Why are Covid cases so high when vaccination is widespread?

LONDON – Looking at the data from the Covid case in the US, the UK and the rest of Europe, you would be forgiven for thinking that, despite the 18 months of global health crisis and the advanced advances in vaccination, we are in such a bad situation . as we always were.

Certainly, the number of Covid cases recorded daily in the West remains high, and even resembles previous peaks at different points, or Covid waves, during the pandemic.

The current moving average of new 7-day daily cases stands at 153,246, an increase of 4.9% compared to the previous 7-day moving average (of 146,087). The current 7-day moving average is 123.6% higher than the value observed about a year ago, according to data collected by the Centers for Disease Control and Prevention (CDC). In all, more than 40 million cases of Covid have been counted in the U.S. since the pandemic began.

Case rates in the UK also remain high. As of September 6, the seven-day average of new daily cases was nearly 39,000 and the number of daily cases has remained high as the week has progressed; nearly 40,000 new cases were registered on Wednesday and about 38,000 cases were registered on Thursday, according to government data.

In the EU + EEA area (a total of 30 countries), in the seven days to September 5, 405,774 new cases were registered, according to the European Center for Disease Prevention and Control, with Ireland, France, Sweden, Portugal , Greece and Bulgaria are the countries with the highest number of new cases per 100,000 inhabitants.

The high number of cases is still attributable to the spread of the highly infectious delta variant, which usurped earlier variants that were more infectious than the original Covid-19 strain.

However, the increase in cases has accompanied the advancement of vaccination programs in the West, as most adults in the United States and Europe are already fully vaccinated.

In the United States, 62.4% of all people over the age of 12 are fully vaccinated, according to CDC data, while more than 82% of those over the age of 65 are fully protected. In the UK, 80.4% of the population over the age of 16 are fully vaccinated and in the EU / EEA, 70.4% of adults have received two doses of a coronavirus vaccine, according to ECDC data .

Crucially, the number of hospitalizations and deaths that accompany the high number of cases has remained lower (and in some countries, much lower) than in the previous points of the pandemic, when vaccination rates were much lower, proving that coronavirus vaccines used in the West drastically reduce the chance of serious infection, hospitalization, and death. Hospitalizations in the United States remain high, according to data from Our World in Data.

However, none of the vaccines used in the US or Europe are 100% effective, meaning that some vaccinated people will get Covid (the so-called “advanced cases”) and a small number of them will get sick. . The predominant delta variant has also reduced the effectiveness of the vaccines offered and some new studies show that the immunity provided by shots decreases over time.

CNBC asked UK-based epidemiologists why cases remain so high given relatively high vaccination rates in the West.

“The delta variant is highly contagious and that explains the continuing high number of cases now that we are mixing with much more freedom, as most of the restrictions were reduced,” Andrew Freedman, a reader of infectious diseases, told CNBC on Thursday. Cardiff University. .

“Those who catch Covid are now a mix of unvaccinated, partially vaccinated and double-vaccinated people. A large proportion of the new infection occurs in children and adolescents (unvaccinated),” he noted.

“We know that vaccines are only partially effective in preventing people from catching the delta variant, but they are much more effective in protecting against serious illness, hospitalization and death. A small minority, especially the elderly and more frail, continue to suffer more illnesses. serious “.

In the UK, the latest data from the ZOE Covid study, which tracks Covid symptoms and infections in the community using data from one million people each week, estimates that there are currently 17,674 in the fully vaccinated population. daily symptomatic cases in the UK

He noted, in his latest investigation published on Thursday, that “cases in this group had steadily increased, but have now stabilized, with last week’s figure of 17,342.”

Meanwhile, new cases of Covid are the highest among 0-18 and 18-35 year olds, many of whom are only partially vaccinated (two doses of a Covid shot are vital for maximum protection) or unvaccinated.

Similar data is from the United States and the rest of Europe over the past month: CDC data show that the highest number of cases has been among adolescents aged 16 to 17 (although age groups from 12 to 49 years have seen a sharp increase in cases). In the EU / EEA, the highest number of cases is between the ages of 25 and 49, followed closely by those aged 15 to 24 and an increasing number of cases among children aged 5 to 14.

Epidemiologists and public health experts have long expressed the view that Covid-19 is something we will have to get used to, that the virus will become endemic and will now not be eradicated.

Following a strategy called “zero Covid” (with the aim of eliminating all Covid cases) has been seen as a desperate cause by most countries, although Australia and New Zealand have followed this strategy. However, Australia announced in late August that it was abandoning this policy, given the spread of the highly infectious delta variant. New Zealand maintains its strategy, for now.

Danny Altmann, a professor of immunology at Imperial College London, told CNBC that societies need to assess the extent to which they will tolerate the virus.

“We’ve always said and maintained that vaccines are amazing and offer huge levels of protective neutralizing antibodies,” he told CNBC on Thursday. Even though clinical studies show that the delta variant reduces the effectiveness of vaccines, Altmann noted that “there is so much protective margin that most people should be safe.”

“In a sense, this is how we have seen it develop: with the delta variant and no vaccination, we would now be in several thousand deaths a day, but we are in ‘only’ a few hundred, so there is tangible mitigation. of serious illness, “he said.

“However, our protection seems less robust against the delta than we had predicted when we consider that in the UK there are around 40,000 cases a day, including many of these advances … [and] people are significantly ill even though they are not hospitalized, ”he said, noting that Israel’s data on conducting reinforcements showed that additional blows could increase antibody levels and combat advanced cases.

Much of the debate around Covid today, Altmann said, “returns to this policy / philosophy debate about what we are now trying to achieve.”

“The extremes of the argument are that, at least until we see what happens in the fall / winter, we have achieved our goal, as the relatively high vaccine deployment has made it possible for hospitals to do so almost .. Or, the other view is that we will never have normalcy if we do not strive to achieve a zero-coveted strategy, which should include vaccination in our schools to stop spreading, ”he said.

Those calling for a zero-covida strategy encompassed people who believed that “we are sitting in perpetuity for ever more cases, until we allow a much more resilient variant to escape us,” Altmann said.