Category: COVID

Should Unvaccinated-by-choice COVID Patients Get Less Priority?

Credit: ATS

A new opinion piece provides an exhaustive examination of the ethics of using hospital resources on unvaccinated-by-choice COVID patients with pneumonia, versus patients with other serious but slower illnesses.

In his article published online in the Annals of the American Thoracic Society, William F. Parker, MD, PhD, looked at cases in which hospitals delayed time-sensitive and medically necessary procedures for vaccinated adults when they were overwhelmed with unvaccinated patients who had severe, life-threatening COVID pneumonia and suggested an ethical framework for triaging these patients.

“These vaccinated patients are directly harmed when hospitals use all their resources to care for the many unvaccinated patients with COVID,” he wrote.  “For example, delaying breast cancer surgery by just four weeks increases the relative risk of death from the disease by 8%.”

Dr Parker argues for a contingency care standard prioritising emergency life-support, regardless of vaccination status, in order to save the most lives.  “Simply rejecting the use of vaccination in prioritisation of medical resources without analysis ignores the very real tradeoffs at play during a pandemic.  The pain and suffering of the vaccinated from deferred medical care require a deeper defense of caring for the unvaccinated.”

Eliminating double standards
He stated: “Even though the vast majority of patients who develop life-threatening COVID pneumonia are unvaccinated, hospitals still have ethical obligations to expand capacity and focus operations on caring for them—even if it means making vaccinated patients wait for important but less urgent care like cancer and heart surgeries.”

“If tertiary care centers turn inward and stop taking transfers of COVID patients from overwhelmed community hospitals, this will result in de facto triage in favor of lower benefit care and cause systematic harm to both the vaccinated and unvaccinated in vulnerable communities,” he adds.  “Hospitals must justify their nonprofit status by accepting transfers and prioritizing life-saving care during a pandemic surge.”

He cited the example of a surge in Los Angeles, when the public health department had to issue an order forcing elite hospitals to stop doing financially lucrative elective procedures and accept patient transfers from community hospitals with ICUs overwhelmed by COVID.

Reciprocity and proportionality
The principle of reciprocity supports a possible tiebreaker role for vaccination status when two patients have equivalent survival benefit from a scarce health care resource. However, a universal exclusion of the unvaccinated from life support during a pandemic surge fails the test of proportionality for reciprocity, according to Dr Parker.

Reciprocity is rewarding one positive action with another. One example of this principle is giving vaccinated people access to sporting or entertainment events that are off limits to the unvaccinated (even if negative for COVID). Proportionality is the principle that ‘payback’ should be proportional to the magnitude of the act.  For example, living kidney donors get moved way up the waitlist- the equivalent of four years of waiting time on dialysis.  This satisfies the proportionality principle.

Dr Parker points out that while the increased relative risk of death of 8% from deferring breast cancer surgery is awful, the absolute increase in risk is only one per 100, and perhaps only one per 200 for a two-week deferral.
“After the surge is over, the hospital can catch up on deferred elective surgeries,” he wrote. “The harm from a coronary artery bypass or cancer surgery delayed two weeks is real, but tiny in comparison to certain death from denying life support for respiratory failure.”

He concluded that: “There is a defensible role for vaccination status in triage as a limited tiebreaker, not as a categorical exclusion, but only in the context of a well-defined and transparent triage algorithm.  Despite the enormous financial pressure to do otherwise, elite academic centres are obligated to prioritise life support for emergency conditions to save as many lives as possible during COVID surges.”    

Source: EurekAlert!

Vaccine Mandate Battle Looms as Omicron Cases Surge

Photo by Mat Napo on Unsplash

As President Cyril Ramaphosa warns that the long-expected fourth wave is upon the country, a legal battle against mandatory vaccination is brewing even as Omicron rates create an unprecedented surge, likely driven through re-infections.  

Omicron, detected by South African scientists only two weeks ago, is now dominating in most provinces. However, he stressed that the country had been prepared for a fourth wave, having long been predicted by modellers. He reiterated the call for more vaccinations and to observe social distancing as much as possible over the festive season.

Vaccine mandates are now on the cards, which are expected to be introduced in early 2022. Civil rights groups including Afriforum and Sakeliga have threatened legal action if the government moves ahead on its plans to introduce vaccine mandates.

Afriforum called vaccine mandates a violation of personal freedoms, and cited Ramaphosa’s statement February this year saying that nobody in the country would be forced to take a vaccination.

As of Monday evening, reported test positivity rate now stands at 26.4%, which is well above the 10% ‘level of concern’ which had been reached a week ago.. In the third wave, it took about a month to go from this level to 25%

At this stage, there is only anecdotal evidence around Omicron’s severity which suggests milder disease.

Prof Dame Sarah Gilbert, one of the creators of the Oxford/AstraZeneca vaccine, echoed the warning that vaccine effectiveness may be reduced against Omicron, noting its spike protein contained mutations known to increase the transmissibility of the virus. She cautioned that “there are additional changes that may mean antibodies induced by the vaccines, or by infection with other variants, may be less effective at preventing infection with Omicron.

“Until we know more, we should be cautious, and take steps to slow down the spread of this new variant.”

Preliminary results published in a preprint paper awaiting peer review suggest that the re-infection hazard ratio for Omicron is 2.39, with a possible range of  1.88–3.11 falling within the 95% confidence interval. By contrast, they found that the Beta and Delta variants proliferated primarily as a result of increased transmissibility, not immune escape.

Moderna Narrowly Beats Pfizer in Effectiveness

Image of a syringe for vaccination
Photo by Mika Baumeister on Unsplash

In the first head-to-head comparison of the effectiveness of the Pfizer-BioNTech and Moderna COVID vaccines, researchers examined the electronic health records of veterans who had received each vaccine and found Moderna to be slightly more effective.

The Moderna vaccine’s increased level of protection included a 21% lower risk of documented infection and 41% lower risk of hospitalisation, according to the research team, whose findings were published in the New England Journal of Medicine.

“Both vaccines are incredibly effective, with only rare breakthrough cases,” said Dr J.P. Casas, a member of the research team. “But regardless of the predominant strain – Alpha earlier and then Delta later – Moderna was shown to be slightly more effective.”

Researchers designed their comparative effectiveness study to address the previously unanswered question of which of the two mRNA vaccines is more effective. Effectiveness outcomes were: documented COVID, symptomatic disease, hospitalisation, ICU admission, and death. The investigators drew on the database of US veterans who received one of the two COVID vaccines between early January 2021 and mid-May 2021.

As initially designed, the research focused on the Alpha variant that predominated at the time. The study matched 219 842 recipients of the Pfizer vaccine to the same number of recipients of the Moderna vaccine. The two groups were matched based on a variety of clinical and demographic factors that could affect outcomes.

Over the study’s 24-week follow-up period, the estimated risk of documented infection was 4.52 events per 1000 people in the Moderna vaccine group and 5.75 per 1000 in the Pfizer group, an excess of 1.23 cases per 1000. The investigators also observed smaller excesses of symptomatic COVID (0.44 events), hospitalisation (0.55 events), ICU admission (0.10 events), and death (0.02 events) per 1000 people in the Pfizer group relative to the Moderna group.

This pattern of a lower risk for Moderna held up when Delta was the main strain. In this comparison, excess risk of documented infection over 12 weeks was 6.54 events per 1000 people for the Pfizer vaccine, compared to Moderna. Given the shorter time frame available for this supplementary research, infection was the only outcome researchers analyzed. Also, the estimates were considered less precise because a smaller number of individuals were eligible for this analysis.

Randomised trials comparing the mRNA vaccines against placebos had previously shown both vaccines to be very effective against symptomatic COVID infection (95% effectiveness for Pfizer-BioNTech, 94% for Moderna), borne out by real-world vaccine use.

“Given the high effectiveness of both the Moderna and Pfizer vaccines, confirmed by our study, either one is recommended to any individual offered a choice between the two,” said first author Dr Barbra A. Dickerman. “However, while the estimated differences in effectiveness were small on an absolute scale, they may be meaningful when considering the large population scale at which these vaccines are deployed. This information may be helpful for larger decision-making bodies.”

The massive Veteran Association records system supported a very large sample size. This, in turn, allowed the study to identify even small differences in effectiveness between the Pfizer and Moderna vaccines. The researchers used a methodology known as causal inference to mirror a gold standard randomised trial as closely as possible. Causal inference is a type of data analysis that helps researchers draw firm conclusions about cause and effect.

Using the VA database, vaccine recipients were closely matched on age, sex, race, geographic location, and other attributes that could affect COVID-related outcomes.

“After this careful matching, we found that the two vaccine groups were extremely similar in terms of variables with respect to an extensive set of demographic, geographic, and health-related attributes,” Dr Dickerman said. “This allowed our observational analysis to produce exceptionally credible results during a global emergency, when answers are needed fast and randomised trials can be impractical.”

As the global pandemic continues to unfold, the research team is working on answers relating to the comparative safety, versus effectiveness, of the Pfizer and Moderna vaccines. Dr Dickerman characterises comparative safety as an “additional piece of the puzzle to support vaccine decision-making.”

Even beyond this analysis, further evaluation of the vaccines’ comparative effectiveness and safety is needed, the authors concluded. Meanwhile, given the evidence at hand, the authors concluded about the Pfizer and Moderna vaccines considered in their study, “Given the high effectiveness and safety profile of both mRNA vaccines, either one is strongly recommended.”

Source: EurekAlert!

Six Different Booster Vaccines Found to be Safe and Effective

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The first randomised trial of COVID boosters, published in The Lancet, has shown that six are safe and provoke strong immune responses. Participants have previously received a two-dose course of ChAdOx1-nCov19 (Oxford–AstraZeneca [ChAd]) or BNT162b2 (Pfizer-BioNTech [BNT]). The announcement comes just as the Omicron variant is beginning to spread around the world.

ChAd has now been deployed in more than 180 countries and BNT in more than 145 countries. Several studies show that two doses of ChAd and BNT confer 79% and 90% protection, respectively, against hospitalisation and death after six months. However, protection against COVID infection wanes in time, which has led to the consideration of boosters. However, there are currently little data on the comparative safety of COVID vaccines, and the immune responses they stimulate, when given as a third dose.

The COV-BOOST study looked at safety, immune response (immunogenicity) and side-effects (reactogenicity) of seven vaccines when used as a third booster jab. The vaccines studied were ChAd, BNT, NVX-CoV2373 (Novavax [NVX]), Ad26.COV2.S (Janssen [Ad26]), Moderna [mRNA1273], VLA2001 (Valneva [VLA]), and CVnCov (Curevac [CVn]).

“The side effect data show all seven vaccines are safe to use as third doses, with acceptable levels of inflammatory side effects like injection site pain, muscle soreness, fatigue. Whilst all boosted spike protein immunogenicity after two doses of AstraZeneca, only AstraZeneca, Pfizer-BioNTech, Moderna, Novavax, Janssen and Curevac did so after two doses of Pfizer-BioNTech”, commented Professor Saul Faust, trial lead.

“It’s really encouraging that a wide range of vaccines, using different technologies, show benefits as a third dose to either AstraZeneca or Pfizer-BioNTech. That gives confidence and flexibility in developing booster programmes here in the UK and globally, with other factors like supply chain and logistics also in play”, added Prof Faust.

“It’s important to note that these results relate only to these vaccines as boosters to the two primary vaccinations, and to the immune response they drive at 28 days. Further work will generate data at three months and one year after people have received their boosters, which will provide insights into their impact on long-term protection and immunological memory. We are also studying two of the vaccines in people who had a later third dose after 7-8 months although results will not be available until the new year.”

A randomised, phase 2 trial of seven booster vaccines was conducted, with the third doses given 10-12 weeks after initial two-dose courses of ChAd or BNT. The trial involved 2878 healthy participants between June 1st and June 30th 2021. Participants had received their first doses of ChAd or BNT in December 2020, January or February 2021, and second doses at least 70 days before enrolment for ChAd and at least 84 days for BNT. About half of participants received two doses of ChAd and half two doses of BNT. The control vaccine used was a meningococcal conjugate vaccine (MenACWY).

Participants were aged 30 or older, roughly half of whom were 70 or older. The average age of participants who received ChAd was 53 years in the younger age group and 76 years in the older age group. Average ages for BNT were 51 and 78 years, respectively.

Thirteen experimental and control arms of the trial (seven vaccines plus three at half dose and three control arms) were split into three participant groups. Group A received NVX, half dose NVX, ChAd, or a control. Group B received BNT, VLA, half dose VLA, Ad26 or a control. Group C received Moderna, CVn (development of which was halted in October 2021), half dose BNT, or a control.

Primary outcomes were adverse effects seven days after receiving a booster, and levels of antibodies targeting the SARS-CoV-2 Spike protein after 28 days, compared to controls. Secondary outcomes included the response of T cells to wild type, Alpha, Beta, and Delta variants. 

Increases in anti-spike protein antibody levels after 28 days varied across the vaccines. After two doses of ChAd these ranged from 1.8 times higher to 32.3 times higher according to the booster vaccine used. Following two doses of BNT, the range was 1.3 times higher to 11.5 times higher. Significant T-cell responses were reported in several combinations.

At 28 days, all booster results were similar for participants aged 30-69 years and those aged 70 years or older. Boost ratios should be interpreted with caution, the authors caution, since they relate to immunogenicity rather than protection against disease, and the relationship between antibody levels at day 28 and long-term protection and immunological memory is unknown.

Reactions to all seven vaccines were similar, with fatigue, headache, and injection site pain most often reported. These were more commonly reported by those aged 30-69. 912 of the 2878 participants experienced a total of 1036 adverse events, 24 of which were severe.

Source: EurekAlert!

Mechanism Behind AstraZeneca and J&J Vaccine Blood Clots Found

A cloud of platelet factor 4 proteins interacting with the electrostatic surface of the Oxford vaccine, as seen through the computational microscope.
Credit: Chun Kit Chan, Arizona State University

An international team of scientists believe they may have found a molecular mechanism behind the extremely rare blood clots linked to adenovirus vaccines.

Scientists led by a team from Arizona State University, Cardiff University and others worked with AstraZeneca to investigate vaccine-induced immune thrombotic thrombocytopenia (VITT), also known as thrombosis with thrombocytopenia syndrome (TTS), a life-threatening condition seen in a very small number of people after receiving the Oxford-AstraZeneca or Johnson & Johnson vaccines.

“The mechanism which results in this condition, termed vaccine-induced immune thrombotic thrombocytopenia (VITT), was unknown,” said Abhishek Singharoy, an Arizona State University scientist and corresponding author of the study who teamed up to lead an international effort to tease out the details. 

Together, the team worked to solve the structural biology of the vaccine, and see the molecular details that may be at play, utilising state-of-the cryo-EM technology to analyse the AstraZeneca vaccine in minute detail. They sought to understand whether the ultra-rare side effect could be linked to the viral vector which is used in many vaccines, including those from Oxford/AstraZeneca and Johnson & Johnson.

Their findings suggest it is the viral vector – in this case, an adenovirus used to shuttle the coronavirus’ genetic material into cells – and the way it binds to platelet factor 4 (PF4) once injected that could be the potential mechanism.

In very rare cases, the scientists suggest, the viral vector may enter the bloodstream and bind to PF4, where the immune system then views this complex as foreign. They believe this misplaced immunity could result in the release of antibodies against PF4, which bind to and activate platelets, leading to clustering and blood clotting.

“It’s really critical to fully investigate the vector-host interactions of the vaccine at a mechanistic level,” said Singharoy. “This will assist in understanding both how the vaccine generates immunity, and how it may lead to any rare adverse events, such as VITT.”

Their findings were published in Science Advances.

Adenovirus expert Professor Alan Parker said: “VITT only happens in extremely rare cases because a chain of complex events needs to take place to trigger this ultra-rare side effect. Our data confirms PF4 can bind to adenoviruses, an important step in unravelling the mechanism underlying VITT. Establishing a mechanism could help to prevent and treat this disorder.”

“We hope our findings can be used to better understand the rare side effects of these new vaccines – and potentially to design new and improved vaccines to turn the tide on this global pandemic.”

The AstraZeneca and Johnson & Johnson vaccines both use an adenovirus to carry SARS-CoV-2 Spike proteins to trigger an immune response.

Since VITT was seen in both vaccines, scientists wondered whether the viral vector was involved. Additionally, neither the Moderna nor Pfizer vaccines, both mRNA vaccines, showed this effect.

Using cryo-EM technology to flash-freeze preparations of ChAdOx1, the adenovirus used in the AstraZeneca vaccine, they produce microscopic images of the vaccine components.

They were then able to view the viral capsid structure and other critical proteins that allow entry of the virus into the cell.

In particular, the team outlined the details for the structure and receptor of ChAdOx1, which is adapted from chimpanzee adenovirus Y25 – and how it interacts with PF4. They believe it is this specific interaction – and how it is then presented to the immune system – that could cuase the immune system to see it as foreign and release antibodies against this self-protein.

The research team also used computational models to show that one of the ways the two molecules tightly bind is via electrostatic interactions. The group showed that ChAdOx1 is mostly electronegative, attracting other positively charged molecules to its surface.

First author Dr Alexander Baker said: “We found that ChAdOx1 has a strong negative charge. This means the viral vector can act like a magnet and attract proteins with the opposite, positive charge, like PF4.” Baker is a member of ASU’s Biodesign Center for Applied Structural Discovery and an Honorary Research Fellow at Cardiff University School of Medicine.

“We then found that PF4 is just the right size and shape that when it gets close to ChAdOx1 it could bind in between the negatively charged parts of ChAdOx1’s surface, called hexons.”

The research team are hopeful that armed with a better understanding of what may be causing rare VITT they can provide further insights into how vaccines and other therapies, which rely on the same technology, might be altered in the development of the next generation vaccines and therapies.

“With a better understanding of the mechanism by which PF4 and adenoviruses interact there is an opportunity to engineer the shell of the vaccine, the capsid, to prevent this interaction with PF4. Modifying ChAdOx1 to reduce the negative charge may reduce the chance of causing thrombosis with thrombocytopenia syndrome,” said Baker.

The team likened it to the ‘two birds, one stone’ effect. The key contacts of individual amino acids that are essential to the capsid protein’s proteins interaction with PF4 can removed or substituted.

“The modification of the ChAdOx1 hexons to reduce their electronegativity may solve two problems simultaneously: reduce the propensity to cause VITT to even lower levels, and reduce the levels of pre-existing immunity, thus helping to maximize the opportunity to induce robust immune responses, said Singharoy.”

Source: EurekAlert!

Paxlovid Ramped up and No ‘Red Flags’ for Omicron Yet

Image by Quicknews

In the face of a renewed global surge in COVID cases, Pfizer has ramped up production of Paxlovid, even while the efficacy of Merck’s molnupiravir appears to be less than believed.

Pfizer is now expecting to make 80 million courses of Paxlovid by the end of 2022, Pfizer CEO Albert Bourla told CNBC, a significant increase over its earlier planned capacity of 50 million courses.

This news came after Merck reported the risk reduction in hospitalisation and death from its COVID antiviral, molnupiravir, fell from 50% in the interim analysis to 30% in the final analysis. The reduction came after results were updated with participants that became evaluable after the interim analysis. This drop has led to predictions of increased demand for Paxlovid, which has shown an 89% risk reduction in outpatients.

The increase in production comes just in time to fight the Omicron variant, for which South Africa is now better prepared, according to experts.

‘No red flags’
According to Professor Salim Abdool Karim, director of the Centre for the Aids Programme of Research in South Africa, the numbers appear to be on the rise across all continents, but as yet there are “no red flags” he said.

Omicron has been identified by South African scientists as a major driver of the spike in cases in Gauteng.

“We have been amazed at how fast the numbers are going up,” he said. “But we were not caught with our pants down. We expected and prepared for a fourth wave. [The scientists] gave us the best fighting chance by giving us information early. We didn’t know exactly when it would come and what it would look like,” Prof Karim said, speaking to the Daily Maverick.

While a number of mutations enable the variant to escape immunity, a clear picture of Omicron’s nature won’t emerge for two to four weeks, he cautioned.

Speaking about travel bans imposed on South Africa by Mauritius, Rwanda, Egypt and the Seychelles, President Cyril Ramaphosa said ahead of a West African tour: “I am concerned. Out of due respect to them, they have their own reasons. We would like to have a discussion with them in a way we prefer that they do not react like our former colonisers who are very quick to close Africa down,” Ramaphosa told journalists.

EU accelerates child vaccinations
EU President von der Leyen has said that vaccines for children aged five to 11 will be available in the bloc by December 13, a week ahead of schedule and that she is pushing for the consideration of mandatory vaccination. This comes amidst news that Omicron was detected in the Netherlands before its first detection in South Africa. Meanwhile, in Asia, South Korea has reported its first five cases of Omicron.

How One Hospital Met the COVID Surge Head-on

Photo by Artem Podrez on Unsplash

Since March of 2020, the COVID pandemic has put an unprecedented strain on hospitals as large surges of intensive care unit patients overwhelmed hospitals. To meet this challenge, Beth Israel Deaconess Medical Center (BIDMC) expanded ICU capacity by 93% and maintained surge conditions during the nine weeks in the first quarter of 2020.

In a pair of papers and a guest editorial published in Dimensions of Critical Care Nursing, a team of nurse-scientists at Beth Israel Deaconess Medical Center (BIDMC) report on almost doubling the hospital’s ICU capacity; identifying, training and redeploying staff; and developing and implementing a proning team to manage patients with acute respiratory distress syndrome during the first COVID surge.

“As COVID was sweeping through the nation, we at BIDMC were preparing for the projected influx of highly infectious, critically ill patients,” said lead author Sharon C. O’Donoghue, DNP, RN, a nurse specialist in the medical intensive care units at BIDMC. “It rapidly became apparent that a plan for the arrival of highly infectious critically ill patients as well as a strategy for adequate staffing protecting employees and assuring the public that this could be managed successfully were needed.”

After setting up a hospital incident command structure to clearly define roles, open up lines of communication and develop surge plans, BIDMC’s leadership began planning for the impending influx of COVID patients in February 2020.

BIDMC – a 673 licensed bed teaching hospital affiliated with Harvard Medical School – has nine specialty ICUs located on two campuses for a total of 77 ICU beds. Informed by an epidemic surge drill conducted at BIDMC in 2012, it was determined that the trigger to open extra ICU space would be when 70 ICU beds were occupied. When this milestone was met on March 31, 2020, departmental personnel had a 12-hour window to convert two 36-bed medical-surgical units into additional ICU space, providing an additional 72 beds.

“Because the medical-surgical environment is not designed to deliver an ICU level of care, many modifications needed to be made and the need for distancing only added to the difficulties,” said senior author Susan DeSanto-Madeya, PhD, RN, FAAN, a Beth Israel Hospital Nurses Alumna Association endowed nurse scientist. “Many of these rooms were originally designed for patient privacy and quiet, but a key safety element in critical care is patient visibility, so we modified the spaces to accommodate ICU workflow.”

Modifications included putting windows in all patient room doors, and repositioning beds and monitors so patients and screens could be easily seen without entering the room. Lines of visibility were augmented with mirrors and baby monitor systems as necessary. Care providers were given two-way radios to decrease the number of staff required to enter a room when hands-on patient care was necessary. Mobile supply carts and workstations helped streamline workflow efficiency.

Besides stockpiling and managing medical equipment including PPE, ventilators and oxygen, increasing ICU capacity also required redeploying 150 staff trained in critical care. The hospital developed a recall list for former ICU nurses, as well as medical-surgical nurses that could care for critically ill patients on teams with veteran ICU nurses.

Education and support was provided from . In-person, socially-distanced workshops were developed for each group, after which nurses were assigned to shadow an ICU nurse to reduce anxiety, practice new skills and gain confidence.

“Staff identified the shadow experience as being most beneficial in preparing them for deployment during the COVID surge,” said O’Donoghue. “Historically, BIDMC has had strong collaborative relationships with staff from different areas and these relationships proved to be vital to the success of all the care teams. The social work department played a major role in fostering teams, especially during difficult situations.”

One of the redeployment teams was the ICU proning team. Proning is known to improve oxygenation in patients with acute respiratory distress syndrome is a complex intervention, takes time and is not without its potential dangers to the patient and staff alike. The coalition maximised resources and facilitated more than 160 interventions between March and May of 2020.

“Although the pandemic was an unprecedented occurrence, it has prepared us for potential future crises requiring the collaboration of multidisciplinary teams to ensure optimal outcomes in an overextended environment,” O’Donoghue said. “BIDMC’s staff rose to the challenge, and many positive lessons were learned from this difficult experience.”

“We must continue to be vigilant in our assessment of what worked and what did not work and look for ways to improve health care delivery in all our systems,” said DeSanto-Madeya, who is also an associate professor at the College of Nursing at the University of Rhode Island. “The memories from this past year and a half cannot be forgotten, and we can move forward confidently knowing we provided the best care possible despite all the hardships.”

Source: Beth Israel Deaconess Medical Center

Pharma Giants Draw Their Plans Against Omicron

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As world leaders seek to reassure an anxious world about the emergence of Omicron, Moderna’s CEO believes that vaccines will not have the same level of effectiveness against the new variant. Meanwhile, other major vaccine developers such as Oxford University maintain that it is still too early as yet to draw conclusions, and existing vaccines can be updated in a matter of months.

In an interview with the Financial Times, Moderna CEO Stéphane Bancel said that “in no world” would vaccines protect against Omicron at the same level as they did against Delta. He added that he thought it would be “material drop”, though data was still to come. However, the scientists he spoke to had all said “‘This is not going to be good’.” This is because 32 of the variant’s 50 mutations are on the Spike protein, which current vaccines are designed to target.

He noted the reduced effectiveness of existing vaccines against Delta, saying that scientists had not expected such a high level of mutation to emerge for another two to three years. His comments come in stark contrast to others who stress that there is no information yet to suggest that Omicron is any more serious than previous variants, or that vaccines are less effective against it.

Oxford University released a statement saying they were monitoring the situation, but stood ready to produce a new vaccine if necessary.

“Despite the appearance of new variants over the past year, vaccines have continued to provide very high levels of protection against severe disease and there is no evidence so far that Omicron is any different.

“However, we have the necessary tools and processes in place for rapid development of an updated COVID vaccine if it should be necessary.”

Pfizer’s CEO Albert Bourla said in an interview with CNBC that his company had already started work on an updated vaccine, which would be ready in 100 days.

In the Netherlands, scientists from the country’s National Institute of Public Health said that they had detected Omicron on flights that had arrived from Southern Africa before the official announcement of the discovery by South Africa. The country is now trying to locate and isolate some 5000 individuals who arrived in the country from the region. 

Kids’ Spit Could be a Great COVID Test

Photo by CDC

Saliva samples are easy to obtain and useful for measuring antibodies to SARS-CoV-2 in children, which could improve epidemiological surveillance in school settings. The study followed over 1500 children who went to summer schools in Barcelona last year. The results were published in BMC Medicine.

One of the pressing questions during this pandemic has been to understand children’s susceptibility to SARS-CoV-2 infection and how they infect others. An obstacle to answer this question is that most infections in children are mild or asymptomatic, and are therefore missed. To establish whether an individual has been exposed to SARS-CoV-2 in the past, virus-specific antibodies in blood need to be detected. Measuring antibody prevalence over time in a cohort of children can provide very valuable epidemiological information. However, this requires techniques that are both sensitive and minimally invasive.

In this study, performed through the Kids Corona platform, the team led by Carlota Dobaño, from the Barcelona Institute for Global Health (ISGlobal), and Iolanda Jordan, from Hospital Sant Joan de Déu (HSJD), used saliva instead of blood to measure virus-specific antibodies in over 1500 children who attended different summer schools in Barcelona in 2020, as well as around 400 adult staff. Two saliva samples per participant were analysed, one at the beginning and one at the end of the camp stay, and different antibody types (IgG, IgA and IgM) targeting different viral antigens were measured.

The study found that 3.2% of the participants developed antibodies between the first and second sample, indicating new infections. This is six times higher than the infection rate estimated by weekly PCR screening. “It has been reported that some children can be positive for antibodies despite being negative by PCR, which suggests that they can generate an immune response that prevents the establishment of SARS-CoV-2 infection,” explained Dobaño, first author of the study. It could also be because asymptomatic children have lower viral loads or that their viral clearance is faster.

Furthermore, the analysis shows that the percentage of new infections was higher in adults (2.94%) than in children (1.3%), suggesting differences in infection and transmission dynamics. Finally, contrary to blood tests, asymptomatic people had higher levels of anti-Spike antibodies in saliva, suggesting these antibodies play a protective role in respiratory mucosae. “This means that anti-Spike antibodies in saliva could be used to measure protective immunity upon vaccination, especially in the case of intranasal vaccines,” said senior study co-author Gemma Moncunill.

“We previously demonstrated in other Kids Corona studies that saliva is useful for detecting virus by PCR. With this study, we demonstrate that it’s also an effective and much friendlier way to measure antibodies, making it the ideal sample for children, instead of the more invasive nasal swab,” said Jordan.

Source: EurekAlert!

About 1% of Hospitalised COVID Patients Develop Neurological Complications

49-year-old female with past medical history of mitral valve disease and tricuspid valve regurgitation who developed headache followed by cough and fever presented to the ER with right upper eyelid ptosis (drooping). Credit: Radiological Society of North America and Scott H. Faro, M.D.

Approximately one in 100 patients hospitalised with COVID will likely develop complications of the central nervous system, according to a large international study. These can include stroke, haemorrhage, and other potentially fatal complications. The study was presented at the annual meeting of the Radiological Society of North America (RSNA).

“Much has been written about the overall pulmonary problems related to COVID, but we do not often talk about the other organs that can be affected,” said study lead author Scott H. Faro, MD, FASFNR, professor of radiology and neurology at Thomas Jefferson University. “Our study shows that central nervous system complications represent a significant cause of morbidity and mortality in this devastating pandemic.”

Dr Faro initiated the study after finding that only a small number of cases informed existing literature on central nervous system complications in hospitalised COVID patients.

To build a more complete picture, he and his colleagues analysed nearly 40 000 cases of hospitalised COVID patients, admitted between September 2019 and June 2020. Their average age was 66 years old, and two thirds were men.

Confusion and altered mental status were the most common causes of admission followed by fever. Comorbidities such as hypertension, cardiac disease and diabetes were common.

There were 442 acute neuroimaging findings most likely associated with the viral infection, with central nervous system complications in 1.2% of this large patient group.

“Of all the inpatients who had imaging such as MRI or a CT scan of the brain, the exam was positive approximately 10% of the time,” Dr Faro said. “The incidence of 1.2% means that a little more than one in 100 patients admitted to the hospital with COVID are going to have a brain problem of some sort.”

Ischaemic stroke, with an incidence of 6.2%, was the most common complication, followed by intracranial haemorrhage (3.72%) and encephalitis (0.47%).

A small percentage of unusual findings was uncovered, such as acute disseminating encephalomyelitis, an inflammation of the brain and spinal cord, and posterior reversible encephalopathy syndrome, a syndrome that mimics many of the symptoms of a stroke.

“It is important to know an accurate incidence of all the major central nervous system complications,” Dr Faro said. “There should probably be a low threshold to order brain imaging for patients with COVID.”

Source: EurekAlert!