When it comes to acquired immunity against COVID-19, also known as natural immunity, scientists agree that people looking for protection against the coronavirus certainly shouldn’t be running out to get intentionally infected.
Yet a number of recent studies — some that suggest prior COVID-19 infection can provide significant immunity and others that suggest vaccination is much more effective — have triggered discussion within the scientific community about the strength of natural immunity.
Many scientists say vaccination is still essential for those who have contracted COVID-19, and that the combination of previous infection and vaccination may actually offer the best level of protection.
Monica Gandhi, a professor of medicine and infectious diseases at the University of California, San Francisco’s School of Medicine, is among the experts who believe one dose of vaccine after prior infection offers the best protection. She says the extent of immunity after infection is a very legitimate scientific debate.
“And the problem with this current debate,” she said, “is that to ignore natural immunity and say it isn’t a thing is leading to a lot of distrust of public health officials.”
‘Strongly disagree’ natural immunity better than vaccination
What goes beyond the bounds of legitimate debate, say many scientists, is the idea being suggested by some other scientists that acquired immunity from infection should be considered as effective or better than vaccination.
“I strongly disagree with that assessment,” said Theodora Hatziioannou, a virologist at the Rockefeller University in New York City.
Acquired immunity is the protection that a person develops to a disease after being infected. In Canada and the U.S., a previous infection is not counted as part of an individual’s vaccination status. A person who has had COVID-19 still requires two doses of an approved vaccine to be considered fully vaccinated.
But citizens in many European countries who have had the illness and received a single dose of vaccine are considered fully vaccinated. And in Israel, a person who has recovered from COVID-19 is considered fully vaccinated without having received a shot of vaccine.
From a purely medical perspective, if someone has had a prior infection, they of course should be able to mount an immune response that can protect them for a certain amount of time, said Matthew Miller, an associate professor in the Michael G. DeGroote Institute for Infectious Diseases at McMaster University in Hamilton.
However, most of the studies that have compared the immunity resulting from infection with that of vaccination have found that two doses of vaccine, especially mRNA vaccines, provide higher levels of antibodies than a prior infection, he said.
Dawn Bowdish, Canada Research Chair in Aging and Immunity and a professor at McMaster University, said she’s been working with people who were hospitalized with COVID-19 and found they “tend to have pretty robust immune responses because they had quite a bit of time with the virus.”
She said immunity from previous infection may be enough for “some of the people, some of the time,” but it’s “quite proportionate to how sick you got, and there’s a lot of variability in people who had low-level infections.”
‘The durability of the response’
For example, Bowdish recently had someone give blood who had previously been infected with COVID-19 but only with very mild symptoms.
“We struggled to find any evidence that she had any immunity whatsoever,” Bowdish said of the test results.
When asked about natural immunity on CNN last month, Dr. Anthony Fauci, the top infectious disease expert in the U.S, said he couldn’t provide a firm answer on the subject.
“That’s something that we’re going to have to discuss regarding the durability of the response,” said Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID).
It’s an issue many people opposed to vaccines have seized upon, particularly the comments of some scientists who have gone so far as to advocate natural immunity as equal to or perhaps better than double-dose vaccination.
The problem with that, says Hatziioannou, and what many scientists will point out, is that the level of natural immunity is quite varied between different people, and that protection varies depending on the severity of their prior illness.
Based on her own data, she estimates very few of those previously infected with COVID-19, around 10 per cent, mount a “really significantly high neutralizing antibody response.”
The rest, she said, develop a medium to low response, with the majority pretty low.
“It appears the more sick you are, the higher the levels of your antibodies, generally speaking. But overall, the majority of infections are either asymptomatic or very, very mild to moderate. So I would not expect the majority of these people will have really high neutralizing antibodies.”
Impact on variants
As well, the particular coronavirus variant that infected the individual will inevitably have some degree of impact on how well it protects them from infection with a different variant, Miller said, which adds another layer of complexity to the issue.
“I think that the scientific issue of whether symptomatic infection can protect you from a future infection — I think that’s clear,” he said. “Is it clear exactly how well and to what extent and for what period of time? No, it’s not.”
Other scientists, meanwhile, suggest the case is pretty clear that natural immunity may provide more protection than previously thought.
Matthew Memoli, director of NIAID’s Laboratory of Infectious Diseases Clinical Studies Unit, told the BMJ, a U.K.-based peer-reviewed medical journal, that there probably isn’t much difference between natural immunity and vaccination in terms of resistance to the spike protein — a crucial feature on the surface of the coronavirus that allows it to gain access to our cells.
Vaccines, he said, are focused only on that tiny portion of immunity that can be induced by neutralizing the spike, while someone who has had COVID-19 was exposed to the whole virus, “which would likely offer a broader based immunity” that would be more protective against variants.
Experts make case for natural immunity
Jeffrey D. Klausner, a professor of population and public health sciences at the University of Southern California published a study that suggests there is “consistent epidemiological evidence” that prior infection provides “substantial immunity” to repeat infection and provides similar protection when compared to vaccination.
Marty Makary, a professor at the Johns Hopkins School of Medicine and Bloomberg School of Public Health in Baltimore, Md., has been very vocal in making his case that policy-makers need to consider natural immunity as equal to or better than vaccination.
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In a Washington Post column last month, Makary, a surgical oncologist, wrote that for far too long, public health officials have dismissed natural immunity as unreliable protection against COVID-19 — “a contention that is being rapidly debunked by science.”
Makary pointed to some recent studies, including one in Israel that found people who were double vaccinated were six times more likely to get infected with the delta variant compared to those who had been previously infected with COVID-19 but not vaccinated.
But Fauci, during his appearance on CNN last month, said the Israeli study did not address the durability of immunity from infection compared to that which results from vaccination.
“So you may be protected, but you may not be protected for an indefinite period of time,” he said.
Meanwhile, other studies have suggested limits to natural immunity. A study from the U.S. Centers for Disease Control and Prevention published last month found unvaccinated people previously infected with COVID-19 were twice as likely to be reinfected than those who were fully vaccinated after previously contracting the virus.
Still, the efficacy of natural immunity could have potential policy implications, particularly in countries where vaccines are in short supply.
And researchers are finding that the combination of prior COVID-19 infection and vaccination, so-called hybrid immunity, may offer the best protection.
Bowdish said McMaster University is currently conducting a study in long-term care with 60 COVID-19 survivors.
“And we definitely found that after they got their vaccine, they seem to be the ones that are having really robust, long immune responses,” she said.
Hatziioannou agreed that the research suggests people who were previously infected, even if their initial immune responses were not great, that once they get vaccinated, even with just with a single dose, their immunity “became remarkable.”
“It really is really great immunity,” she said. “It makes no sense to say that immunity from infections is sufficient.”
With Covid vaccination & booster shots, should we worry about omicron? What is known and still unknown – Economic Times
What is the omicron variant?
First identified in Botswana and South Africa, this new iteration of the coronavirus has prompted concern among scientists and public health officials because of an unusually high number of mutations that have the potential to make the virus more transmissible and less susceptible to existing vaccines.
The World Health Organization has called omicron a “variant of concern” and Monday warned that the global risks posed by it were “very high,” despite what officials described as a multitude of uncertainties. Cases have been identified in 20 countries so far, including Britain, Italy, Belgium and the Netherlands. Although omicron has not yet been detected in the United States, experts say it is only a matter of time before the variant shows up.
Should we be worried?
Omicron’s discovery has prompted considerable panic, with a number of countries banning flights from southern Africa, or — like Israel, Japan and Morocco — barring entry of foreign travelers altogether.
But public health experts have urged caution, noting that there is as yet no firm evidence that omicron is more dangerous than previous variants like delta, which quickly overtook its predecessors in the United States and other countries.
Although delta turned out to be much more transmissible than prior variants — and there is some data suggesting it can cause more severe illness in the unvaccinated — there is little evidence it is more lethal or capable of outsmarting vaccines.
Much remains unknown about omicron, including whether it is more transmissible and capable of causing more serious illness. There is some evidence the variant can reinfect people more readily.
There are early signs that omicron may cause only mild illness. But that observation was based mainly on South Africa’s cases among young people, who are less likely overall to become severely ill from COVID.
Dr. Angelique Coetzee, who chairs the South African Medical Association, said that the nation’s hospitals were not overwhelmed by patients infected with the new variant, and most of those hospitalized were not fully immunized. Moreover, most patients she had seen did not lose their sense of taste and smell, and had only a slight cough.
On Tuesday, Regeneron said its COVID antibody treatment might be less effective against omicron, an indication that the popular and widely beneficial monoclonal antibody drugs may need to be updated if the new variant spreads aggressively.
That said, omicron’s emergence is so recent that it may be a while before experts know whether it is more pathogenic. COVID hospitalizations lag new infections by two weeks or more.
Scientists expect to learn much more in the coming weeks. At the moment, they say there is no reason to believe omicron is impervious to existing vaccines, although they may turn out to be less protective to some unknown degree.
There’s another reason to remain calm: Vaccine makers have expressed confidence they can tweak existing formulations to make the shots more effective against new variants.
Also reassuring: Omicron’s distinctive mutations make it easy to quickly identify with a nasal swab and lab test.
Why are scientists so concerned about omicron?
As the coronavirus replicates inside people, new mutations constantly arise. Most provide the virus with no new advantage, but sometimes mutations can give the pathogen a leg up by allowing it spread more readily among its human hosts or dodge the body’s immune response.
Researchers in South Africa sounded the alarm because they found more than 30 mutations in the spike protein, a component on the surface of the variant that allows it to bind to human cells and gain entry to the body. Some of the samples from Botswana shared about 50 mutations throughout the virus not previously found in combination.
The spike protein is the chief target of antibodies that the immune system produces to fight a COVID-19 infection. Having so many mutations raises concerns that omicron’s spike might be able to somewhat evade antibodies produced by either previous infection or vaccination.
Those mutations also raise the prospect that the variant will reduce the efficacy of monoclonal antibody treatments — a fear partly confirmed Tuesday with Regeneron’s announcement.
Still, it is worth remembering the fate of earlier variants that stirred concern: Beta and mu, for example, evolved the ability to partially evade the body’s immune defenses, but they never became a serious threat to the world because they proved to be poor at transmitting.
What about vaccines?
Vaccines are expected to provide some protection against omicron because they stimulate not only antibodies but also other immune cells that attack virus-infected cells. Mutations to the spike protein do not blunt that response, which most experts believe is instrumental in preventing serious illness and death.
Citing the potential for waning immunity six months or more after vaccination, some health experts are promoting booster shots to increase antibody levels.
The nation’s top infectious disease expert, Dr. Anthony Fauci, has urged people to get a booster shot, which he said would most likely provide additional protection against severe disease. “We’ve said it over and over again and it deserves repeating. If you’re not vaccinated, get vaccinated, get boosted if you are vaccinated, continue to use the mitigation methods, namely masks, avoiding crowds and poorly ventilated spaces,” he said Tuesday.
Moderna, Pfizer-BioNTech and Johnson & Johnson, makers of vaccines approved for use in the United States, and AstraZeneca, which is widely used in Europe, have all said they were studying omicron and expressed confidence in their ability to tailor their formulations to target the variant.
Why is it called omicron?
When the WHO began to name emerging variants of the coronavirus, they turned to the Greek alphabet — alpha, beta, gamma, delta and so on — to make them easier to describe. The first “variant of concern,” alpha, was identified in Britain in late 2020, soon followed by beta in South Africa.
But veterans of American sorority and fraternity life might have noticed the system has skipped the next two letters in the alphabetical order: nu and xi.
Officials thought nu would be too easily confused with “new,” but the next letter, xi, is a bit more complicated. WHO officials said it was a common last name, and therefore potentially confusing. Some noted that it is also the name of China’s top leader, Xi Jinping.
A spokesman for the WHO said organization’s policy was designed to avoid “causing offense to any cultural, social, national, regional, professional, or ethnic groups.”
Next in line? Omicron.
I’m fully vaccinated — I’ve even had my booster. So why should I care about omicron?
Like delta, which was first identified in India, the rise of yet another worrisome variant in the developing world points to a more fundamental problem facing the global community more than a year and a half into the pandemic.
The hoarding of vaccines by wealthy countries while poorer nations struggle to obtain them provides more opportunities for SARS CoV-2 to replicate and mutate among the unvaccinated. More mutations mean there are more chances for the virus to become more infectious, immune-resistant or lethal.
And as the rapid spread of delta showed, a dangerous new variant is unlikely to remain in one place for very long.
The risks extend beyond public health. The resulting economic devastation from a new variant can hit affluent countries nearly as hard as those in the developing world. One academic study estimated trillions of dollars in economic loss to wealthy countries when residents of poorer countries remain largely unvaccinated.
World AIDS Day— A conversation with Dr. Jean-Pierre Routy – McGill University Health Centre
An update on HIV research and care, nearly two years into the COVID-19 pandemic
On the occasion of World AIDS Day, we spoke with Dr. Jean-Pierre Routy, Clinical Director of the Chronic Viral Illness Service at the MUHC, Senior Scientist in the Infectious Diseases and Immunity in Global Health Program at the Research Institute of the MUHC and Director of the FRQS AIDS and Infectious Diseases Network. Dr. Routy is also the co-chair of the International AIDS Conference 2022, which will be held from July 29 to August 2, 2022, in Montreal.
To mark World AIDS Day, you have organized an event to pay tribute to the pioneers of Quebec’s HIV-AIDS response.
Yes. We want to pay tribute to the doctors and field workers who initiated the fight against AIDS in Quebec 40 years ago, to talk about the progress that was made and commemorate HIV victims. Hosted by Yanick Villedieu, science journalist at Radio-Canada, the evening will include testimonies from some of the pioneers, as well as literary reading selected by author Catherine Mavrikakis, and read by Jean Marchand.
You talk about progress… What is the status of HIV/AIDS research today?
After 40 years of research, there is still no effective HIV vaccine. The challenge is to develop an HIV vaccine that does not create inflammation, and so far, this has not been successful.
In fact, the “superpower” of HIV is that it infects cells when they enter an inflammatory phase to fight an enemy. The cells “cry wolf” and the wolf—in this case HIV—infects them more easily because it knows where they are. This mode of action is unique to HIV, which infects CD4 lymphocytes that are central to the coordination of the immune response. Moreover, we know that the colon has more CD4 cells and therefore more HIV, because the cells are more inflamed.
For this reason, recent scientific developments about the gut microbiome is of particular interest to HIV research. Every day, immune cells in the digestive system must stop microbes while allowing nutrient absorption. Alteration of these immune cells contributes to an inflammatory syndrome related to a greater passage of microbial particles into the blood. This regulatory process could be modified by drugs that act in the digestive tract, as suggested in a recent study that we published in PNAS.
On the other hand, where we have failed with vaccines, we have prevailed with antiretroviral drugs, which are now incredibly powerful. These treatments make it possible to achieve and maintain an undetectable viral load and thus to stop sexual transmission—hence the equation undetectable = untransmissible (u=u). People living with HIV, and who follow treatment, no longer transmit the virus. For people who engage in risky behaviours, taking daily medication protects them from acquiring the virus, but not from other sexually transmitted infections.
In both types of treatment, people must take daily medication, which is sometimes difficult. As a result, what is being developed now is a long-acting injectable drug that could protect an individual for six months. A two-month version is already on the market in Canada; its development was delayed by the COVID-19 pandemic. The 6-month version should have a greater impact.
How has the COVID-19 pandemic affected research and care?
Like other diseases, AIDS has been overshadowed by COVID-19. A lot of research money was invested in COVID-19. In many cases, the same doctors who were working on HIV started working on SARS-Cov-2. So obviously, research has slowed down a bit.
On the care and prevention side, the pandemic has affected the follow-up of some patients. Approximately 10 per cent of patients stopped their treatment or interrupted their medical follow-up, which led, for some, to hospitalizations. Some patients lost their jobs and stopped taking their medication due to a drop in income. There has also been a decrease in the number of tests performed, following temporary closure of testing centres. We do not have precise figures yet, but this has certainly had an impact on health and the transmission of HIV.
What are your hopes for the future?
COVID-19 has had dramatic effects around the world but remains benign in the majority of cases. HIV, on the other hand, affects people for life and remains a major source of stigma.
It is important to re-engage and follow the science—the theme of the upcoming International AIDS Conference 2022, to be held in Montreal next summer. We need to re-engage patients, prevention, vaccine research, and the pharmaceutical industry. All of this must be based on science, and that involves fighting anti-immigrant, anti-LGBTQ2+ rhetoric. When it comes to communicable diseases, we must never let our guard down.
How to talk to children about getting their vaccine: U of T's Jean Wilson shares advice – News@UofT
With kids age five to 11 now eligible for COVID-19 vaccines in Ontario, Jean Wilson of the University of Toronto’s Lawrence S. Bloomberg Faculty of Nursing has some tips to help lessen children’s fear of needles – and ease parents’ anxiety, too.
“Well before their child’s first scheduled vaccinations, I start by talking to parents about the importance of vaccinations,” says Wilson, an assistant professor, teaching stream and nurse practitioner at St. Michael’s Hospital. “Every parent wants to do what is best for their child, so the more information they have the more comfortable they will be with their decision.”
Wilson was part of a panel of experts from the Leslie Dan Faculty of Pharmacy, Faculty of Nursing, Centre for Addiction and Mental Health and Niagara Region Public Health who shared insights last week in a talk titled “How to Talk to Your Children About Vaccines.” The event aimed to provide parents and caregivers with helpful information to prepare their kids for vaccines including Health Canada-approved COVID-19 shots.
The line-up of speakers also featured Anna Taddio, a pharmacy professor who developed the CARD system to reduce pain and fear of needles among kids. CARD (Comfort, Ask, Relaxation and Distract) is an evidence-based system that invites students to choose a coping strategy to improve the vaccination experience (such as playing with their phones to distract them from getting a shot.)
Wilson, who has worked for the Public Health Agency of Canada on communicable disease outbreak management, discussed how the mRNA vaccines work and the importance of vaccination.
She recently spoke with U of T’s Rebecca Biason about how to help kids cope with needle phobia and how nurse practitioners can reduce vaccine hesitancy.
How can parents help kids feel comfortable with getting vaccinated?
One of the first things I ask parents is whether they are afraid of needles. If the parent is anxious, the child can often pick up on this energy. I suggest that parents try to get as much information as possible about the decision they are making, appear calm and normalize the situation when discussing vaccines and needles with their children. Being honest with their child is very important. It is important to say, “We are going to get your needle today, it will pinch for a few seconds, but right after we will go to the store [or some other positive experience for the child].” Making it a part of a normal day helps the child feel more at ease and doesn’t make the vaccine experience feel so momentous.
This is also where parents and practitioners can utilize Professor Anna Taddio’s Comfort, Ask, Relax, Distract (CARD) system. I will often ask parents to help the child feel comfortable. Maybe that’s lying down or maybe that’s sitting on the parent’s lap. For babies who are breastfeeding, I would encourage mom to breastfeed before and after the vaccine as it has been shown to comfort, distract and manage pain.
Parents and practitioners can adapt the CARD system depending on the developmental age of the child as well. For older kids or teenagers, we might suggest they put headphones on and listen to their favourite song.
In my practice, I have liquid bubbles on hand to blow after a vaccine that works really well for children six months and up. Sometimes, we clap hands and/or sing songs after the vaccination – all of which can distract the child from any pain they might feel. I might also ask the child to wiggle their toes on the count of three before giving the shot. This distracts the brain/pain pathway physiologically, and can also help minimize pain.
The CARD system is an important part of the toolbox and I encourage practitioners and parents to try and utilize it to help make the vaccination process for their children more comfortable, less anxiety provoking and empowering for parents too.
How are the common misconceptions about the vaccine that you have encountered?
I get questions about the vaccine being rushed to market and whether it is safe. While the pandemic has required a more expedited process to help us get a vaccine, I discuss with parents that we have a comprehensive and robust vaccine approval process in Canada, and this continues even with the COVID-19 vaccines. While the vaccine manufacturer information and research data is coming in on an ongoing basis, experts at Health Canada, the Public Health Agency of Canada and provinces have been working hard to review the information in detail, strictly adhering to all the safety checks and balances that have always been in place to ensure that vaccines used in Canada are effective and safe.
The Pfizer-BioNTech COVID-19 vaccine approved for use in children by Health Canada shows side-effects that are very mild and similar to what we have seen with children 12 years and older receiving the vaccine. There were no severe allergic reactions or complications (such as myocarditis/pericarditis, multi-system inflammatory syndrome or deaths). This safety profile has also been seen in the 2.5 million children vaccinated in the United States where the vaccine was approved earlier this fall.
Another question I often get is does the mRNA change our DNA and/or interfere with fertility? The answer is no.
I tell parents how the vaccine works in the body. The mRNA in the vaccine is a small blueprint for only the spikes on the outside of the virus that causes COVID-19. When the person gets the vaccine, the mRNA goes into the cell but never goes into the nucleus where our DNA is stored. The mRNA stays in the cell liquid outside the nucleus and that is where the mRNA is read, processed and protein pieces move to the outside of the cell surface, so the person’s immune system starts to create protection called antibodies against COVID-19. The body destroys all the vaccine mRNA shortly after it is read. Once antibodies are created, if the person is ever exposed or infected with the actual COVID-19 virus, their immune system identifies the spikes and immediately starts to attack the virus and stops or minimizes the infection.
Why should parents vaccinate their children against COVID-19?
Parents want to make the best decisions for their children. This is where the “Ask” part of the CARD system comes into play. A parent’s hesitancy around vaccinations can be the result of a variety of things including their own experiences with vaccinations, mistrust of the health-care system as a whole or misinformation they have gleaned from the internet. Providers can often alleviate hesitancy by providing trusted information and online resources.
I often get questions about why children should get vaccines if they don’t get symptoms or only a very mild case of COVID-19. While this is true, unfortunately in the third and fourth COVID waves, we have seen more children becoming sick with COVID. While the risk of severe illness and hospitalization is less for children compared with adults, this still occurs and can happen to children who were otherwise healthy.
I discuss with parents the possible complications of COVID. Some children might develop multi-system inflammatory syndrome and require hospitalization. We also know from newly published research about children with COVID, regardless of the severity, can develop complications such as long COVID, a condition in which COVID symptoms remain with the child for months after the initial illness. We are still learning more about this.
Finally, I talk to parents about the social and psychological aspects of the pandemic on children. The faster we get as many people protected from this virus, the sooner we can get back to normal life for both parents and children. We know that children have been impacted by the change in routine, social isolation, disruption to school and extracurricular activities and the stressful impact COVID has had on their parents, family and friends. Part of the vaccination process is to assist in making the child’s environment stable again for their well-being. I encourage parents who are talking to their children about the COVID vaccine to explain that this will help us get back to activities they love such as going to school, sports activities, sleepovers, visiting grandparents and other elderly loved ones and taking family trips.
When I sit with people who have been hesitant, it takes such a short amount of time to answer their questions in a non-judgmental, respectful way. It doesn’t take much to reassure them. As practitioners, we must be able to take that time to listen and answer questions knowledgably and most of the time, parents are reassured and feel better informed to make this important decision for themselves and their children. Nurses are a highly trusted profession and viewed as being knowledgeable. Using that gift and skill is vital to helping people make evidence-based decisions.
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