• health

• news

Corona vaccines no longer protect us?

Expert answers

Corona vaccines are not making headlines - from scary reports of a decline in their effectiveness to calls for a third dose to improve protection.

Dr. Oren Koviler from Tel Aviv University explains everything you really need to know at this stage of the epidemic

Tags

• Corona

• Vaccine for corona

Dr. Oren Kuibler

Monday, 26 July 2021, 07:16

• Share on Facebook

• Share on WhatsApp

• Share on general

• Share on general

• Share on Twitter

• Share on Email

0 comments

• Facts about the mind

• Six people drowned in 24 hours, 20 died by drowning since the beginning ...

• Egg separation

• The man with the largest organ in the world

• Corona Global: British Health Minister infected with Corona, ...

• How to arrange the bed

• Swimmer Fu Yuanhui

• A strange method of eating pizza

• The world's first toilet museum opens in South Korea

• Who and what dietary fiber

• A story in a flash The camera detected cancer in a baby's eye

• Facts about coffee

Bennett: "Those who refuse vaccines endanger our freedom" (Photo: GPO)

In recent days, there have been increasing voices supporting the administration of a third dose of the corona vaccine - why?

Aside from the fact that FDA approval has not yet been received for a third dose, I think it is still too early to talk about it for a number of reasons.

First, the efficacy of a third dose in corona prevention has not been proven.

Second, to prevent the formation of additional variants, populations that have not yet been vaccinated (in countries that do not yet have a regular supply of vaccines) should be vaccinated first.

But most importantly, it is not at all clear whether this vaccine is necessary.

More on Walla!

All the most up-to-date guidelines on corona insulation and testing

To the full article

This discourse on the administration of a third dose does not stem from field data, but from the fear that the vaccine has lost its effectiveness in preventing the spread of the disease.

Let us examine this claim.

The main cause of this concern is the number of people who were fully vaccinated and yet contracted the corona virus, and some even fell ill and died as a result of this infection.

The Ministry of Health recently announced that the effectiveness of the vaccine has dropped to 40 percent in preventing symptomatic infection among those vaccinated in January 2021. It is important to note that according to the Israeli Ministry of Health (which currently has lower vaccine efficiencies) Over 85 percent efficiency).

And this is what we need to keep in mind - this measure of minimal (if any) decrease in the effectiveness of the vaccine in preventing serious illness and mortality is obtained from all the vaccinated countries in the world, so I think the vaccine is still very effective in fulfilling its main purpose.

More on Walla!

• If vaccinated are infected with the Indian strain - why do they not need isolation?

• Researchers have discovered another unknown symptom of corona

• Saving from the first moment: How to start saving in four simple steps

So why do we still detect an increase in the amount of vaccines that become infected again?

The first and most important cause is the human factor.

The confidence we gained following the vaccine changed the way we behaved during the epidemic.

Large incidents in enclosed spaces, being in closed spaces without masks, trips abroad, etc. - all contribute to multiple exposure to the virus, and therefore to an increase in the number of infections even among vaccinated people. Vaccines have never claimed to provide one hundred percent protection, Contagious.

The real problem is the human factor.

Loads at Ben Gurion Airport (Photo: Reuven Castro)

The second reason is the large amount of vaccinated.

The greater the percentage of those vaccinated in the population, the greater the proportion of those infected at all.

If one hundred percent of the residents of the State of Israel were fully vaccinated, all those infected (because the vaccine does not protect one hundred percent) would be among the vaccinated.

Today in high-risk populations, we have reached over 90 percent vaccinated, so we see many more vaccinated who are hospitalized, and it is very difficult to treat the unvaccinated population as a representative sample of the general population.

In countries where the percentage of vaccination is lower, the effect of the vaccine is seen more easily.

For example, in May and June in the United States, the percentage of inpatients who were not vaccinated was over 99 percent.

The delta variant is not the main cause of the appearance of the current wave of infections

People who estimate that the decrease in vaccine efficacy is significant provide two possible explanations: the first argues that the vaccine is less effective against the delta variant, and the second claims that the vaccines have lost their effectiveness due to the time elapsed since vaccination.

The delta variant produces higher amounts of viral RNA in a shorter time from the moment of infection, which gives it an evolutionary advantage over the other variants, and therefore it increases in frequency in different regions around the world.

The variant contains a number of mutations in the gene that encodes the spike protein - the protein against which the immune response develops in the vaccinated and also the bulk of the immune response of those infected with the virus.

Therefore, antibodies formed in response to the original protein (as given in the vaccine) bind and neutralize the mutant protein less well.

The decrease in linkage ability has been seen in many studies so far, but in all of them the test was done in vitro only, and the decrease was not significant compared to the previous variants.

Delta is a variant with an evolutionary advantage, but the vaccine is effective against it.

Corona virus (Photo: Giphy)

In addition, it is important to remember that antibodies are just one arm of the immune system. Data from several countries show a decrease in the effectiveness of Pfizer vaccine in preventing infection and even in preventing serious illness, but according to most data from around the world - the decrease is relatively low (from 90 to 95 percent in preventing symptomatic infection in the alpha variant to 85 to 90 in the delta variant). Although there is a change in the effectiveness of the vaccine, in my opinion the Delta variant is not the main cause of the appearance of the current wave of infections.

A decrease in the relative amount of antibodies is observed as one moves away from the time of vaccination. This decrease is expected because our immune system does not maintain a high level of antibodies over time. Instead, our immune system retains memory cells that can wake up and produce specific antibodies on re-exposure. Therefore a natural decrease in the level of antibodies may allow infection, but not allow the development of a serious disease as a result. This may be why we are seeing more cases of vaccinated verified, but it is predictable, and unlikely to cause a burden on hospitals. In addition, it is biologically unlikely that there will be a sudden decrease in vaccine efficacy after several months, and a gradual decrease in this efficacy is expected so such a decrease may not be the cause of this outbreak.

In conclusion, the vaccine is effective and safe but can not be trusted as a single factor in neutralizing the epidemic.

Providing a third dose is a short-term solution that may impair the effort to eradicate the epidemic, as the human factor is still the leading factor in the increase in morbidity.

As long as the epidemic is raging in the world (without the vaccine of the rest of the world, the morbidity will not decrease significantly), we will also have to keep additional rules in order to prevent the spread of the virus.

The rules are quite simple: Anyone can go to get vaccinated, masks enclosed spaces, maintain user isolation cases properly and avoid as much as possible mass gatherings and international flights. If we follow these rules, we will return to a life of routine and open the regular school year.

Dr. Oren Koibler is a virologist and senior lecturer from the Tel Aviv University School of Medicine and a member of the "Madat" association.

• Share on Facebook

• Share on WhatsApp

• Share on general

• Share on general

• Share on Twitter

• Share on Email

0 comments