Public Health

Why are Covid cases so high when vaccinations are widespread?

Kyndal Bolden, 15, holds her aunt’s hand as she receives a dose of COVID-19 vaccine on August 14, 2021 in New Orleans, Louisiana.

Mario Tama | Getty Images

LONDON – If you look at the Covid case data in the US, UK and the rest of Europe, you might think that despite 18 months of global health crisis and advanced vaccination measures, we are in as bad a situation as we have ever been.

Certainly, the number of daily registered Covid cases in the West remains high and even resembles previous highs at various points or Covid waves during the pandemic.

The current 7-day moving average of daily new cases is 153,246, an increase of 4.9% compared to the previous 7-day moving average (of 146,087). According to the Centers for Disease Control and Prevention (CDC), the current 7-day moving average is 123.6% higher than the value observed about a year ago. In total, more than 40 million Covid cases have been counted in the USA since the beginning of the pandemic.

The number of cases also remains high in Great Britain. On September 6, the seven-day average of new cases per day was nearly 39,000 and the number of cases per day has remained high over the week; Almost 40,000 new cases were reported on Wednesday and around 38,000 cases were recorded on Thursday, government data showed.

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

The high case numbers remain due to the spread of the highly infectious Delta variant, which usurped earlier variants that were themselves more contagious than the original strain of Covid-19.

Nonetheless, the surge in cases has accompanied the advancement of vaccination programs in the West, with the majority of adults in both the US and Europe now fully vaccinated.

In the US, 62.4% of people over the age of 12 are fully vaccinated, CDC data shows, while over 82% of those over 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, ECDC data shows.

Crucially, the hospital admissions and deaths associated with the high case numbers have remained lower (and much lower for some countries) than at earlier stages of the pandemic, when vaccination rates were much lower, proving that those in the west used coronavirus vaccines to drastically reduce the chances of serious infection, hospitalization, and death. US hospital stays remain high, data from Our World in Data shows.

However, none of the vaccines used in the US or Europe are 100% effective, which means that some people who are vaccinated will get Covid (so-called “breakthrough cases”) and a small part of it will get sick. The prevalent Delta variant has also decreased the effectiveness of the vaccines on offer, and some new studies show that immunity from vaccinations decreases over time.

Why are the falls high?

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

“The Delta variant is highly contagious and this explains the persistence of the high number of cases as we now mix much more freely as most of the restrictions have been relaxed,” said Andrew Freedman, an infectious disease reader at Cardiff University School of Medicine CNBC on Thursday.

“Those who are now infected with Covid are a mix of unvaccinated, part-vaccinated and double-vaccinated people. Most of the new infections are in (unvaccinated) children and adolescents, ”he stated.

“We know that the vaccines are only partially effective in preventing people from becoming infected with the Delta variant, but much more effective in protecting against serious illness, hospitalization and death. Fully vaccinated people tend to have mild symptoms when they get them. “A small minority, especially older and more frail people, are still more severely ill.”

In the UK, the latest data from the ZOE Covid Study, which tracks Covid symptoms and infections in the community using data from around a million people each week, suggests that there are currently 17,674 new daily symptomatic cases in the fully vaccinated population in Great Britain there is the United Kingdom

In its latest study, published Thursday, it found that “cases in this group have steadily increased but have now stabilized, with the number reaching 17,342 for the last week.”

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

Similar data covers the US and the rest of Europe last month: CDC data shows that most cases were counted in adolescents ages 16-17 (although ages 12-49 all saw large increases in cases to have ). In the EU / EEA, the highest number of cases is among 25 to 49 year olds, closely followed by 15 to 24 year olds and an increasing number of cases in children aged 5 to 14 years.

Epidemiologists and public health experts have long believed that Covid-19 is just something we need to get used to, that the virus is becoming endemic and cannot now be eradicated.

Pursuing a so-called “zero covid” strategy (with the aim of eliminating all covid cases) has been viewed as hopeless by most countries, although Australia and New Zealand have followed such a strategy. However, Australia announced in late August that it would abandon such a policy in light of the spread of the highly contagious Delta variant. New Zealand is sticking to its strategy for the time being.

Danny Altmann, a professor of immunology at Imperial College London, told CNBC that societies need to judge how well they tolerate the virus.

“We have always said and still claim that the vaccines are amazing and deliver tremendous amounts of protective neutralizing antibodies,” he told CNBC on Thursday. While clinical studies show that the Delta variant reduces the effectiveness of vaccines, Altmann notes, “There is so much leeway for protection that ‘most’ people should be safe.”

“In a way, we saw it that way – with the Delta variant and without vaccination, we would now be at several thousand deaths a day, but we are at ‘only’ a few hundred, so there is a noticeable mitigation of serious illness” , he said.

“However, our protection against Delta seems to be less robust than we predicted, considering that there are around 40,000 cases per day in the UK, including many of these breakthroughs … [and] People who feel significantly unwell despite not being hospitalized, “he said, noting that data from Israel on booster injections showed that additional vaccinations could restore antibody levels and fight groundbreaking cases.

Much of the current debate about Covid, said Altmann, “comes back to this political / philosophical debate about what we want to achieve now”.

“The extremes of the argument are either that, at least until we see what happens in fall / winter, we will have achieved our goal, as the relatively high rollout of vaccines has meant that hospitals are almost dealing with it … or the other view “is that we will not have normality unless we strive for a zero covid strategy that would have to include vaccinations in our schools to stop the spread there,” he noted.

The demands for a zero Covid strategy included people who believed that “we will stay forever for more and more cases until we let a much more resilient variant through to really destroy us,” said Altmann.

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