A recent increase in the number of reported cases of COVID-19 is recorded especially in Europe and the Americas.  In response to the discussion about the concept of reaching so-called “herd immunity” by letting the virus spread, WHO Director General said that herd immunity has not been used as a strategy for responding to an outbreak, let alone a pandemic. Herd immunity is a concept used for vaccination, in which a population can be protected from a certain virus if a threshold of vaccination is reached. WHO acknowledges the general frustration and is hopeful that countries will use targeted interventions based on the local situation. The answer is a comprehensive approach rather than a choice between letting the virus run free and shutting down our societies.

Remarks by Dr Tedros Adhanom Ghebreyesus
Around the world, we’re now seeing an increase in the number of reported cases of COVID-19, especially in Europe and the Americas. Each of the last four days has been the highest number of cases reported so far. Many cities and countries are also reporting an increase in hospitalizations and intensive care bed occupancy. At the same time, we must remember that this is an uneven pandemic. Countries have responded differently, and countries have been affected differently. Almost 70% of all cases reported globally last week were from 10 countries, and almost half of all cases were from just three countries. For every country that is experiencing an increase, there are many others that have successfully prevented or controlled widespread transmission with proven measures. Those measures continue to be our best defence against COVID-19. There has been some discussion recently about the concept of reaching so-called “herd immunity” by letting the virus spread. Herd immunity is a concept used for vaccination, in which a population can be protected from a certain virus if a threshold of vaccination is reached. For example, herd immunity against measles requires about 95% of a population to be vaccinated. The remaining 5% will be protected by the fact that measles will not spread among those who are vaccinated. For polio, the threshold is about 80%. In other words, herd immunity is achieved by protecting people from a virus, not by exposing them to it. Never in the history of public health has herd immunity been used as a strategy for responding to an outbreak, let alone a pandemic. It is scientifically and ethically problematic.
First, we don’t know enough about immunity to COVID-19. Most people who are infected with the virus that causes COVID-19 develop an immune response within the first few weeks, but we don’t know how strong or lasting that immune response is, or how it differs for different people. We have some clues, but we don’t have the complete picture.There have also been some examples of people infected with COVID-19 being infected for a second time.
Second, the vast majority of people in most countries remain susceptible to this virus. Seroprevalence surveys suggest that in most countries, less than 10% of the population have been infected with the COVID-19 virus. Letting the virus circulate unchecked therefore means allowing unnecessary infections, suffering and death. And although older people and those with underlying conditions are most at risk of severe disease and death, they are not the only ones at risk. People of all ages have died.
Third, we’re only beginning to understand the long-term health impacts among people with COVID-19. I have met with patient groups suffering with what is now being described as “Long COVID” to understand their suffering and needs so we can advance research and rehabilitation. Allowing a dangerous virus that we don’t fully understand to run free is simply unethical. It’s not an option. But we do have many options. There are many things that countries can do and are doing to control transmission and save lives. It’s not a choice between letting the virus run free and shutting down our societies.
This virus transmits mainly between close contacts and causes outbreaks that can be controlled by implementing targeted measures. Prevent amplifying events. Protect the vulnerable. Empower, educate and engage communities. And persist with the same tools that we have been advocating since day one: find, isolate, test and care for cases, and trace and quarantine their contacts.
This is what countries are proving works, every day. Digital technologies are helping to make these tried-and-tested public health tools even more effective, such as mobile applications to support contact tracing efforts. Germany’s Corona-Warn app has been used to transmit 1.2 million test results from labs to users in its first 100 days. The Aarogya Setu app from India has been downloaded by 150 million users, and has helped city public health departments to identify areas where clusters could be anticipated and expand testing in a targeted way. In Denmark, more than 2700 people have been tested for COVID-19 as a result of notifications received through a mobile application. And the United Kingdom has rolled out a new version of its NHS COVID-19 app, which had more than 10 million downloads within the first week. As well as alerting users that they may have been exposed to a positive COVID-19 case, the app allows users to book a test and receive results, keep track of the places they’ve visited and receive the latest advice on local restrictions. WHO is working with the European Centre for Disease Prevention and Control to help countries evaluate the effectiveness of their digital contact tracing apps. This is just one example of the innovative measures countries are taking to control COVID-19.
There are many tools at our disposal: WHO recommends case finding, isolation, testing, compassionate care, contact tracing, quarantine, physical distancing, hand hygiene, masks, respiratory etiquette, ventilation, avoiding crowds and more.  We recognize that at certain points, some countries have had no choice but to issue stay-at-home orders and other measures, to buy time. Many countries have used that time to develop plans, train health workers, put supplies in place, increase testing capacity, reduce testing time and improve care for patients.
WHO is hopeful that countries will use targeted interventions where and when needed, based on the local situation. We well understand the frustration that many people, communities and governments are feeling as the pandemic drags on, and as cases rise again.
There are no shortcuts, and no silver bullets.
The answer is a comprehensive approach, using every tool in the toolbox.
This is not theory: countries have done it and are doing it today, successfully.
My message to every country now weighing up its options is: you can do it too.
I thank you.
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In late May 2020, President Donald Trump announced the US would cut off its relationship with WHO and redirect funds to US global health priorities. In July 2020, the US administration officially notified UN Secretary-General António Guterres of its intention to withdraw from WHO membership.
Last week, Dielli filed a compilation of updated information on overdispersion as a key factor of the pandemic and the confirmation by the CDC on the airborne transmission of the novel coronavirus.