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Six Rules That Will Define Our Second Pandemic Winter

UnknownKatherine Wu, Ed Yong, and Sarah Zhang write in The Atlantic  that the “pandemic’s endgame has shifted” and we are going to have to adjust our expectations.

While vaccines have largely succeeded in preventing severe infections, they are not protecting against all symptomatic infections or eliminating transmission in the US. One simple reason may be that respiratory diseases are difficult to immunize against. Injections in the arm “are just not very good at stimulating immunity in the nose,” where the virus first takes hold. They are good at stimulating immunity deep in the lungs, thus explaining their prevention of severe disease. Thus the most likely scenario is that, especially with the highly transmissible Delta variant and the likely emergence of further variants, the virus will continue to circulate. 

Even though prevention of severe disease is the most robust and enduring effect of vaccination, “rare events are common at scale” and additional layers of prevention — improved air circulation in buildings mask wearing, and social distancing — will continue to be necessary, especially to prevent infections of the unvaccinated such as children.

The proportion of vaccinated matters but so does their distribution. Fewer of the most vulnerable Americans are vaccinated and they tend to cluster together, creating hotspots — with overwhelmed hospitals running out of ICU beds or beds in general, lacking oxygen, and turning people away — even though the vaccination rate is increasing. While in the UK less than 2% of people over 65 are unvaccinated, in the US the number is above 10% in many counties in the South and Mountain states. The more unvaccinated people are concentrated, the more easily the virus can find its next victim. The demographics of vaccination are also shifting the vulnerable people by age group, down to uninoculated children. Even though children are more resilient against infections compared with adults, the Delta variant means they are at relatively greater risk than before. Relative risk keeps shifting, even if the virus stops mutating and becomes a static risk (which is unlikely). 

And as vaccination increases, a higher proportion of cases will appear in the vaccinated, by the math. So panic over the proportion of vaccinated people in a disease outbreak is misguided, and not an indication that vaccination is not useful. 

‘In July, an NBC News article stated that “At Least 125,000 Fully Vaccinated Americans Have Tested Positive” for the coronavirus. In isolation, that’s an alarming number. But it represented just 0.08 percent of the 165 million people who were fully vaccinated at the time. More recently, Duke University reported that 349 students had tested positive in a single week—a figure that represents just 2.5 percent of the more than 14,000 students who were tested. The denominator matters…’

A longer-lived pandemic will make rare events more noticeable, e.g. “long Covid”, reinfection after recovery, atypical symptoms and affected organs. More people will know someone with such effects. And the virus will continue to mutate. In a more immunized population, a stealthy variant of the virus could succeed the super-transmissible and fast-acting Delta variant or its ilk. What is likely is that the virus will not become deadlier. “Viruses want to spread, not kill.” But, no matter the characteristics of a variant, it cannot persist without lax human behaviors. 

 

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