Scientists have learned how unvaccinated against Covid-19 threaten the safety of vaccinated

(ORDO NEWS) — Simulations by Canadian researchers have confirmed that not vaccinating puts those who are vaccinated at risk of contracting the coronavirus. Therefore, the decision to vaccinate or not cannot be considered a personal matter for everyone.

Although many opponents of vaccination consider vaccination a personal matter for everyone, their choice affects those around them.

And, as simulations by scientists at the Dalla Lana School of Public Health at the University of Toronto (Canada) have shown, not being vaccinated against Covid-19 disproportionately increases the risk of coronavirus infection for those who got the shot. And to a greater extent than one would expect, based only on the number of contacts.

When making a decision not to be vaccinated, a person, according to scientists, usually does not take into account the potential harm to society as a whole. Meanwhile, its refusal leads to increased transmission of the virus among the unvaccinated, and the infectious nature of the disease means that it increases the chances of infection for the vaccinated as well.

In a normal community, such groups inevitably come into contact with each other, and one should not forget about the airborne nature of the spread of SARS-CoV-2 and its ability to persist on surfaces. That is, close physical “mixing” of vaccinated and unvaccinated is not necessary for disease transmission.

To better understand the implications of interactions between vaccinated and unvaccinated, Canadian scientists built a simple compartmental model with two related subpopulations: people who got vaccinated against coronavirus infection and those who didn’t.

They were divided into three possible groups: those susceptible to Covid-19 (those who had contact with the sick), infected and contagious, and those who were immune to the virus (those who had been ill and vaccinated).

“We have received simulated epidemics that assume a different number of contacts (mixing) between vaccinated and unvaccinated groups. At 20% baseline immunity among the unvaccinated and 80% of the vaccinated population, it turned out that the absolute number of cases in these two groups was the same when randomly mixed.

However, after we adjusted for the significantly higher number of people who were vaccinated, the risk of infection became markedly higher among those who did not get vaccinated. With more frequent “mixing” with their own kind (contact with other people with the same vaccination status. – Note ed.), the differences in incidence between vaccinated and unvaccinated groups became more obvious, and cases among the unvaccinated accounted for a significant proportion of infections, ”the authors write work.

When the unvaccinated came into contact with their own kind, the risk of infection was lower for the vaccinated. However, if vaccinated and non-vaccinated are mixed in, a significant number of new cases of Covid-19 would be among the vaccinated, even if vaccination rates in society were high.

That is, the vaccinated reduced the incidence rate among those who did not get the injection, acting as a buffer for the transmission of the virus.

The results remained the same even when the model accounted for lower vaccine efficacy, new strains of the coronavirus, or those who did not get boosters.

“As the mixing of like with like increased, the incidence rates among the vaccinated decreased from 15% to 10% (and increased from 62% to 79% for the unvaccinated), but the unvaccinated contributed more to the incidence of those who were vaccinated. degree than could be expected,” the scientists stressed.

In their opinion, since the refusal to vaccinate also puts those who have been vaccinated at risk of infection, the question of this cannot be considered a “personal matter for everyone”: as a result, the decision affects not only the person himself, but also those around him – both relatives or acquaintances, and strangers.


Contact us: [email protected]

Our Standards, Terms of Use: Standard Terms And Conditions.