We are becoming more resistant to the coronavirus. Interesting research on American prisoners

Vaccinated people or those who have had a previous infection are less likely to pass on the Omikron variant to others compared to those who do not have developed immunity. The risk of further transmission is even lower in patients with dual protection from infection and vaccination. The study was conducted on 22 thousand. American prisoners.

1. The Omikron variant has dominated coronavirus infections since the beginning of this year. It started with the BA.1 sub-option, now it is BA.5
2. This is the most infectious variant to date. A recent study by scientists from San Francisco found that immunity acquired through vaccination or previous infection significantly reduces the risk of further transmission
3. This study shows that the more people are exposed to the virus, whether through vaccines, boosters or infections, the higher the immune wall, says Dr. Megan Stein, Australian virologist
4. More information can be found on the Onet homepage

How is Omikron spread?

At the end of August, a study (not yet reviewed) was published on the medRxiv website showing how vaccination and previous COVID-19 disease affect the further spread of the coronavirus.

The study was conducted by a team of scientists at the University of California, San Francisco, led by Nathan Lo, an infectious disease specialist. 22 thousand. cases of SARS-CoV-2 infection in 35 California adult prisons over a five-month period beginning in late 2021. During this time, the United States was experiencing the next largest wave of infections to date, initially dominated by the BA sub-variant. 1 Omicron, and at the end of April was superseded by BA. 2.

This is one of the first studies to show how Omikron spreads among people who are vaccinated or who have acquired immunity through a previous infection. Previous studies have looked at how the Delta variant behaves.

Vaccinations and past infection reduce the risk of further transmission

As it turned out?

People who were infected with Omikron, and were after at least one dose of the vaccine, infected another by 24 percent. less often than unvaccinated prisoners. Those who previously had an infection showed about 21 percent. less likely to pass the virus on. On the other hand, people who had immunity resulting from both vaccination and a history of disease continued to infect to a lower extent by 41%. compared to unvaccinated and previously uninfected people.

Each subsequent dose of the vaccine reduced the risk of further virus transmission by another 12%. It was important how long ago the preparation was taken. Every five weeks after vaccination increased the risk of transmission of infection by 6%.

“This discovery is good news,” said Dr. Megan Stein, a virologist at the University of Sydney, in an interview with the scientific journal Nature. – They show that the more people are exposed to the virus, whether through vaccines, boosters or infections, the higher the immune wall. If we manage to maintain a high level of booster vaccinations, we can reduce the rate of further infection from people with COVID-19, he explains.

What about the next variants?

Stein says the results from the California study are consistent with what scientists have known so far. But as more variants evolve, the way they cause infections may change.

– If some variants are able to replicate faster, they may be more infectious as higher viral loads are obtained in the nasal cavity. This may lead to thinking that it will amount to increased viral transmission, Stein says.

Earlier research on infectivity has often focused on households where the risk of transmission is lower than in tight prison cells. They were also carried out at a time when Omikron was not so common and concerned mainly unvaccinated people or only one dose of the vaccine.

According to epidemiologists, if studies in households were similar to those in prisons, it would provide an answer to how the virus spreads in the community. This would also apply to subsequent variants, as subsequent mutations are mostly different Omicron sub-variants.

Allen Cheng, an infectious disease physician and epidemiologist at Monash University in Melbourne, emphasizes that while the benefits of vaccination in reducing transmission diminish over time, it is optimistic to know that a prior infection can reduce transmission in the event of subsequent infection. Omicron, which is very difficult to control infections. We are pleased with any information that tells us something about this variant, says Cheng.