Antibodies in no-shot Covid survivors 'stronger' than two-dose protection, study claims

Antibodies in no-shot Covid survivors ‘stronger’ than two-dose protection, study claims

The study suggests that people who had Covid but were not vaccinated may have longer-lasting immunity than those who received the double shot but never got infected.

Throughout the pandemic, there has been a fierce debate about whether natural or vaccine protection is better, and research has yielded mixed results.

As time went on, the discussion became more complicated because so many people were exposed to the virus and received vaccinations.

The latest study from Israel looked at more than 500 people who either just contracted the virus or recently received two shots between 2020 and 2021.

Participants were followed for a year and had regular blood tests to measure their antibody levels and strength of protection.

While those who were vaccinated initially had higher levels of antibodies, they dropped much more sharply than those in the naturally infected group.

Six months later, the pre-infection group also had “stronger” antibodies, an indication of how well they bind to the Covid spike protein when the virus enters the body.

Experts say no decision has yet been made on which type of immunity is best, but almost all scientists agree that a combination of a vaccine and natural protection is the best.

Research conducted by experts at the Sheba Medical Center in Ramat Gan, Israel has shown that people who have had Covid but have never been vaccinated have longer immunity than those who have received a double shot but have never been infected. .  The graph shows: Patient antibody avidity - how well infection-fighting proteins attach to the target virus - after natural infection (red) or a second vaccination (blue).

Research conducted by experts at the Sheba Medical Center in Ramat Gan, Israel has shown that people who have had Covid but have never been vaccinated have longer immunity than those who have received a double shot but have never been infected. . The graph shows: Patient antibody avidity – how well infection-fighting proteins attach to the target virus – after natural infection (red) or a second vaccination (blue).

The study, conducted by Sheba Medical Center Ramat Gan, only looked at antibodies that are part of the complex immune response to Covid.

The immune system also includes T cells and other white blood cells, which are harder to measure but may provide longer-term protection, especially against severe consequences.

The study was also conducted when Israel was dominated by the original Wuhan and Alpha strains, so results may not necessarily reflect immunity against later variants such as Omicron.

But a study by Maccabi Healthcare and Tel Aviv University in Israel last August also found that natural immunity is better at preventing delta infection — up to 13 times.

Vaccinating children aged 5 to 11 against Covid “won’t make a big difference” because most of them have natural immunity.

The scientist said that it is pointless to give Covid injections to healthy children of primary school age, because most of them have already suffered a weak strain of Omicron and have recovered.

Vaccine Advisory Group 10 is expected to announce injections for children aged 5 to 11 this week.

Currently, only children in this age group who are clinically vulnerable to the virus or who live with a relative are offered the Covid vaccine.

However, as other countries such as the US and much of the EU already approve vaccinations for children over 5 years of age, there has been pressure on the UK Joint Committee on Vaccinations and Immunizations (JCVI) to follow suit.

But Professor Paul Hunter, an infectious disease expert at the University of East Anglia, told BBC Radio 4’s Today program that “the point is now past” when giving shots to children aged five to 11 “would make a big difference.” .

His comments were backed up by today’s Office for National Statistics report that as of January 10, nearly three-quarters of children aged 8 to 11 already had antibodies to Covid.

Healthy children face a vanishingly low risk of becoming seriously ill with the virus, with only six healthy children dying from the virus in the first year of the pandemic in England.

And two doses of an injection provides just 10 percent protection against infection with an antibody-resistant variant of Omicron, UK data show.

In the latest study, none of those who were initially infected became re-infected during the study, and those who were injected did not subsequently become infected with the virus, suggesting that both had high levels of immunity.

The experts recruited 130 people who were infected between March and November 2020 and had not been vaccinated by April 2021.

They also studied 402 people who received a second shot at the end of 2020 but never had the infection.

At the time, Israel led the world in introducing the vaccine.

The experts measured the levels of antibodies in the patients’ bloodstream immediately after being infected or given a vaccine and tested again six months later.

The researchers also measured antibody avidity — how well infection-fighting proteins attach to the target virus.

Those who were vaccinated initially had higher antibody levels as well as higher avidity.

But six months later, in the “never had coronavirus” group, both rates fell to lower levels than in the unvaccinated cohort.

Meanwhile, in those infected, the level of antibodies decreased more gradually.

In fact, greed increased after six months, although the researchers cannot explain why.

The results are due to be presented at the European Congress of Clinical Microbiology and Infectious Diseases conference in Lisbon, Portugal in April.

In their study, the researchers stated: “While the number of antibodies decreases over time in both recovered from Covid (but never vaccinated) patients and in vaccinated (but never infected) people, the quality of antibodies increases after infection, but not after vaccination.”

They said future studies should investigate whether people infected with previous variants have greater protection from Omicron.

Dr. Karmit Cohen, an epidemiologist at Sheba Medical Center who led the report, said: “Vaccination with the omicron variant better protects people from serious diseases.

“I think the most interesting thing right now is to see those people who recovered from earlier variants and then re-infected and recovered from infection with the Omicron variant.

“Hypothetically, these people should have very high antibody efficacy against most variants.”

Independent experts said there is “still no decision” on whether natural immunity provides stronger protection against the virus.

At the time, Israel led the world in vaccine adoption, infecting 11 percent of the population by December, when the UK had just begun rolling out the first doses to the most vulnerable, reaching 1 percent of the population by the end of the year.  month.  Pictured: A man receives his fourth dose of the vaccine in Tel Aviv, Israel on January 3 this year.

At the time, Israel led the world in vaccine adoption, infecting 11 percent of the population by December, when the UK had just begun rolling out the first doses to the most vulnerable, reaching 1 percent of the population by the end of the year. month. Pictured: A man receives his fourth dose of the vaccine in Tel Aviv, Israel on January 3 this year.

Professor Danny Altman, an immunologist at Imperial College London, said: “This study touches on some of the difficult unknowns that we all face in human immunology research at this stage of the pandemic.

“While the opinion of other studies suggests a better quality of response, as measured by B-cell receptor breadth and affinity maturation by vaccination, this study, in contrast, reports something that is described as an improvement in antibody levels following infection.

“Definitely work is ongoing, consensus is needed, and much remains to be done.

“In terms of consensus on the quality, quantity, and longevity of protective immunity after peak exposure to infection, vaccination, or hybrid exposure, the jury is still out.”

Dr Julian Tang, a clinical virologist at the University of Leicester, said: “Typically, natural infection elicits a wider and longer set of immune responses to all viral antigens, so this is not surprising.

“After all, our immune systems have evolved over several million years to deal with all types of pathogens, so I expect natural immunity to outperform any vaccine-induced immunity in the long term.”

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