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When Jonathan Isaac, one of the Orlando Magic’s top basketball players, explained why he chose him not be vaccinated It touched on a dispute that has been boiling for months against the coronavirus: people with Covid-19, As Mr. Isaac saidDo you really need the vaccine?
This question has introduced convoluted immunological concepts into a national debate over vaccine imperatives. politicians, athletes, law professors and psychiatrists to give weight to the relative strength of so-called natural immunity against the protection afforded by vaccines.
But like nearly everything virus-related, the answer is complex.
While many people who have recovered from Covid-19 can survive a second encounter with the virus relatively unscathed, the strength and durability of their immunity depends on their age. health situation and seriousness initial infection.
“That’s the thing with natural infection — depending on what type of disease you develop, you could be on the very low end of it or on the very high end,” said Akiko Iwasaki, an immunologist at Yale University.
Those with strong natural immunity may be protected from re-infection for up to a year. But experts said they shouldn’t skip the vaccine. For starters, boosting their immunity with a vaccine can provide long-term protection against them. all variants.
“If you’re infected and vaccinated, you have superpowers,” said Jennifer Gommerman, an immunologist at the University of Toronto.
Without this increase, antibodies from an infection will decrease, leaving people who have recovered with Covid vulnerable to re-infection and mild illnesses with variants, perhaps prone to spreading the virus to others.
That’s the same argument for giving boosters to fully vaccinated people, said Michel Nussenzweig, an immunologist at Rockefeller University in New York. “After a certain period of time you will either become stronger or infected,” he said.
It is difficult to parse how immunity from infection and vaccine compare. Dozens of studies have delved into the debate and produced conflicting conclusions.
Some consistent patterns have emerged: Two doses of mRNA vaccine produce antibodies more and more reliably than coronavirus infection. But antibodies from previous infection more diverseIt has the ability to fend off a wider range of variants than those produced by vaccines.
Studies suggesting the durability and strength of natural immunity are hampered by a crucial flaw. By definition, they only evaluate responses from people who have recovered from Covid-19. Dr. Nussenzweig said the road to natural immunity is dangerous and uncertain.
Only 85 percent to 90 percent of people who test positive for the virus and recover have detectable antibodies at baseline. The strength and durability of the reaction are variable.
For example, immunity from vaccines and infection was comparable among younger people, while two doses of mRNA vaccines were maintained. Adults over 65 better than a previous infection.
Dr. Research published in May by Iwasaki’s team, gradual increase at the level of antibodies with increasing severity of infection. About 43 percent of those who recover was not detectable neutralizing antibodies – the kind needed to prevent re-infection – according to one study. antibodies falling to undetectable levels About 30 percent of people recover after about two months.
Fikadu Tafesse, an immunologist at Oregon Health and Science University, said other researchers may find different results depending on the severity of the disease in the participants.
Dr. “I think the chances of having a detectable antibody are higher if your cohort consists of only hospitalized individuals,” Tafesse said.
In terms of the quality of the antibodies, it makes sense that an invasion of a live virus would produce a broader immune response than injecting the single protein encoded in vaccines, he and others said.
While vaccines mainly produce antibodies in the blood, the virus activates defenses in the nose and throat – exactly where it is needed to prevent a second infection.
Dr. “This will give you an advantage in terms of resisting a subsequent infection,” Gommerman said.
Pieces of the virus can remain in the body for weeks after infection, giving the immune system more time to learn to fight the virus, while the proteins carried by the vaccine quickly leave the body.
Many studies has now shown that at least previous versions of the virus, rare.
None of the 1,359 healthcare professionals at Cleveland Clinic who is unvaccinated An infectious disease physician at the clinic, Dr. Nabin Shrestha stated that Covid-19 happened after testing positive for the virus for months.
But he acknowledged that the findings should be interpreted with caution. The clinic only tested people who were visibly sick and asymptomatic who might have been reinfected. Participants were 39 years old on average, so the results may not apply to older adults who are more likely to be reinfected.
Dr. Shrestha noted that most studies only tracked people for about a year. “The important question is how long it protects, because we don’t have any illusions that this will be a lifetime protection,” he said.
It is also unclear how well immunity after infection protects against newer variants. Most studies ended before the Delta variant became dominant, and more recent research is patchy.
What You Need to Know About Covid-19 Booster Shots
FDA authorized booster shots For a selected group of people who have received their second dose of the Pfizer-BioNTech vaccine at least six months ago. This group includes: Pfizer recipients aged 65 and over or living in long-term care facilities; adults at high risk of serious Covid-19 due to an underlying medical condition; healthcare workers and others whose jobs put them at risk. with people weakened immune systems they are eligible to receive a third dose of Pfizer or Moderna four weeks after the second shot.
Regulators have not yet allowed booster vaccines for recipients of Moderna and Johnson & Johnson vaccines, but FDA panel scheduled to meet To weigh booster vaccines for adult recipients of Moderna and Johnson & Johnson vaccines.
The CDC said conditions that qualify a person for a booster shot include: hypertension and heart disease; diabetes or obesity; cancer or blood diseases; weakened immune system; chronic lung, kidney, or liver disease; dementia and some disabilities. Pregnant women and current and former smokers are also eligible.
The FDA has allowed boosters for workers whose jobs put them at risk of exposure to potentially infectious humans. The CDC says the group includes: emergency health workers; education workers; food and agricultural workers; manufacturing workers; correction workers; US Postal Service employees; public transport workers; grocery workers.
Not recommended. For now, Pfizer vaccine recipients are advised to receive the Pfizer booster vaccine, and Moderna and Johnson & Johnson recipients are advised to wait until these manufacturers’ booster doses are approved.
Yeah. The CDC says the Covid vaccine can be administered regardless of the timing of other vaccines, and many pharmacy sites allow people to schedule a flu shot at the same time as a booster dose.
most widely cited work The effect of natural immunity against the Delta variant comes from Israel.
The study found that infections occurring after vaccination were 13 times more likely than reinfection in unvaccinated persons, and symptomatic breakthrough infections were 27 times more likely than symptomatic reinfection.
But experts cautioned against inference from the results that natural immunity is superior to protection from vaccines. Bill Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health, noted that the vaccinated group included many more people with conditions that would weaken their immune responses, and more infections are expected.
The study also did not take into account people whose immune defenses may have been strengthened by a second exposure to the virus.
Experts said the vaccine is still the ideal choice for those lucky enough to survive Covid-19. provides massive increase antibody levels and almost insurmountable immune shield – perhaps against future variants.
An immunologist at Harvard Medical School, Dr. “They’re like rock stars in all variants,” said Duane Wesemann.
Dr. Color graphics from Wesemann final paper “It has helped convince patients recovering from Covid of the huge advantage that even a single dose can offer them,” he said.
Regardless of the evolving understanding of innate immunity, there is almost universal agreement among scientists at some point. For people who have never been infected, vaccines are much safer and much less of a gamble than Covid-19.
Many people who oppose vaccines cite low mortality rates from Covid-19 among young people. However, Dr. Iwasaki said that even seemingly mild cases of Covid-19 can cause long-term damage to the heart, kidneys and brain, or leave people feeling exhausted and unwell for weeks or months.
“No one should try to become immune through natural infection,” he said. “It’s just too dangerous.”
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