The Delta Dilemma: Loosening Covid-19 Controls At A Time Of Increased Danger

At a time when the United States and many other countries are beginning to lift restrictions, a new, more dangerous variant of SARS-CoV-2 has appeared that has prompted serious rethinking around what containment strategies should look like moving forward. The Delta variant is not only far more transmissible than its predecessors, but it appears to be more lethal to people of all ages as well. And it doesn’t look like vaccines will be the barrier that stops it.

When the Delta variant surged across India in March and April 2021, fomenting the conditions that pushed the country’s Covid-19 death toll past 400,000 (now estimated to be two million), we knew little about how it compared to preceding strains—only that where it went, havoc followed. Today, the Delta variant has spread to more than 100 countries and become the dominant strain in most, including, as of last week, the United States. Not only is the risk of death from Delta twice as high, it is so transmissible that outbreaks in Australia have been traced back to moments of “scarily fleeting” contact. These characteristics don’t just demand caution, but a reevaluation of current public health policy.

What we have going for us are the mRNA vaccines. Against Delta’s predecessors they perform almost immaculately, with a two-dose regimen preventing nearly all infection, disease, and death in those who received it. But the Delta variant, according to data from Israel (where 80 percent of adults are fully vaccinated), has proven a more challenging immunization target. While the Pfizer vaccine protected 93 percent of immunized Israelis from hospitalization and death, nearly 40 percent were still vulnerable to infection. The British government reported that for symptomatic infection, that rate was about 12 percent. And a recently published study, conducted through May and June in Guangzhou, China, begins to illustrate why.

Read full article on Forbes

Originally published on Forbes (July 13, 2021)

© William A. Haseltine, PhD. All Rights Reserved.