Coronavirus Covid 19: study shows that unvaccinated individuals could be re-infected every 16 months

Unvaccinated people could expect to be re-infected with Covid-19 about every 16 months due to decreased immunity, a study found.

The Yale School of Public Health analyzed data on coronaviruses similar to Covid-19, including SARS-CoV-1 and Middle East respiratory syndrome (MERS-CoV), to estimate the likely reinfection rate for Covid .

Despite growing reports of reinfection for Covid-19, the numbers are still not high enough for a proper study, so scientists have analyzed data from similar diseases to predict how long immunity will last.

Research published in The Lancet Microbe this month estimated that immunity in those who contracted Covid-19 weakened fairly quickly.

Yale research associate Hayley Hassler, one of the study’s co-authors, told Yale Daily News that the risk of re-infection was around 5% three months after the initial infection, and that ‘it dropped to 50% after 17 months.

People could be re-infected between three months and five years – with a median of 16 months.

The numbers assume that Covid is circulating in the community and that no restrictions such as masks or social distancing are in place.

The study also noted that immunity could vary widely from individual to individual, this could depend, for example, on whether the person was asymptomatic, which could produce a weaker immune response than if they were showing symptoms. .

“Individuals can experience shorter or longer durations of immunity depending on immune status, cross-immunity, age and several other factors,” Hassler said.

As the pandemic continues, scientists believe reinfection is likely to become more and more common.

The study notes that maintaining social distancing measures, even for those who have already been infected, and accelerating vaccination around the world would be essential to prevent deaths.

“We have to be very aware that this disease is likely to circulate in the long term and that we do not have this long term immunity that many people seem to hope to rely on to protect themselves from the disease.” said Jeffrey Townsend, professor of biostatistics at Yale and lead author of the study.

The results are also important for achieving collective immunity. The study “strongly opposes” any attempt to achieve this without vaccination.

“Relying on herd immunity without widespread vaccination puts millions of lives at risk, leading to high rates of reinfection, morbidity and death,” the study said.

In areas with low immunization, the study highlights the need for continued social distancing, good indoor ventilation, and wearing a mask to prevent re-infection.

“The main implications are that if you haven’t been vaccinated you should get the shot, and if you’ve been infected you should still go ahead and get the shot, as this will prolong the duration of your protection. “Townsend told the Goalkeeper.

It comes as research published in The Lancet this month found that two doses of the Pfizer vaccine were 90% effective against hospitalization for all variants, including Delta, for at least six months.

However, protection against infection with Delta fell from 93% at one month to 53% after four months.

Efficacy against hospitalization remained high, at 93 percent, over the eight months of the study.