Have we been deceived as to whether the Corona vaccination will stop virus transmission? What the Pfizer boss and the vaccine study really said.
With the Covid-19 vaccination, the question of how much it slows down the spread of the virus is not so easy to answer.
After a hearing in the European Parliament a few days ago, the American pharmaceutical company Pfizer is accused of not examining important facts about the Covid 19 vaccines and misleading the public about their effectiveness. What happened? The company’s manager explained that the first clinical study had not tested whether the vaccine would protect against a vaccinated person picking up and passing on the virus despite being vaccinated. This has triggered a debate on social networks as to whether Pfizer faked this stop on transfers.
What is true about these allegations?
After the announcement of the first study results, the Pfizer boss and those responsible at the partner company Biontech pointed out several times that it was not yet possible to say whether the vaccine could prevent the virus from being passed on by vaccinated people. The first data from the vaccine study were published in November 2020 by press release presents. The detailed results were then published in the specialist magazine in December 2020 “New England Medical Journal”.
Because in the first phase of the study of the Covid-19 vaccine, it was recorded how many people in the group of vaccinated and how many in the comparison group of unvaccinated were infected with the virus. An effectiveness is calculated from this. In addition, the first phase of the study always records which and how many side effects occur in the months after the vaccination. The security is calculated from this.
However, whether people become infected despite vaccination and then pass on the virus can only be determined at a later point in time. Namely when the vaccination protection of many vaccinated people has decreased. If Pfizer and other vaccine manufacturers had waited for their studies to deliver these findings, then they and all of us would have had to wait much longer for the vaccine to be approved. According to the scenarios of some researchers, this would have meant that millions more people would have died of Covid-19.
Less virus transmission by vaccinated
However, based on experience with other vaccinations, there was hope that the Covid-19 vaccines would protect against virus transmission by vaccinated people for at least several months. There are plausible biological reasons for this.
If you find out that a vaccinated person is protected from an infection, this means biologically: Even if he is coughed up with a torrent of viruses, there is no or at most very little multiplication of the viruses in his body. This is prevented by the specific antibodies triggered by the vaccination. And if someone does not multiply viruses in himself, he cannot emit contagious particles either.
After the start of the global vaccination campaign in January 2021, several countries analyzed the blockade of virus transmission by vaccinated people in their populations. There were various reports from Great Britain, one of the first publications on this is a study from Israel, which was published on July 7, 2021 in the specialist magazine «The Lancet» has appeared. It was found in each case that the vaccination “significantly reduces” the transmission of viruses by vaccinated people in the first few months after vaccination. But not completely blocked.
This is because some vaccinated people get sick. And in others, despite vaccination, a small amount of virus can multiply. The person does not get sick, but can pass on viruses.
Arguments for the Swiss Covid certificates
At the beginning of June 2021, Switzerland started issuing Covid certificates for vaccinated, recovered and tested people. The Federal Council had created the legal basis for this with an ordinance. In September, he extended the certificate obligation until the end of January 2022. It now applied to the interior of restaurants, cultural and leisure facilities and indoor events.
At that time, the Federal Council reacted to the persistently tense situation in the hospitals. The intensive care units in particular were very busy. In some cantons, operations had to be postponed and patients transferred to other hospitals. In addition, due to the seasonally lower temperatures, another large wave of infections and thus an escalation of the situation was a realistic scenario. This is also because the proportion of the non-immune population was still large.
In September 2021, the Federal Office of Public Health (BAG) wrote as a reason for the obligation to have a certificate: “Because this only brings together people who are not contagious or who have a low risk of being contagious, the risk of transmission is greatly reduced.”
This statement is consistent with the Assessment that the scientific Covid-19 task force in Switzerland made in a “Policy Brief” at the end of June on the effectiveness of the vaccination. After two doses of an mRNA vaccine (Pfizer/Biontech or Moderna), people under the age of 75 have “50 percent protection against mild disease for 16 months and 80 percent protection against severe disease for three years”. In older people, the duration of the protective effect is estimated to be somewhat shorter.
According to the task force, these estimates are based on studies that have shown that the concentration of specific antibodies decreases after a corona infection or a vaccination with a half-life of around one hundred days: “Researchers estimate that around 20 percent of the initial antibody response after the infection are required to provide 50 percent protection against the risk of reinfection and mild illness (. . .)» According to the task force, based on the available data, a validity period of twelve months after full vaccination is scientifically justifiable.
What is striking: The task force writes about the risk of reinfection and a mild illness after vaccination (which is not always easy to distinguish in everyday life) and not about whether the vaccination prevents the virus from being passed on by vaccinated people. In technical jargon, such a blockage is referred to as sterilizing immunity. (However, this does not mean that the vaccination makes you infertile.)
Certificates can be useful in a pandemic
With the Covid-19 vaccination, the question of how much it slows down the spread of the virus is not so easy to answer. In theory, sterilizing immunity means that the virus can no longer infect the person – that is, the pathogen can not enter the organism and multiply there. In this case, the virus cannot be passed on either: the protection is complete.
The corona vaccination does not offer such 100% protection. Protection also decreases over time, but this also means that protection against infection and mild illness is higher shortly after vaccination (or after infection) than if no immunization occurs at all. Overall, fewer viruses are passed on.
This is an important reason why the obligation to have a certificate can make sense from an epidemiological and public health perspective in a pandemic crisis like the one in autumn 2021. This is because the number of infections can be reduced (“flatten the curve”) and the health system can be protected from acute overload.