As Covid-19 cases rise in the United States and the Delta variant rises in prevalence, trends from Israel and the United Kingdom – where the variant became dominant a few weeks earlier than in the US – present hope for a less deadly and severe surge than others that have come before.
And while there is some evidence that the Delta variant may evade some natural immunity from prior infection and reduce the efficacy of the vaccines, experts say that vaccination progress will be the most critical factor in preventing the worst outcomes.
In Israel, average daily cases are twice what they were in mid-April, when the first cases of Delta were identified in the country. At that time, there were an average of five deaths each day in Israel. But despite the rise of the Delta variant – which now accounts for more than 90% of new cases in the country – average daily deaths have stayed consistently below that. In fact, Israel has had an average of less than two Covid-19 deaths per day since the last week of May, according to data from Johns Hopkins University.
In the United Kingdom, both cases and deaths are higher than they were when the Delta variant became the dominant strain in the country in mid-May, but cases have climbed exponentially faster than deaths. Average daily deaths in the UK are about twice what they were when the Delta variant became dominant, and cases are about 12 times what they were. Even three weeks ago, cases had climbed to nearly four times what they were when the variant became dominant.
When the first cases of the Delta variant were identified in Israel, about 56% of the population was already fully vaccinated, according to Our World in Data. But in the UK, only 2% of the population was fully vaccinated when the Delta variant was first identified there, only reaching 50% vaccination within the past week.
Overall, vaccination rates in the US fall somewhere between Israel and the UK. About 16% of the population was fully vaccinated when the first cases of Delta were identified in the US and about 48% are fully vaccinated now that the variant has become dominant.
“In my mind, vaccines are the single most important factor” in the fight against the Delta variant, Becky Dutch, a virologist and chair of the University of Kentucky’s department of molecular and cellular biochemistry, told CNN.
“The US is a patchwork now,” she said. “It depends on where you live. If you live in a place with high vaccination rates and you’re vaccinated yourself, I’m not overly concerned about you. But if you’re sitting in an area of the country with 35% of the population vaccinated and you’re not vaccinated, I’m much more concerned.”