Friday , May 14 2021

RIVM: “US study does not show that vaccines prevent the transmission of viruses”

For a moment, the coronavirus did not completely dominate the news. The focus has been on The Hague politics, but the crisis of the crown continues. The inconvenience surrounding the vaccination campaign has also attracted attention. There was also positive news from this front.

Among other things, NOS spoke with Jaap van Dissel, director of the RIVM Infectious Disease Control Center (CIB), and Jacco Wallinga, chief modeler of the same RIVM.

There was good news this week about vaccinations from the US. The Pfizer / BioNtech and Moderna vaccines not only protect well against covid-19, but also appear to significantly reduce the risk of transmitting the virus.

Van Dissel: “Well, this research doesn’t really say anything about it. The study looks at the extent to which the vaccine offers protection against the covid-19 convention. “These risky effects – because they are – you see that these people are very well protected after vaccination. But it has not been measured whether the vaccine restricts the transmission of the virus.”

Is the answer to this study very positive?

Van Dissel: “This is a great study, with promising preliminary results. But the interpretation given by NOS goes a long way. The study proves that these vaccines are effective against diseases. You have previously argued that vaccination prevents transmission is justified. on the basis of such research. “

“In addition, it was examined whether people vaccinated with the throat virus had complaints. This almost always happened, except for more than 10 percent. These results are in line with previous studies in Israel and the United Kingdom, for example.” But this does not happen. The same as showing that vaccination really reduces the transmission of the virus, that is, it prevents you from infecting someone else. That was not the purpose of the study. “

So what are the limitations of the study?

Van Dissel: “This is a cohort study of caregivers, firefighters, etc. To show that vaccination also reduces transmission, you have to prove that one vaccinated person actually infects fewer people, in a natural environment where “You also come across unvaccinated people, which has not been investigated and certainly has not been proven.”

Of the 3,950 participants in the CDC study, 72% were between the ages of 18 and 49 and 62% were women. In addition, 86% of the research team was white. It is not a representative choice of the US population. Does this affect eloquence?

Van Dissel: “It’s a promising study because it shows that the virus occurs less often in vaccinated people, but there are several explanations for this. For example, a cohort effect: in one environment everyone is vaccinated and so you cough less at each other. “Your own virus-free bubble. In addition, the research was also quite limited in age groups. There were very few seniors among them.”

“We know from a Danish study published two weeks ago in the scientific journal The Lancet that among these older people, at least in Denmark, a second infection occurs quite often despite the previous first infection. At least more often than in younger groups. “

You have many comments.

Van Dissel: “Again, it’s really a good study, but you always have to watch critically: what exactly does it say and what conclusions can we draw?”

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