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On Sunday, Metropole brings you a COVID-19 update from Prof. Dr. Florian Krammer, an Austrian virologist who works and teaches at the Icahn School of Medicine at Mount Sinai, New York City.

September 12, 2021

Here again is our biweekly COVID-19 update.

To date, 225 million official SARS-CoV-2 infections have been recorded, 4,641,000 people have officially died from COVID-19, and 5.69 billion doses of vaccine have been administered. Globally, case numbers and death rates are going down right now.

Complex Europe

Let’s start in Europe. The situation here is very different in different countries.

In Spain, France, Italy, Portugal, etc., the Delta wave is subsiding (and was never really bad in some countries). Elsewhere (Germany, Austria, Ukraine, Switzerland, Slovenia, Croatia, Slovakia) cases are going up. Greece, Serbia, Bulgaria, Norway and Finland are in the middle of a wave. And in Poland, Czechia and Hungary, you don’t notice much of a delta wave yet.

Interesting cases are Great Britain, where the number of cases is rising again, and the Netherlands, where the number of cases has gone down, but has settled at a rather high level. Sweden and Belgium are recording cases, but the numbers are stable and relatively low. In Russia, by the way, case numbers are also going down, but very very slowly.

Two days ago, Denmark (73% vaccination coverage, 96% among those aged 65 or older) declared the pandemic in the country virtually over and lifted the last restrictions. I’m keeping my fingers crossed for them. I can imagine that some countries with high vaccination coverage (more than 70%) will soon follow suit if it works.

Abating Delta Wave in the Americas

In the USA the number of cases is decreasing, it seems that we are over the Delta wave. In New York, the number of cases is also decreasing slightly, but Delta has never been very strong here (which may also have to do with the vaccination coverage and the number of people infected, especially in the first wave – immunity in the population is very high).

In Canada, case numbers are still rising; in Mexico, they are falling again. Some countries in Central America have high numbers of cases but the situation in South America (except Venezuela) is relaxed. Even in Brazil, the number of cases is decreasing.

Strong Delta Wave in Asia, Improvements in Africa

In Asia, the Philippines, Malaysia, Thailand, Pakistan, Vietnam, Azerbaijan, etc. are in the middle of strong Delta waves. In many other Asian countries, however, the situation is either under control or case numbers are declining.

In the Middle East and Maghreb, case numbers are stable or declining almost everywhere, except for Palestine and Egypt. In Israel, the number of infections is also decreasing. Africa looks actually also good with few exceptions where the case numbers are high (Ethiopia, Ghana, Angola, DRC, Rwanda).

So, not so bad on the whole.

Vaccine Update

Now a few vaccination updates. Because last time there were so many questions about vaccination for pregnant women. Large studies have shown that vaccination in pregnancy is safe. In the USA, vaccination is explicitly recommended for pregnant women in all trimesters by the CDC and by professional organizations. The German Stiko also recommended vaccination for pregnant women a few days ago, but only in the 2nd and 3rd trimester – they are more conservative in their recommendations. However, based on the data, I think the US recommendation is correct.

I was going to write more about booster vaccines and vaccines for children under 12 this week. Unfortunately, the data from the “under-12” Pfizer-Biontech study is not in yet. And the FDA meets on September 17 to decide on a third vaccine “booster” shot (which is recommended for immunocompromised people in the US, but not for healthy adults).

I will probably write about that in two weeks (or in between, when the Pfizer-Biontech data comes out and I have time).

Effectiveness Over Time & Delta

What I would like to mention here in more detail is the vaccine effectiveness over time and at Delta. Last week I looked through all available studies and made a list.

As a refresher: We distinguish between vaccine efficacy and vaccine effectiveness.

Vaccine efficacy is measured in controlled phase III trials, vaccine effectiveness comes from observational studies when the vaccine is then used in the population.

Typically, efficiency is higher than effectiveness. Efficacy of most vaccines is related to symptomatic infections (except for J&J, where it is moderate to severe disease, mild disease was not included as an endpoint).

Now there has been a lot of concern, especially from Israel, that the effectiveness is declining. And that is the case, for two reasons.

First, the immune response starts to drop a few weeks after vaccination. That’s normal, and then the immune response settles down to a stable level after a couple of months. But, of course, that can put downward pressure on effectiveness. Secondly, Delta started to circulate, and Delta is more contagious, multiplies better in the upper respiratory tract, and is also a mild “escape mutant” (though not very strong). And those two factors came together and that’s how the efficacy dropped.

Initially, mRNA vaccines had about 90% protection against infection. Now, depending on the study, the efficacy is between 50 and 90% for protection against infections. That includes asymptomatic infections (which were not measured in the Phase III registration trials). The majority of studies see about 75-85% effectiveness, which is actually very good.

However, protection against serious infections is holding up and has not fallen. AstraZeneca, by the way, is also holding up quite well (no data from J&J yet). But, due to the lower effectiveness, infections of vaccinated people occur more often (I know some such cases in my circle of acquaintances, all cases were mild and the illness was short).

While they often do not reproduce the virus, in rare cases chains of infection can occur in vaccinated people.

Based on these studies –and there are quite a few by now – it can be said that the vaccines still work very well and provide excellent protection.

I suspect that the protective effect will probably not decrease further because the immune response is stabilizing.

What About those Who Recovered from the Virus?

A short word to those who recovered from the virus, because there is a lot of debate on this at the moment:

I would recommend vaccination to everyone who has recovered because the antibody response in the blood after vaccination is very high and homogeneous. After an infection, it varies a lot (some people react strongly, some only very weakly). Basically, though, it shows that having been through an infection provides about as much protection against a Delta infection as vaccination.

So, I think a “2G” rule makes more sense than a “1G” rule. The protection that recovered people have is apparently often ignored. By the way, if you were infected and then get vaccinated once, you build up something like a super immunity, which is a lot stronger than the immunity after an infection or after a vaccination.

I will report in two weeks (or maybe before if there is something interesting new about vaccination for children).

Best regards!

PS: I am humbled to to put this here, but I was nominated in the category scientist as Austrian of the Year. I would be happy if you wanted to vote for me.

Prof. Dr. Florian Krammer
Prof. Krammer is the Principal Investigator of the Sinai-Emory Multi-Institutional Collaborative Influenza Vaccine Innovation Center (SEM-CIVIC). Currently Prof. Krammer holds a position as a Professor of Vaccinology at the Department of Microbiology at the Icahn School of Medicine at Mount Sinai. He has published more than 100 papers, is member of the editorial boards of the Journal of Virology, Plos One and Heliyon and is a peer reviewer for more than 30 journals.

Current Status

If you live in Vienna, make sure to register for getting a vaccine against COVID-19 under  Here you can book your vaccination appointment.

The City of Vienna offers free vaccinations without an appointment to everyone – regardless of citizenship or insurance status – at multiple locations across the city. 

Vienna has reinstated a number of coronavirus restrictions for the fall. The Austrian government has presented a plan for schools and universities.  

Here’s an overview of where you can get tested for COVID-19 in Vienna and how the free PCR “gargle” tests at home work. 

If everything is a bit much for you or you experience domestic violence of any kind, here is our mental health resource article.


For current coronavirus numbers, check the website of Ministry of Health and the AGES dashboard.

The Austrian Ministry of Health also publishes daily vaccination statistics and a preview of scheduled deliveries.


The City of Vienna has compiled comprehensive information on questions and answers regarding coronavirus and the COVID-19 disease in English.

The Austrian Ministry of Health has put together FAQs on the coronavirus and also provides material to download on how to protect yourself and others from the disease, also in English.

Furthermore, the ministry will constantly update its German-language website with information on the number of people tested and cases of COVID-19 in Austria.


Health advice by telephone1450

If you show symptoms (fever, cough, shortness of breath, breathing difficulties) or fear that you are ill, stay at home and dial health number 1450 for further procedures (diagnostic clarification).

Coronavirus hotline AGES+43 0800 555 621

The Austrian Agency for Health and Food Safety (AGES) answers questions about the coronavirus (general information on transmission, symptoms, prevention) 24 hours a day at +43 0800 555 621.

VKI hotline for travel law questions+43 0800 201 211

For legal questions concerning trips that have already been booked (e.g. whether a trip can be cancelled free of charge), the experts of the Association for Consumer Information (VKI) provide advice free of charge from Monday to Sunday between 09:00 and 15:00 at +43 0800 201 211.