Home / Health / What we know so far about COVID-19 immunity — and the implications of booster vaccines.

What we know so far about COVID-19 immunity — and the implications of booster vaccines.



It’s too early to tell But experts are close to cracking it.

“We will have to see how all of these interact. Could it be that we’re going to need a sponsor at some point? Yes, is that possible? Yes, we know exactly when, no,” said Marks. Maybe sooner or later Hopefully it will pass a year after getting the vaccine for the average adult.”

And experts emphasize that everyone currently fully vaccinated should be protected. But the reason why the timeline for the potential activator remains unclear is because scientists still need time to assemble it. Information about immunity to COVID-19 How long will it last in the future? and how to distinguish factors in the future

When a person is generally “immunized,” it means that they are protected against disease. Active immunity can be obtained through vaccination or infection. Your immune system develops antibodies produced by vaccination or in response to infection. And either immune response can preserve “memory.”
Immunity is usually measured by the presence of antibodies. This is a protein made by the immune system to help fight infection in the blood. This can usually be determined with laboratory tests. But the immune system is more than an antibody. They involve a host of players, including B cells, which produce antibodies, and T cells, which target infected cells.
Research has shown that both antibodies and T cells may recognize infection from pathogen variants, such as the novel coronavirus that is prevalent in the world today. which despite the important differences that may make it easier to spread But they are similar enough to recognized by the immune system’s memory

And although some people have recovered from previous infections and have natural immunity. Vaccination can also improve their immune memory.

immunization vaccine manufacturers

Three coronavirus vaccines are currently licensed for emergency use in the United States: two doses of the Pfizer/BioEntech vaccine for children 12 years and older; Two doses of Moderna vaccine for ages 18 and older; and a single dose of Johnson & Johnson vaccine for ages 18 and older.

All three companies are investigating the potential of using boosters.

COVID vaccine can fight new strains of virus  The results of the study revealed

Vaccine makers are investigating whether the immunity these vaccines produce may decrease over the long term, i.e. possibly after a year or longer. and whether they are protected by coronavirus strains that may appear and evolve.

if so Those who are vaccinated may need a booster vaccine to prevent infection with both existing and new coronavirus strains. This is quite similar to the recommended tetanus vaccination every 10 years, or a different influenza vaccination each year.

when talking about other viruses One measles usually leaves some people immune for life. The same was true for smallpox before the virus was eradicated in the 1970s by global vaccination campaigns. Proper vaccination against measles and smallpox can completely prevent infection.
But respiratory viruses such as influenza and coronavirus are more difficult. People can get the flu again and again. and in general The influenza vaccine only provides protection against some serious infections and illnesses. This is because there are typically several influenza viruses circulating due to mutations, although the coronavirus has a slower mutation rate than influenza.

Still, doctors are worried that the coronavirus will become like the flu. which requires a new vaccine every year both because the circulating species mutated rapidly. And because the immunity from the vaccine quickly wears off.

in the case of the coronavirus vaccine Several studies have assessed the immune response induced by Moderna and Pfizer vaccines to the original virus strain. and “these studies observed little or no defects in the cellular immune recognition of the variant,” according to a page on the U.S. Centers for Disease Control and Prevention website updated Thursday.

“Therefore, cellular immunity may reduce disease severity in some infections caused by variants that escape neutralizing antibodies,” according to the CDC.

It is difficult to predict how the reduced neutralization activity might affect the effectiveness of the COVID-19 vaccine, but studies have shown that The antibody neutralizing activity seen in fully vaccinated subjects was generally higher than that seen in those recovered from COVID-19.
How long will the coronavirus vaccine protect people?
Data from clinical trials suggest the protection offered by Pfizer and Moderna’s coronavirus vaccine would last at least nine months, the FDA’s Marks said in April. But experts have tried hard to point out that this does not mean that immunity stops at 9 months of age, meaning that the longest subjects were followed in the trial to see what their immunity was and collect data.

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

The medical community still needs data to determine which immune levels may decline over time, Dr. Amesh Adalja, a senior academic at the Johns Hopkins Center for Health Safety, who was not involved in the study, told CNN in an email on Thursday.

That level can measure whether a fully vaccinated person will eventually develop a more serious infection. or have an infection that is severe enough to require hospitalization

“For me that is the threshold,” Adalja said.

meanwhile Studies on the natural immunity from previous coronavirus infections have continued longer than relatively recent vaccine trials.

The latest research on long-lasting immunity

Two new studies this week add more and more evidence. that indicates natural immunity to coronavirus after a person has recovered from COVID-19 It may last a long time – maybe at least a year. But that doesn’t mean they shouldn’t be vaccinated. That doesn’t mean immunity lasts forever.

One study was published Monday in the journal Nature. Immune cells in the bone marrow of people infected with coronavirus have been found to have a “memories” of infection that can last a long time.
Other research published in the journal EClinicalMedicine on monday Covid-19 antibodies were found to remain detectable for about 10 months after the infection in people who had recovered.
Coronavirus immunity can last more than six months.

Bone marrow cells may keep memories of Covid-19 for at least 11 months after someone has been infected. These cells are a source of “essential” protective antibodies, according to a new study published in Nature.

Researchers from Washington University in St. Louis It examined blood samples from 77 previously infected people with SARS-CoV-2, the virus that causes COVID-19. Researchers found that antibodies to Covid-19 initially decreased after infection. But over four to 11 months, the decline slowed.

The researchers also examined bone marrow samples taken from 19 previously infected patients approximately 7 and 11 months after infection. The researchers found COVID-19 antibodies in 15 of the 19 patients, and unlike the observed reductions in other antibodies, the antibodies produced by cells in the bone marrow appeared to be stable.

Ali Ellebedy, study author and associate professor at Washington University in St. Louis, said: “That’s good news that these antibodies are created and maintained,” CNN’s John Berman told CNN on Thursday.

But he added that the findings did not indicate that people were infected with COVID-19. Vaccination is no longer necessary. On the other hand, vaccination can increase the natural immune response even more.

“I think people who are infected and create this beautiful memory over time. It would be a good incentive to get vaccinated. Because now you can put these memory cells to use,” Ellebedy said, adding that having antibodies doesn’t mean people. fully protected

“Our data explains why people who experienced mild SARS-CoV-2 infection last year produced impressive responses to vaccination. It’s because of the strong immune memory that developed after the infection,” Ellebedy told CNN in an email Thursday.

“however Not all previous infected people are the same,” he added. “For many reasons Some individuals do not produce a strong immune response to infection even after surviving the infection. Therefore, it is best for them to have both vaccines.”

for the same reason Either because of age or immunodeficiency. Some people may be advised to follow a different stimulant schedule in the future if boosters are eventually needed.

If you've ever been infected with COVID-19  Here's what you need to know about vaccines, strains, and more.

Up to 9 out of 10 people infected with the coronavirus develop natural immunity to the virus that “Remains with little decay” for up to 10 months after initial infection. said the study of EClinicalMedicine conducted by researchers at the Labcorp National Clinical Laboratory.

Researchers found that COVID-19 patients Approximately 90% of the recovered patients tested in the study had antibodies that were detectable within 21 days of infection. and the antibody rate remained around 90% considering some variance, up to 300 days.

Researchers analyzed data on 39,086 people who were confirmed to be infected with COVID-19. Between March 2020 and January 2021, and at least one antibody test was performed with Labcorp after a positive test result for coronavirus infection.

The data does not include patient demographics or information about the severity of specific COVID-19 cases.

Dr Brian Keffney, Chief Medical Officer and President of Labcorp Diagnostics, said: “Further research is needed to understand what types and levels of antibodies are recommended to prevent reinfection. “But the presence of certain antibodies for a long time is a good sign. As we continue to think about the safe spread of the epidemic including future vaccinations and the duration of booster injections.”

CNN’s Maggie Fox, Ryan Prior and Naomi Thomas contributed to the report.


Source link