The resurgence of the epidemic does not call into question the effectiveness of the vaccines
If Belgium is facing a fourth wave, it is not because vaccination is proving ineffective. Despite the action of time and the aggressiveness of the Delta variant.
Such is the essence of shortcuts: while they are generally tempting, they can turn out to be messy. So it is with this one: since Belgium is facing a fourth wave of this interminable coronavirus epidemic while 87% of its adult population is fully vaccinated, this is proof that vaccines do not work – or at least more, or not enough, against this more aggressive Delta variant.
“It’s a bogus trial!», Insists Jean-Michel Dogné, director of the pharmacy department of UNamur. It is not because vaccination, alone, does not contain the Delta variant, that it is defective – and this even if the need to accompany vaccination with other measures has tended to be ignored from political discourse. There is no lack of studies to prove it.
Protection maintained
Point it out UK surveillance. Rather reassuring news emerges about vaccine efficacy under Delta’s reign. Against infection, AstraZeneca provided protection between 60% and 70% and Pfizer, 75% to 85%. Against a symptomatic form of Covid-19, these results climb, respectively to 65% -75% and 80% -90%, to which is added the score of more than 90% of Moderna. With regard to hospitalizations and deaths, we are systematically above 90%.
“In general, less than 80%, or even 90%, protection against severe forms contacting each other.”
As for those who appreciate the diversity of sources and studiess, the monitoring carried out by the World Health Organization (WHO) and the International vaccine access center should please them, since it brings together, in what is called “forest plots”, the results of a package of studies. What does it come out of? that yes, we notice a decrease in performance against infections over time. But decline does not mean disappearance, since the results are often in the range of 55% to 75% and up to 90% for Pfizer or Moderna. And this, with Delta on the menu.
Better, adds Jean-Michel Dogné. If this phenomenon of erosion also affects the rampart against hospitalizations and deaths, it is to a lesser extent. “In general, less than 80%, or even 90%, protection against severe forms contacting each other.”
We are also starting to have first Belgian data. Take with a grain of salt, warns Sciensano. Because the harvest is recent. Because you do not wait 14 days after the final injection to consider a person as fully vaccinated. Finally, because a more detailed analysis according to the type of vaccine or individual factors is announced. But there is talk of a reduction in the risk of hospitalization of 60% for those 65 and over, 86% for 18-64 years and 100% for 12-17 years.
“There are a lot of vaccines that require three doses. For example against hepatitis B or the combination of tetanus and diphtheria.”
Which brings us to the question of the “booster” and injecting an additional dose. Because studies, especially the one published in early November in Science, tend to show that the loss of effectiveness is greater in the elderly or those who have received a single dose of Johnson & Johnson. This explains, in Belgium, the positioning of the Higher Health Council in favor of a “booster” dose for people over 65, those active in health care or having received a single dose.
Booster that begins to show interest, both against severe forms (in Israel) and against infections (UK). And is part of a rather classic vaccination scheme, argues Nicolas Dauby, expert in infectious diseases at CHU Saint-Pierre. “There are a lot of vaccines that require three doses. For example against hepatitis B or the combination of tetanus and diphtheria.”