Natural immunity after Covid-19 could last at least 5 months

For the nearly 100 million people around the world who’ve been infected with the coronavirus, new science offers some comfort: Reinfections appear to be rare, and you may be protected from Covid-19 for at least five months.

The study, the largest of its kind, followed more than 20,000 health workers in the UK, regularly testing them for infection and antibodies. Between June and November, the researchers — from Public Health England (PHE) — found 44 potential reinfections out of the 6,614 participants who had tested positive for antibodies or had a previous positive PCR or antibody test when they joined the study. Meanwhile, of the 14,000-plus people who had tested negative for the virus at the start of the study, there were 409 new infections.

Only two of the 44 potential reinfections were designated “probable” and the rest were considered “possible,” “based on the amount of confirmatory evidence available,” according to the health agency. Fifteen people — or 34 percent — had symptoms.

So if all 44 reinfections are real, that translates to an 83 percent lower risk of reinfection compared to health workers who never had the virus. If only two are confirmed, that rate of protection goes up to 99 percent. Either way, it suggests natural immunity might provide a similar level of protection as the approved Covid-19 vaccines.

But as with the vaccines, it’s not yet clear how long immunity after an infection lasts. Antibodies may fade after five months or last much longer, something the researchers behind the ongoing study, which will run for a total of 12 months, plan to investigate.

“This [new] study does provide some comfort that naturally acquired antibodies are pretty effective in preventing reinfections,” Akiko Iwasaki, an immunobiologist at Yale University, told Vox. The findings also square with another paper on health workers, published in the New England Journal of Medicine in December: Researchers found people who had Covid-19 antibodies were better protected from the virus for six months than people who did not.

Iwasaki added, “You can also interpret these data to mean that protection against reinfection is not complete — especially for people who had Covid during the first wave, say in March-April 2020.”

People who had the virus may still be able to pass it on if reinfected

The good news for individuals who have had Covid-19 also comes with a warning about the risk they can still pose to other people. While antibodies might protect against a second case of Covid-19 in most people, “early evidence from the next stage of the study suggests that some of these individuals carry high levels of virus and could continue to transmit the virus to others,” PHE warned in its press release.

“We now know that most of those who have had the virus, and developed antibodies, are protected from reinfection, but this is not total,” Susan Hopkins, a senior medical adviser at PHE and the study lead, said in a statement, “and we do not yet know how long protection lasts.”

In other words, even if you’ve had Covid-19, while you’re unlikely to get really sick again anytime soon, you should still consider yourself a potential risk of spreading it to others if you catch the virus again and are asymptomatic. That means continuing to take precautions — like mask-wearing and social distancing, Iwasaki added. And it’s one reason why immunologists have said people who’ve already been infected with the virus should still plan to get the vaccine when their turn comes.

So there’s still a lot more to learn about immunity after Covid-19: How will the new coronavirus variants affect it? Lab data from South Africa, where the 501Y.V2 variant has been spreading, suggests it might be able to escape antibodies produced by prior infections in some people.

Who is most likely to have a strong immune response? We do have some evidence that different individuals mount different antibody responses after Covid-19 infections, but the PHE researchers found no statistically significant difference in rates of protection between people who reported symptoms and those who did not. It’s also possible factors like gender and disease severity influence the strength of a person’s immune response.

For now, though, the research suggests that survivors of the virus might just help us get to herd immunity faster — if their immunity lasts long enough. But given the virus has only been known to humans for a little over a year, it may take a while to authoritatively answer the question.

Click Here:

GPA back Antrim’s bid to play Ulster tie against Cavan at Corrigan Park

THE GPA HAVE backed Antrim’s bid to have their Ulster SFC opener against Cavan played at Corrigan Park next month. 

The Saffrons were drawn first out of the hat for the 23 April clash, handing them their first home championship game in nine years.

But an Ulster county board meeting last week saw delegates vote in favour of a Cavan motion to move the game out of the Belfast venue. Only Antrim, Tyrone and Derry voted against the motion.  

The Breffni County requested a change of venue due to Corrigan Park’s capacity of around 3,700. It is being used as Antrim’s home pitch while Casement Park remains closed for a development which has stalled for years.

A switch to a neutral venue in Armagh or Omagh was mooted it the game was moved.

Advertisement

The GPA are standing by Antrim’s case to retain home advantage and insist the game should take place at the original venue.

Click Here:

“So long as the ground can host the game safely which appears to be the case, it is only fair and proper that the game should go ahead in Corrigan Park as per the draw last November,” a GPA spokesperson told The42.

A final decision has not been made on the matter yet. Antrim are set to state their case at an Ulster CCC meeting on Wednesday night.

Meanwhile, Wexford GAA have pulled out of a planned event on Friday due to the GPA’s dispute with the GAA over travel expenses. 

Darragh Egan and a number of hurlers were due to give interviews.

“It has now been decided to postpone the media interview opportunity aspect of the event,” a statement said

“This is due to the current GPA request to players for non-engagement with the media.”

SEE SPORT
DIFFERENTLY

Get closer to the stories that matter with exclusive analysis, insight and debate in The42 Membership.

Become a Member

-Additional reporting by Sinéad Farrell

Ireland internationals Devin Toner and Lindsay Peat were our guests for The Front Row’s special live event, in partnership with Guinness, this week. The panel chats through Ireland’s championship chances ahead of the final round of Guinness Six Nations matches, and members of the Emerald Warriors – Ireland’s first LGBT+ inclusive rugby team – also join us to talk about breaking down barriers in rugby. Click here to subscribe or listen below:

Why scientists are more worried about the Covid-19 variant discovered in South Africa

Scientists are increasingly concerned about a rapidly spreading variant of the virus that causes Covid-19 that was first detected in South Africa. The variant may be more transmissible and could weaken protection from vaccines and prior infections.

There’s evidence from several small, and not-yet-peer-reviewed, studies that mutations in the South Africa variant — known as 501Y.V2 or B.1.351 and already present in at least 23 countries — may lead to reinfections in people who’ve been sick and still should have some immunity.

This 501Y.V2 variant is one of several seemingly more contagious variants of the new coronavirus currently in circulation. For instance, the B.1.1.7 variant that was first identified in the United Kingdom has already spread to several countries, and public health officials expect it will soon become dominant in the US.

But the variant first identified in South Africa is perhaps more alarming because of the prospect that the mutations it contains could limit the effectiveness of existing vaccines, one of the best tools we have for controlling the pandemic.

In their latest report, Moderna — the maker of one of two vaccines on the US market — found the British variant didn’t affect the levels of virus antibodies in the blood of people who had been vaccinated relative to prior variants, but the same wasn’t true for the South Africa strain. “These lower [antibody levels/titers] may suggest a potential risk of earlier waning of immunity to the new B.1.351 strains,” according to a January 25 press release.

The results of this and other recent studies are “a serious indication we have to look hard at how well vaccines might work,” Penny Moore, a virologist at the National Institute for Communicable Diseases in South Africa, told Vox. Taken together, they highlight the dangers of letting Covid-19 spread unchecked, and portend the challenges that lie ahead as the virus continues to evolve.

What the coronavirus variant discovered in South Africa might mean for Covid-19 vaccines

For the Moderna study, which is not yet peer-reviewed, researchers took the blood of eight people who had been vaccinated, as well as two monkeys, and tested it to see how the antibodies responded to the new variants compared with older versions of the virus. The UK variant did not seem to affect an individual’s antibody levels, but the South Africa variant did, reducing them by sixfold relative to older variants.

The company said that even the reduced antibody titers are high enough to still offer protection against the virus, meaning the vaccine will likely still prevent illness stemming from the 501Y.V2 variant. However, it points toward a path of mutations where the level of protection could erode faster than it would against older versions of the virus, increasing the risk of reinfection.

Moderna is now investigating how to reformulate its vaccine to better target the 501Y.V2 variant, while also studying whether an additional booster shot of its current vaccine could increase the levels of antibodies that can neutralize the variant.

The Moderna news comes after studies from other labs have arrived at similar conclusions. For a preprint paper (i.e., non-peer-reviewed) led by Rockefeller University scientists, researchers tested blood samples from 14 people who had received the Moderna vaccine and six who were immunized with the Pfizer/BioNTech vaccine. One particular mutation, named E484K, along with two others found in the South Africa variant, were associated with a “small but significant” drop in antibody activity, the researchers found.

Moore, of the National Institute for Communicable Diseases in South Africa, is the lead author of a new study on 501Y.V2, out as a preprint on BioRxiv. She and her team in South Africa took blood plasma samples from 44 people who had been infected with the coronavirus during the country’s first wave of infections last summer, and checked how their existing antibodies responded to 501Y.V2 as well as older variants.

The researchers sorted the plasma samples into categories — high and low antibody concentrations. In 21 cases — nearly half — the existing antibodies were powerless against the new variant when exposed in test tubes. This was especially true for plasma from people who had a mild previous infection, and lower levels of antibodies, to begin with.

These findings suggest immunity from previous versions of the virus might not help individuals fend off the new variant if they’re exposed, particularly if their prior case was mild or symptom-free.

For Fred Hutchinson Cancer Research Center scientist Trevor Bedford, who was not involved in the research, the study also came as a possible warning sign about the vaccines. As early as autumn this year, manufacturers may need to begin reformulating their shots to respond to the changes in the virus’s genetic code, he wrote on Twitter:

The specific mutation scientists are most worried about

The 501Y.V2 variant carries one mutation of particular concern, known as E484K. This change appears in the part of the virus, the spike protein, that fits into the receptor in human cells. The spike protein is also the major target for the currently available mRNA vaccines, from Pfizer/BioNTech and Moderna.

“This mutation sits right in the middle of a hotspot in the spike,” Moore said. And it’s become notorious among virologists for its ability to elude coronavirus antibodies.

Scientists have demonstrated how this might happen in other cell culture experiments. A new study, also in preprint form from South African researchers, took a similar approach to Moore’s — testing how antibodies from six convalescent plasma donors react to 501Y.V2. But this time they used live virus, considered “the gold standard for these experiments,” said study co-author Richard Lessells, a University of KwaZulu-Natal infectious disease specialist. And their findings pointed in the same direction: 501Y.V2 can — at least in the lab — escape the antibody response elicited from a prior infection, and the E484K mutation “has the clearest association with immune escape.”

In another recently published BioRxiv preprint, researchers in Washington state tracked how mutations altered the effectiveness of the antibody response in convalescent plasma of 11 people — and also found E484K had particularly potent antibody evasion capabilities.

Other variants of concern also carry the E484K mutation, including one first identified in Manaus, Brazil, known as P.1. And one case study suggests reinfection in some people might be possible when they’re exposed to the new variant.

In a preprint, researchers in Brazil documented the case of a 45-year-old Covid-19 patient with no comorbidities, who, months after her first bout with the illness, was reinfected with the new variant. The patient experienced more severe illness the second time around. While it’s limited evidence, it “might have major implications for public health policies, surveillance and immunization strategies,” the authors wrote.

The study’s broader context is also concerning: After up to three-quarters of the population in Manaus, Brazil, was estimated to be infected with the virus during a spring surge, cases are piling up again and hospitals are filling up. Researchers suspect reinfections with the new variant could be a driver.

“The news is not all grim”

But “the news is not all grim,” said University of Utah evolutionary virologist Stephen Goldstein. The Rockefeller University preprint found antibodies from the vaccine may be more potent than antibodies from a previous infection. And the antibodies induced by the vaccines “are so high to start with that the serum was still extremely potent against the mutant.”

To fully understand the threat the mutations pose to vaccines, we’ll need clinical trials involving vaccinated people, Moore said. “These studies flag a problem,” she added, “but how that translates to real life, we can’t tell.”

Click Here:

There’s also huge variation in immune responses among people, Goldstein said. In the Washington paper, the researchers found “extensive person-to-person variation” in how the mutations affected an individual’s antibody response.

“The bottom line there is some reason for concern about reduced efficacy, but efficacy will not fall off a cliff,” Goldstein said. “The vaccines are incredibly potent. … If [they go] from 95% [efficacy] to 85% or even a little lower, we are still in great shape.” That’s why researchers and public health officials are heavily advocating for everyone to be vaccinated as quickly as possible.

Even so, Moore cautioned: “From an immune escape point of view, the variants first detected in Brazil and South Africa are more of a concern, but this is just the beginning. It’s our first indication that this virus can and does change.”

It’s possible that as we learn more, even the E484K mutation won’t turn out to undermine the vaccines. But there may be other changes to the virus lurking out there or evolving that will escape even vaccine-induced antibodies. “So many people now are infected that this is an arms race — the virus is now given every opportunity to mutate,” Moore said, “so it can take those steps on the pathway to immune escape more easily.”

How random people have managed to get leftover coronavirus vaccines

Since December, a handful of fortunate end-of-day shoppers have received coveted doses of the coronavirus vaccine by simply being in the right place at the right time. That place, during a pandemic, could be a Safeway or a Walgreens. Some of these recipients are young and healthy adults, and have likened their surprise immunization to winning the lottery.

As the country embarks on a decentralized Covid-19 vaccine rollout program, grocery stores and pharmacies are at the forefront of inoculating local residents and, in some cases, issuing leftover doses to whoever might be available. Some social media users have joked about hanging around pharmacies near closing time in the hope of receiving a leftover vaccine dose, instead of allowing it to go to waste.

Los Angeles County, for example, has no official standby line for the coronavirus vaccine, but hundreds of “vaccine chasers” — young people, entire families, and even seniors unable to secure an appointment — have flocked to sites countywide in the hopes of receiving an expiring shot. Getting a vaccine depends on who you know and access to local news: The Los Angeles Times reported that those waiting outside clinics “heard about the opportunity through word of mouth in their social and professional networks,” and some hailed from wealthier neighborhoods.

State and local jurisdictions are being recommended by the Centers for Disease Control and Prevention to issue their first vaccine doses to health care personnel, residents of long-term care facilities, and, more recently, adults over 65 and anyone with underlying medical conditions. These are only recommendations, though. Governors and individual vaccination sites are in charge of implementing their own vaccine prioritization plans. As coronavirus cases rise, state officials are amending their vaccine guidelines to include a larger population of people.

The US is lagging behind its projected vaccination goal of 20 million people by the end of 2020; only about 9 million people have received the vaccine’s first dose as of January 11. The two available vaccines, made by Moderna and Pfizer/BioNTech, have to be injected within hours after the doses are thawed from subzero storage temperatures, which complicates their distribution. Health and state officials have begun urging medical providers to consider vaccinating lower-priority groups to minimize vaccine wastage. As a result of these logistical hiccups, a small group of healthy, low-priority people has been administered the vaccine as a measure of last resort.

A number of these random immunizations (that have been publicly documented, at least) have occurred in Washington, DC, where local health officials have encouraged pharmacists to adopt a zero-waste policy. A DC-based law student posted a viral TikTok of his Moderna shot, which he was offered while grocery shopping at a Giant Food. A DC-based reporter was inoculated at Safeway after hearing an in-store announcement that its pharmacy had extra doses left. A DC couple was able to get on a Safeway pharmacy waitlist to receive end-of-day vaccines for when priority patients fail to show up for one.

There have been a few instances reported elsewhere as well: A Louisville couple made news for receiving a Christmas Eve vaccine at a local Walgreens. “[A friend] called us, and we ran right up. It was pure luck,” the recipient told the Courier Journal. The pharmacy later said it sought to prioritize its excess doses to first responders, Walgreens staff, and senior residents as the news garnered attention.

Sudden time-sensitive incidents such as a malfunctioning hospital freezer in Ukiah, California, have forced providers to make rapid distribution decisions with little forethought. But there are also instances of those looking to jump the line if providers are disorganized. The Los Angeles Times reported that at one South LA vaccination site in early January, about 100 people received vaccines without being asked to show proof that they worked in the health care industry.

These stories of circumstantial — even chaotic — vaccinations might provide a semblance of hope for those who fall further down the priority list. According to Business Insider, pharmacies and grocery stores in the DC metro area are already fielding “tons of calls” from interested recipients eager to get on a vaccine waitlist. These last-minute lists in DC, however, have quickly filled up via word of mouth. A pharmacy manager in Pennsylvania told the local Fox News station that it only takes names of those eligible under the state’s 1A categorization, which includes health care workers and residents of long-term care facilities, for its “do not waste” list. (The Food and Drug Administration and the federal government have yet to issue guidelines on who these extra doses should go to.)

These waitlists and random occurrences aren’t necessarily cause for optimism, though, especially as the vaccination timeline for most Americans remains unclear and varies from state to state.

“There has been outsized media and social media attention to the number of people this has happened to,” Josh Michaud, associate director for global health policy of the Kaiser Family Foundation, told Vox. “It’s a good approach to not waste vaccine doses at the end of the day … but in the grand scheme of things, it’s going to be a marginal contribution to vaccinations. The bulk of vaccinations being done at pharmacies are for those who fit into the prioritization groups and made appointments.”

It’s possible that vaccine providers might no longer need to resort to waitlists or last-minute immunizations, Michaud said, since the federal government has revised their vaccine recommendations: “We’re seeing more states moving in that direction, so the phenomenon of finding a random person might become less common, simply because there will be more people who fit into those higher-priority categories.”

The public desperation for a last-minute shot signifies a top-down failure of the federal government: Officials have largely ignored expert warnings of the potential for logistical hindrances, and there is no cohesive communication campaign to inform Americans when they’re available for a shot. Even as providers do their best to minimize vaccine waste, the disorganized rollout makes it harder for higher-risk Americans to receive the first vaccine dose. This approach “undercut[s] the needs-based approach to those who are savvy and to those who realize what’s going on,” Arthur Caplan of the Division of Medical Ethics at New York University told Business Insider.

The US population has a long way to go to reach herd immunity — which may require 70-85 percent of the population vaccinated — in order for normal life to resume. Officials have maintained that the more people who get vaccinated, the better, and so the general interest toward these random store vaccinations is a good thing. But most members of the public won’t be able to skip the wait, unlike the lucky few on social media, no matter how often they stop by their local pharmacy.

Click Here:

Biden now promises 200 million vaccine shots in 100 days. The US is already on track for that.

President Joe Biden on Thursday set a new goal for Covid-19 vaccines in the US: 200 million shots in his first 100 days in office. That’s up from Biden’s original goal of 100 million in 100 days. “I know it is ambitious — twice our original goal,” Biden said.

But the goal of 200 million shots in 100 days is really not that ambitious; it’s achievable if absolutely nothing changes with America’s current vaccine rollout.

That’s a testament to how much America’s vaccine campaign has improved since Biden took office. Before Inauguration Day, the country administered less than 1 million shots a day. Today, the US is at 2.5 million shots a day, on average.

At the current rate, the country could hit Biden’s goal of 200 million shots in 100 days — hitting the goal as soon as April 28, a couple days before Biden’s 100th day in office.

Things stand to improve beyond the current rate. As vaccine manufacturers ramp up production, they’ve already made deals with the federal government to deliver enough vaccines for every adult in the summer. At the very least, that should address questions about the supply of vaccines, though not about distribution or willingness to take them.