No, the BAU/ml antibody unit is not a “fabrication” by large pharmaceutical companies

A Facebook post containing several claims with false information on health issues has been spreading widely on the social network. The post is from the personal profile of Dr. Georgi Todorov – a laboratory doctor from Ruse, who became known for his sharp criticism of the protective measures and vaccines against COVID-19.

From November 10th to November 22nd, Dr. Todorov’s post gathered more than 1400 reactions, more than 100 comments, and was shared nearly 800 times. The content of the post was copied and posted by Dimitar Georgiev on November 14 and this publication became even more popular on the social network. So far, Georgiev’s post has garnered more than 6800 reactions, nearly 160 comments and has been shared more than 7100 times.

“After they invent new medicine, introducing the term asymptomatic patients, then new mathematics, which claims that in a city with a population of 5000 people, we can have 1000 people sick out of 100 000! It was about time for them to create a new laboratory measure unit for antibodies against SARS-CoV-2. Antibodies are immunoglobulins of type D and are measured in G/liter or milligram/millilitre, the current proposed unit of measurement BAU/ml is a fabrication in medical science and metrics, it means binding unsaturated antibodies/ml and was introduced by major pharmaceutical manufacturers – Roche, Abbott, Diasorin, etc. We have new metrics now! Psychopaths are always resourceful when achieving their goals! I am a laboratory doctor, after all, therefore I understand measure units at least! Thanks to the Ministry of Health for their contribution to metrics and immunology.”

This is what Dr. Todorov wrote in the first part of his post. The original spelling of the post is preserved in the text above. In this part of the post Factcheck.bg found two statements that do not correspond to the truth. Here is what our inspection showed:

Standardized indicator

Measuring mortality and morbidity per 100 000 population is a standardized indicator, not “new mathematics.” It ensures the comparability of statistical information in time and space. If we look for the indicator for the whole country, for example, it is obtained by dividing the registered infections or deaths by the total population, and the result is multiplied by 100 000 (accepted standard population size). Multiplying by 100,000 does not change the values, but allows the levels to be compared over time, between districts, countries, etc.

The calculation does not apply to cities, but to districts in the country, in order to monitor the epidemic situation. Up-to-date statistics for the situation in Bulgaria can be seen on the website of the National Center of Infectious and Parasitic Diseases. There, it is also explained how the data is calculated for different indicators. For example, the analysis of the 14-day morbidity rate by district is done every Sunday. “For the respective day, the number of newly registered laboratory-confirmed cases during the current and previous 13 days is summed up, the amount is divided among the population in the respective district and multiplied by 100,000… The data provides an instant comparative picture by district.”

The National Pandemic Plan for SARS-CoV-2 of July 2021 states that the comparative picture assesses the epidemic situation and plans anti-epidemic measures – calculates the provision of the population with hospital beds, what should be the outpatient medical care for doctors and others.

Can there be 1,000 people sick per 100,000 in a city of 5,000?

Although the data is calculated for districts and not for cities, simple calculation answers this question. Hypothetically, if there are 50 registered infections in a city with a population of 5000, the ratio of 1000 people infected per 100 000 population will be met. So the answer to the question is yes.

The Unit of Measure BAU/ml 

In Bulgaria, obtaining a COVID certificate for having antibodies against coronavirus became possible after the Minister of Health’s order from November 11, 2021. According to it, citizens can now receive a COVID certificate and a “certificate of antibodies against SARS-CoV-2, proven by a laboratory test for quantitative testing of Anti-SARS-CoV2 IgG with values ​​greater than 150 BAU/ml”. Certificates are valid for 90 days from the date of the laboratory test.

The BAU/ml unit (Binding Antibody Units) was adopted by the WHO Expert Committee on Biological Standardization (ECBS) in December 2020, and not by the “big pharma producers”, as Dr. Todorov claims. The unit is not a “contribution to metrics and immunology” by the Ministry of Health. The unit is part of the International Standard, according to which the results of tests for the detection of specific antibodies to SARS-CoV-2 are updated to BAU/ml. For more explanations Factcheck.bg contacted Prof. Radka Argirova – President of the Bulgarian Society of Medical Virology, a member of the Expert Council of Virology under the Ministry of Health and a member of the National Expert Board of Virology under the Bulgarian Medical Association.

Professor Argirova explained that BAU/ml is an internationally accepted unit that is really “made up”. However, it aims to unify and make comparable all existing antibody units. According to the COVID-19 Diagnostic Testing Database of the Joint Research Center of the European Commission, as of November 3, 2021, there are 595 different tests for the detection of antibodies against SARS-CoV-2. As of the same date, 469 different tests were used in the EU.

“Since every company that produces antibody tests and markets them is practically running away from a patent – they are doing new tests and creating, introducing new units, these units need to be standardized. Because the units are designed to be different, they also have different thresholds above which antibodies are present and below which they are not. As the threshold values ​​of the units are very different, there is no comparability between them. That’s why the WHO invented the BAU unit per millilitre – it equalize the various thresholds under a common denominator, the same concept we know from school. The WHO has also defined a common standard that is used to set the threshold units to a single BAU figure on each test. Thus, a comparison can now be made between the different units of the different tests – those with a threshold of 5 units and those with a threshold of 25 units. If one clings to the statement that this is a fictional unit – yes, it really is fictional. But it was introduced with a clear purpose that needs to be explained and understood.”

The fourth wave of Covid-19 misinformation is here

In the second part of his publication, Dr. Todorov’s writes the following:

“And why the antibodies found are valid for only 3 months can answer the Ministry of Health, but they assured me that it was at the request of Murdzheva, given by me to a prosecutor, and Iva Hristova who never saw a sick patient and who lives in the TV! Let’s not forget that once the antibodies are detected, it means that your entire immune system is in order, but the Ministry of Health has an order to vaccinate you, not to take care of you.”

The original spelling of the Facebook post is again kept in the text above.

Why are antibodies certificates valid for only 3 months?

Dr. Todorov disputes the validity of the antibody certificates, arguing that once a person has developed antibodies, his immune system is already in order. This statement is not supported by existing scientific data. People who have suffered from COVID-19 do not develop lifelong immunity against the virus, reported Factcheck.bg in its inspection in June. There is still no clear answer to the question how long immunity against the virus lasts after illness. Scientists agree that for each person this period is strictly individual, different, due to, for example, one‘s immune system, the subsequent encounter with the virus and others. However, the protection naturally decreases after a certain period of time.

“Experience has shown that after about 3 months, antibodies begin to decline. This does not surprise us, because antibodies have dynamics of formation, peak and decline. However, the immune system is strictly individual for each person – in some the antibodies may begin to decline after the second month, in others – after the sixth month. It also depends on whether people encounter the virus again. That‘s why we decided to take an average of 3 months, similarly to Austria and Switzerland (ed. note – where antibody certificates are also issued). Initially, there was a proposal to measure antibodies every month, but we did not agree with that, because it would be too costly for the people, “said Prof. Argirova.

This Healthline review from October 22 discusses some of the latest research projects on the subject. Every research is accompanied by a link, and all the facts in the article are verified. The article also cites a study that found that immunity against the virus lasts up to 8 months. The same study is referred to by the Ministry of Health in its Reasons for the Order, which introduces the antibodies certificate as a way to obtain a green certificate. Other research projects in the Motives of the Ministry of Health can be seen here, here and here. The motives are compiled on the basis of the opinions of the Expert Council of Virology under the Ministry of Health (here), the Expert Council of Clinical Immunology (here) and the Expert Council of Clinical Laboratory (here).

Prof. Argirova commented on the 90-day validity of the antibodies certificates and the connection with the quantities of antibodies themselves. According to her, the norm for the presence of antibodies is 15 BAU/ml – this indicates that a person has antibodies and has suffered from the virus. “However, the goal of the Ministry was not to prove that a person simply got sick, but that he was protected by his antibodies as a result of getting sick. That is why all three Expert Councils under the Ministry of Health united and referred to several scientific articles that show that at 10 times above this value of 15 BAU/ml we do not just have antibodies, but lasting protection – among antibodies there is a sufficient number of neutralizing antibodies.

The expert explained that there are many types of antibodies, but in this case, only the neutralizing ones are important because only they protect from the virus. For example, a result in the first one-third of the range of 15 to 150 BAU/ml indicates that a person has antibodies, but they do not prevent further infection because the number of neutralizing ones is very small. The second third of the scale shows that there are more neutralizing antibodies, but again not enough to prevent from another infection. The third third shows that the neutralizing antibodies are sufficient and can prevent infection. In this case, a value of at least 150 BAU/ml is set, so that within 3 months after the test there will be a guarantee that the neutralizing antibodies will not fall below the threatening threshold.

“A question arises – why not get tested for neutralizing antibodies only. The answer is very simple – we had this idea in mind, but it turned out that very few laboratories in the country have purchased such tests and work with them. Because people are in a hurry and want to get their certificates, we decided to use only BAU/ml for now, and maybe in the future, in the upcoming months, we will consider introducing a test only for neutralizing antibodies,” added Prof. Argirova.

Lifetime immunity against COVID-19?

About Dr. Georgi Todorov

Dr. Georgi Todorov was a candidate from the There Is Such A People party in this year’s elections for the 46th National Assembly in July – fourth place in the party list in 8th Multi-member Constituency – Dobrich. This was also confirmed by party members from Ruse and Dobrich. Svetlin Stoyanov from Ruse and Krassimir Milkov from Dobrich failed to answer the question of whether Todorov is a member of the party. “I can’t comment, I haven’t talked to him or seen him. I can’t say 100% whether he is a member”, pointed out Milkov. However, the doctor is an extremely active participant in the programs on TV 7/8.

About Dimitar Georgiev

Dimitar Georgiev (mentioned above as a “super distributor” of Todorov’s post) is a member of the Vazrazhdane (Revival) party. In a pre-election material for a local media, he states that he has been part of the party since August 21, 2020. Georgiev was a candidate in the elections in April, July and November 2021, occupying the 2nd position in Vazrazdane’s lists in Vratsa region. Georgiev is also a member of the Organizing Council of Vazrazhdane and the chairman of Vazrazhdane-Kozloduy.

In connection with the numerous political statements circulating in the society related to vaccines, Prof. Argirova insisted that we quote the following words in this text: “Something that has to do with the disease cannot be taken as a political platform, especially when we are in a pandemic situation. Anti-vaccination cannot be a platform for entering parliament. What facts do they rely on? Everyone has the right to their own opinion, but not the right to their own facts.”


D-r Todorov’s claim that the data on mortality and morbidity for 100 000 people is “new mathematics” is not true. This is a standardized statistical indicator that allows for comparison of data. It is also not true that the metric for antibodies BAU/ml was introduced by “Big Pharma”. The metric was introduced by the WHO and its goal is to equalize the many and different metrics currently being used for measuring antibodies by different test producers. There is no clear evidence of the duration of immunity against SARS-CoV-2 after illness – antibodies decrease over time, but the dynamics are strictly individual and depend on many factors.

Translated by Lina Chakarova.

The publication has been produced with the support of NATO's Public Diplomacy Division. The responsibility for the content lies entirely with the editorial team of Factcheck.bg.

The publication has been produced with the support of NATO's Public Diplomacy Division. The responsibility for the content lies entirely with the editorial team of Factcheck.bg.

Bozhidar Angelov
Bozhidar Angelov
Bozhidar Angelov is a PhD student in EU media policy and law at the Department of European Studies at Sofia University “St. Kliment Ohridski”. His path in journalism began as an intern at BiT TV and the regional center of BNT (Bulgarian National Television) in Blagoevgrad. He was an editor in the media websites News.bg and Money.bg, and later he became a tv news anchor of the Money.bg show on Bulgaria ON AIR TV. The topic of the fight against misinformation and his interest in verifying the facts started from the US presidential election in 2016. A year later he defended his master's thesis on "The role of the media in limiting fake news (fact-checking)" in the master's program "E-Europe“.

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