer is enhanced safety from severe illness and death.
As we have seen with other vaccines, breakthrough cases occur. They are expected to occur, and they will continue to occur. What is remarkable about the Covid vaccinations is their ability to prevent a great number of serious illnesses, hospitalizations and deaths in the face of breakthrough infections, and to effectively do that for different strains.
The vaccines are working — but we need to be clearer about how we discuss their efficacy and how this should be measured. The unfortunate medical terminology of “breakthrough” cases has resulted in damaging confusion, with many conflating these infections with vaccine failure. Instead, we should focus on the impact of these breakthroughs.
The Centers for Disease Control and Prevention reports that the risk of Covid infection is eight times higher in the unvaccinated than in the vaccinated; the risk of hospitalization or death in the unvaccinated population is 25 times higher. And while there is evidence that omicron is more skillful than delta in outmaneuvering the Covid vaccines, there is also data suggesting that those who are vaccinated are likely to experience milder symptoms, while hospitalizations may be prevented in 70 percent of cases.
In other words, the vaccines that were developed prior to the outbreak of omicron and its "wacko" new mutations, as a former official at the California Department of Public Health put it, are still effectively fighting this novel strain. That itself demonstrates the remarkable power and importance of getting the Covid shots.
Of course, while the vaccines seem to decrease severe illness and death in the vaccinated, our understanding of how effective the shots are at preventing the illness is still evolving— it could be that the number of breakthrough cases indicate further research is needed to optimize vaccine potency.
That’s why, even when people are vaccinated, it’s important to maintain precautions such as wearing masks, getting tested before gatherings and social distancing, while scientists investigate how effectively the vaccines battle the new variant. And it’s particularly important to help protect those, such as young children, the elderly and the immunocompromised, for whom vaccines may not yet be available or be as effective.
Still, what we are seeing with Covid inoculations tracks so far with other vaccines. The mumps vaccine, according to the CDC, is 88 percent effective at preventing infection. Similarly, the chickenpox vaccine has an efficacy of 85 percent. And in 2019, the influenza vaccine was about 45 percent effective.
Importantly, for all three vaccinations, individuals who have breakthrough cases experience significantly reduced symptoms compared to the unvaccinated. For mumps, breakthrough cases result in milder symptoms and a decreased likelihood of developing severe neurological complications such as encephalitis and meningitis. With the chickenpox vaccine, patients develop less severe fevers and skin eruptions than the unvaccinated. And the influenza vaccine, despite reducing the risk of flu by just 40 to 60 percent overall, prevented an estimated 7.5 million cases and 6,300 influenza-associated deaths in the 2019-2020 season alone.
The Biden White House, to its credit, is attempting to shift public discourse surrounding Covid from a focus on the total number of cases of the virus to a reporting of its resulting deaths and hospitalizations. During a press briefing Dec. 20, White House press secretary Jen Psaki caught herself as she began to describe the goal of reducing Covid cases and instead stressed reducing more serious outcomes. She responded to a question by explaining that President Joe Biden’s objective “is to continue to make vaccines available, reduce cases around the co-," then stopped herself and resumed with,“reduce hospitalizations and deaths across the country."
This is an important change from previous benchmarks, which had underscored the importance of limiting the sheer quantity of Covid infections. Focusing on case numbers – especially as the illness moves toward becoming endemic, or regularly found within a population like the common cold and the flu are — is misplaced because it focuses on the wrong number, which seems larger and scarier than the actual threat the virus represents. It doesn’t screen out for the details that matter: whether cases are asymptomatic; whether they result in hospitalizations and deaths; whether they are occurring among fully vaccinated people. Without this further context, it’s impossible to measure the impact of these breakthrough cases.
While it can be frustrating to have received a Covid vaccination and then come down with the illness, it’s a mistake to think that vaccines can free us entirely from illness — or that it was pointless to get the shots in the first place. Breakthrough infections are, in fact, part and parcel of immunization as long as a disease is circulating. If the vaccines are saving lives, they're doing their job.