Sunday, November 28

Reinfection from Covid-19 is rare, serious illnesses are even rarer, finds a study on people in Qatar – archyde

By Jen Christensen, CNN

When people became infected with Covid-19 again, their likelihood of ending up in hospital or dying was 90% lower than if they were initially infected with Covid-19, according to a new study.

The study, published Wednesday in the New England Journal of Medicine, found that among 353,326 people who contracted Covid-19 in Qatar, there were few confirmed reinfections and the reinfections were rare and generally mild.

The first wave of infections in Qatar struck between March and June 2020. In the end, around 40% of the population had detectable antibodies to Covid-19. The country then had two more waves from January to May 2021. This was before the more contagious Delta variant.

To see how many people became re-infected, scientists at Weill Cornell Medicine-Qatar compared the records of people with PCR-confirmed infections between February 2020 and April 2021. They excluded 87,547 people who received the vaccine.

The researchers found that among the remaining cases, there were 1,304 reinfections. The median time between the first illness and reinfection was about 9 months.

Among those with reinfections, there were only four cases that were severe enough to have to be hospitalized. There have been no cases where people were so sick that they had to be treated in the intensive care unit. Of the first cases, 28 were classified as critical. There were no deaths in the re-infected group, while there were seven deaths in the initial infections.

“When you have 1,300 reinfections and four serious illnesses among so many people, that’s pretty remarkable,” said John Alcorn, an immunology expert and professor of pediatrics at the University of Pittsburgh who was not involved in the study.

Studies have limits. It was carried out in Qatar, so it’s not clear if the virus would behave the same elsewhere. The work was done when the alpha and beta variants were the cause of many reinfections. There were 621 cases where it was undetermined and 213 from a “wild type” virus. The Delta variant, which is the predominant variety today, was not mentioned. This could affect the number of reinfections.

Previous studies have shown that natural immunity lowers the risk of infection. A study done in Denmark, which was released in March, found that most people who had Covid-19 appeared to have protection from re-infection that remained stable for more than six months, but a review of the demographics of people who became infected again showed that they were mainly people 65 and over. This study doesn’t make it clear how long the protection lasts, and neither does the new Qatar study.

Alcorn’s own research on natural immunity shows that antibody levels also vary significantly from person to person. Scientists still don’t know what level of antibody is protective, but in some cases post-infection levels may not be enough to keep someone from getting sick again.

“It needs to be determined whether such protection against a serious illness lasts for a longer period of time when it is re-infected, analogous to the immunity that develops against other seasonal ‘normal cold’ coronaviruses, which have short-term immunity against mild reinfection , but evoke longer-term immunity against more severe diseases with reinfection, ”the study says. “If this were the case with SARS-CoV-2, the virus (or at least the variants examined so far) could adopt a more benign infection pattern when it becomes endemic.”

Dr. Kami Kim, an infectious disease specialist not involved in this study, said people need to be careful not to get the wrong impression that people don’t need to get vaccinated if they have Covid -19 .

“It’s like asking the question, do you need airbags and seat belts?” Said Kim, director of the Infectious Disease and International Medicine division at the University of South Florida. “Just because you have airbags doesn’t mean seat belts won’t help you, and vice versa. It is good to have the protection of both. “

Kim said there was no point taking risks with the disease, especially because infection could have long-term effects. “The incidence of long-covid is much higher than the risk of getting a vaccine,” said Kim.

Vaccinations not only protect individuals from disease, but also the community.

“Modern medicine is much better, and people get cancer and survive, and autoimmune diseases and thrive. Unless you’re very close, you don’t always know who is more prone to more severe illnesses and you could literally put people you care about if you get sick and expose them, “Kim said. “You cannot go back to a normal life without a vaccination.”

Limiting the number of diseases also limits the potential for the development of more variants that could be even more dangerous than what is currently floating around.

Alcorn said there was another important lesson from this study.

“Vaccines are still our best way to get to the same place these infected people are, absolutely,” Alcorn said. “The main takeaway from this study here is that we hope that through vaccination and infection recovery, we will reach a level where everyone has some level of protection.”

The CNN Wire
™ & © 2021 Cable News Network, Inc., a WarnerMedia company. All rights reserved.

Leave a Reply

Your email address will not be published. Required fields are marked *