Posted on Jan 3, 2022, 1:47 p.m.
At the rate of more than 200,000 positive cases detected every day, will we all catch the coronavirus?
No, because vaccination plays its role despite the explosion of cases . The incidence in the elderly is also five times lower than in young adults, and the goal is that these elderly do not encounter Omicron. So there will be a rise in natural immunity, but not all of us will get the virus.
Is Omicron inherently more transmissible, or is it just an advantage over Delta because it is more resistant to vaccines?
Theoretical evidence suggests that it combines these two qualities. Of the thirty or so mutations observed, some promote receptor binding and replication, which increases the performance of the virus, which is called “fitness”. Other mutations promote vaccine escape – with less protection by antibodies, but all the same preserved cellular immunity.
With this variant, the incubation time is shorter and the contagious phase shortened?
Yes, the replication is faster. So everything gets shorter, including the symptomatic phase – or asymptomatic but contagious. The challenge is to be able to reduce eviction times for infected people, in particular for healthcare professionals. This feature facilitates decisions to shorten the duration of isolation . The United States reduced it to 5 days for positive patients, which is very little.
87% of the population had to be protected to create collective immunity with Delta. What regarding with Omicron?
All adults must have received their third dose! And besides, teenagers too. We proposed to the Vaccine Strategy Orientation Council that they become eligible. It shouldn’t be long, as it’s an effective way to reduce viral circulation. As for adults, there have already been 23 million recalls. It’s not bad, but we must move forward as quickly as possible, at a forced march . There remain 27 to 28 million first-time vaccinees who have not been recalled. I really hope that we will succeed in passing the milestone of 7 million vaccinations per week in January.
How to do ? We came close to the daily million before Christmas, but since then the enthusiasm has subsided a little …
I find that 400,000 to 500,000 vaccinations a day between Christmas and New Years is pretty good. The vaccinators have the right to breathe, and the vaccinated to think of something else during this period. The same dip was observed among the British.
In January, I count on a growing participation of general practitioners. Today, they are put off by the weekly ordering procedure for vaccines, but they can also arrange with their pharmacist and take doses at the pharmacy. In vaccination centers, the number of vaccinators can be further increased by resorting to first-level rescuers. It’s so important to go fast.
There were 700,000 first injections in December, but there are still 5 million unvaccinated. How many will be able to be convinced, or affected by the “go to” operations?
It’s impossible to say! In any case, the small increase in the number of primary vaccinations in December is correlated with the announcement of the vaccination pass. It’s essential.
How does the vaccination campaign for 6-11 year olds start?
My 6 and a half year old little girl has just received her first injection! There are still very few children vaccinated, around 20,000 since December 20, it was predictable. I expect a take-off in January, because the vaccination centers will have set up their pediatric lines.
The emergency is frail children, who represent 20 to 40% of pediatric hospitalizations for Covid. Growth will not be explosive. There is a reluctance of parents, but they will realize during the first trimester that the vaccination is harmless and effective, as a year ago when we started vaccination of adults. I hope we will protect at least half of the children. It is also necessary to go beyond 80% for adolescents.
How well does the third dose protect once morest Omicron?
The booster reduces the risk of infection by 70-75%. We do not yet have very precise data on the protection once morest the risk of severe forms, but we can think that it reaches 90%. Let us not forget, however, that Delta is still there, that it is more aggressive, and that vaccine protection is even greater once morest this variant, when the booster is combined with the primary vaccination.
What good is it, if vaccine protection decreases very quickly?
Indeed, a British study suggests that protection once morest infection is falling rapidly, but this remains to be clarified. This is a key point to follow very closely to adapt the strategy to fight once morest the epidemic.
In the short term, it is obvious that a massive recall campaign is the best weapon to slow down the wave and to prevent it from turning into hospitalizations. The Pasteur Institute ; It’s not nothing. This justifies the decision to shorten the time between the second and the third dose to three months: admittedly, a longer interval would amplify the immune response, but the priority is to vaccinate now, and the three months have opened up the booster to 5 million more people.
Israel already wants to launch the campaign for the fourth dose … Is there not a risk if we accumulate revaccinations every quarter?
Israel faces a particular problem: this country is constantly ahead of the rest of the world in terms of vaccination, but the third dose seems to have reached a plateau, just over 60% of eligible patients.
Medically, there is no risk of tolerance to vaccinate every three or four months. The real risk is the weariness of the French and social acceptance. It will be necessary to decide according to two factors: the duration of protection once morest Omicron, weighted by the intensity of the viral circulation, and the prospect of the arrival of specific vaccines once morest this variant. In the immediate future, we have enough to keep the health system busy with the latest primary vaccinations, massive booster shots and childhood vaccinations.
The vaccines targeting Omicron are due to arrive in March, can we not find universal vaccines so that we no longer have to run following variants?
Researchers are trying to develop a universal vaccine, but influenza efforts have never succeeded. We will probably first have specific vaccines once morest Omicron. And we now know that having had Omicron induces a very strong immune response once morest Delta. It is not excluded that the combined vaccines for several variants will also arrive very quickly, because the laboratories have been working on them for a long time: the “wild” virus plus Beta, Delta plus Omicron, etc.
On the other hand, the non-messenger RNA vaccines that are announced, Novavax, Valneva, Sanofi will probably be a little less effective and will not be on the front line.
Are we better protected when we have been fully vaccinated, or when we have been infected?
I would say the combination of the two provides the best response in terms of antibodies. The natural infection generates a local immune response in the nose, throat, perhaps the bronchi, where it begins, which vaccination does not allow. But vaccination confers very strong pulmonary protection, and therefore makes it possible to fight effectively once morest severe forms.
With Omicron, which seems less serious, young people in good health may be tempted to allow themselves to be infected in order to “strengthen their immunity” …
First, you don’t strengthen your immune system with an infection. Immunity remains targeted. Then, even when you are young, you are not immune to serious forms, and Omicron is not trivial. I also draw attention to collective solidarity: each young person vaccinated reduces the risk of transmission to the elderly or to 200,000 to 300,000 immuno-depressed French people. Do not underestimate this risk and play as a team.
What do we know regarding the severity of Omicron, precisely?
South African, British and Danish studies converge to say that Omicron reduces by a factor of 2, or even 3 or 4, the number of hospitalizations. It’s enormous. We are already certain that it is less severe than Delta; maybe also less than its predecessor Alpha.
How many times can we re-infect ourselves?
Some people have already become infected two or three times. But most often, these are mild forms, except in fragile people. It is possible that Omicron marks the beginning of an evolution towards less severe variants. So history will gradually shelter us.
We hoped a few months ago that the coronavirus was in an evolving dead end; Omicron has showered our hopes by taking different branches and combining a multiplicity of mutations. It cannot be predicted that the virus has exhausted all of its mutational capacities. Nevertheless, if the selection of the virus continues to be made by better transmission, it is not excluded that we are at the first stage of an evolution towards less severe forms.
