What you’ve ever known about Covid-19 immunity-and what that means for vaccine boosters

And even if someone recovers from a previous infection and has innate immunity, vaccination can help boost their immune memory.

Vaccine maker to monitor immunity

Currently, three coronavirus vaccines are licensed for emergency use in the United States. A two-dose Pfizer / BioNTech vaccine for ages 12 and older. Two-dose Moderna vaccine for ages 18 and older. Single dose of Johnson & Johnson vaccine over 18 years old.

All three companies are investigating the potential use of boosters.

Vaccine makers also protect against long-term (eg, perhaps after a year or more) reduction in immunity elicited by these vaccines, and from coronavirus variants that may emerge and evolve. I am studying whether or not.

If so, vaccinated individuals may need booster doses of vaccine to remain protected from the original coronavirus strain and newly emerging variants-every 10 years. Similar to the method recommended for tetanus boosters, or different flu vaccines are recommended each year.

Still, doctors are worried that the coronavirus may become like the flu. Influenza requires a new vaccine every year due to the rapid mutation of circulating strains and the rapid weakening of the vaccine’s immunity.

“Therefore, cell-mediated immunity may help limit the severity of infections caused by mutants that partially escape neutralizing antibodies,” said the CDC.

Immunity can last much longer. Researchers just need time to evaluate.

The degree can be measured as to whether fully vaccinated people will eventually suffer from a higher proportion of breakthrough infections or severe infections that require hospitalization.

“For me, that’s the limit,” Adalja said.

On the other hand, studies of innate immunity due to previous coronavirus infections are proceeding somewhat longer than vaccine trials.

Latest findings on long-term immunity

Two new studies this week add to the growing evidence suggesting that innate immunity to coronavirus may be long-lasting after someone recovers from Covid-19-perhaps at least a year. But that doesn’t mean they shouldn’t be vaccinated. Nor does it mean that immunity lasts forever.

Bone marrow cells can retain Covid-19 memory for at least 11 months after someone is infected. These cells are the “essential” source of protective antibodies, according to a new study published in Nature.

Researchers at Washington University in St. Louis examined blood samples from 77 people previously infected with SARS-CoV-2, the virus that causes Covid-19. Researchers found the first reduction in the presence of Covid-19 antibody after infection, but the reduction slowed between 4 and 11 months.

The researchers also examined bone marrow samples taken from 19 previously infected patients about 7 and 11 months after infection. Researchers found the Covid-19 antibody in 15 of 19 patients. Unlike the observed reduction of other antibodies, the antibodies produced by the cells of the bone marrow appeared to remain stable.

However, he added, the findings do not suggest that people with Covid-19 no longer need to be vaccinated. Rather, vaccination may further enhance the natural immune response.

“I think vaccination is a big motivation because people who have been infected and have produced this beautiful memory for a long time can put these memory cells into action,” Elbedi said. He added that having does not mean a person. It is completely protected.

“Our data explain why people who experienced a mild SARS-CoV-2 infection last year are producing such a wonderful response to vaccination. It is the strong that they developed after infection. It’s for good immunological memory, “Ellebedy told CNN in an email Thursday.

“But not all previously infected people are the same,” he added. “For a variety of reasons, some people do not generate a strong immune response to the infection even after they have survived the infection. Therefore, it is best for people who have been vaccinated twice to receive both vaccinations.” ..

For the same reason (whether due to age or immunodeficiency), some people are advised to follow a different booster schedule in the future when booster shots are ultimately needed.

Nine out of ten people infected with the coronavirus develop innate immunity to the virus, which “persists with little decay” from the first infection to 10 months, researchers at the National Laboratory Labcorp conducted. EClinical Medicine research suggests.

Researchers found that approximately 90% of recovered Covid-19 patients tested in this study had detectable antibodies by 21 days after infection.

Researchers analyzed data from 39,086 people confirmed to have Covid-19 between March 2020 and January 2021, and at least in Labcorp after being positive for coronavirus infection. One antibody test was performed.

The data did not include patient demographics or information on the severity of certain Covid-19 cases.