In a new study, 85% of a Seattle fishing boat crew were infected onboard with COVID-19 in May. The entire crew had tested negative for infection and had blood drawn before departure. Upon return, the three people who had neutralizing antibodies before departure were not infected on the ship.
The big question is, how long are COVID-19 antibodies protective? It depends on the titers, or the concentration of antibodies, in an individual's blood.
People with more severe COVID-19 infection probably have more antibodies, which could possibly protect them from reinfection for a year or more. Milder infections lead to fewer antibodies and could possibly provide protection for up to 6 months.
Reinfection of COVID-19 is possible. Studies indicate that about 10% of people with mild infections show little immune response, increasing their risk for reinfection.
Reinfections are often milder and may be asymptomatic.
AstraZeneca today announced the temporary cessation of all their coronavirus vaccine trials to investigate an "unexplained illness" that arose in a participant.
The reported illness triggered a "standard review process" for the phase 3 trial of AZD1222, the company stated in a press release.
"As part of the ongoing randomized, controlled global trials, our standard review process was triggered and we voluntarily paused vaccination," an AstraZeneca spokesperson wrote in an email to Medscape Medical News when asked for more specifics on the unexplained illness.
"The event is being investigated by an independent committee," the spokesperson added, "and is it too early to conclude the specific diagnosis."
The New York Times, however, is reporting that the participant developed transverse myelitis, an inflammatory condition that affects the spinal cord, according to an anonymous source familiar with the situation.
Such a halt is "not uncommon at all," said Anthony Fauci, MD, head of the National Institute of Allergy and Infectious Diseases, in an interview on CBS This Morning. The illness may be unrelated to the vaccine and just happened to arise at the same time, he said, but "you can't presume that."
"This is an example of the kind of thing that you do to make sure when dealing with a product that it's safe," he said.
The company declined to provide a timeline for the safety review.
"We will be guided by this committee as to when the trials could restart, so that we can continue our work at the earliest opportunity to provide this vaccine broadly, equitably, and at no profit during this pandemic," AstraZeneca Chief Executive Officer Pascal Soriot said in the news release.
The news was first reported by Stat News yesterday.
Damian McNamara is a staff journalist based in Miami. He covers a wide range of medical specialties, including infectious diseases and neurology. Follow Damian on Twitter: @MedReporter.
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Russia's "Sputnik-V" COVID-19 vaccine produced an antibody response in all participants in early-stage trials, according to results published on Friday in The Lancet that were hailed by Moscow as an answer to its critics.
In the two trials, conducted in June-July and involving 76 participants, 100% of participants developed antibodies to the new coronavirus, with no serious side effects, the researchers said.
Russia licensed the two-shot jab for domestic use in August, the first country to do so and before any data had been published or a large-scale trial begun.
"The two 42-day trials – including 38 healthy adults each – did not find any serious adverse effects among participants, and confirmed that the vaccine candidates elicit an antibody response," the researchers said.
"Large, long-term trials including a placebo comparison, and further monitoring are needed to establish the long-term safety and effectiveness of the vaccine for preventing COVID-19 infection," they said.
The vaccine is named Sputnik-V in homage to the world's first satellite, launched by the Soviet Union. Some Western experts have warned against its use until all internationally approved testing and regulatory steps have been taken.
But with the results now published for the first time in an international peer-reviewed journal, and with a 40,000-strong later-stage trial launched last week, a senior Russian official said Moscow had faced down its critics abroad.
"With this (publication) we answer all of the questions of the West that were diligently asked over the past three weeks, frankly with the clear goal of tarnishing the Russian vaccine," said Kirill Dmitriev, the head of the Russian Direct Investment Fund (RDIF), Russia's sovereign wealth fund, which has backed the vaccine.
"All of the boxes are checked," he told Reuters. "Now... we will start asking questions of some of the Western vaccines."
Dmitriev said at least 3,000 people had already been recruited for the large-scale trial of the Sputnik-V vaccine launched last week, and initial results are expected in October or November.
Commenting on the results of the early-stage trials, Dr. Naor Bar-Zeev of the International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, USA said the studies were "encouraging but small."
Bar-Zeev, who was not involved in the study, said "clinical efficacy for any COVID-19 vaccine has not yet been shown."
RACE TO DEVELOP VACCINE
Governments and big pharmaceutical firms are racing to develop a vaccine to end the COVID-19 pandemic, which has killed more than 850,000 people globally and infected around 26 million.
More than half a dozen drugmakers are already conducting advanced clinical trials, each with tens of thousands of participants and several, including Britain's AstraZeneca and U.S. drugmakers Moderna and Pfizer expect to know if their COVID-19 vaccines work and are safe by the end of this year.
The Russian researchers said the early-stage trials suggested the Sputnik-V vaccine produced a T cell response.
Scientists have been scrutinizing the role played by T cells in battling coronavirus infection, with recent findings showing these cells may provide longer-term protection than antibodies.
The vaccine, developed by Moscow's Gamaleya Institute, is administered in two doses, with each based on a different vector that normally causes the common cold: human adenoviruses Ad5 and Ad26.
Some experts have said that using this delivery mechanism could make a COVID-19 vaccine less effective, since many people have already been exposed to the Ad5 adenovirus and developed immunity to it.
In China and the United States, about 40% of people have high levels of antibodies from prior Ad5 exposure. In Africa, it could be has high as 80%, experts have said.
Denis Logunov, one of the vaccine's developers at the Gamaleya Institute, told Reuters the vaccine uses a strong enough dose of Ad5 to overcome any earlier immunity, without compromising safety.
The booster dose, based on the rarer Ad26 adenovirus, provides further support because the likelihood of widespread immunity to both types in the population is minimal, he said.
Russia has said it expects to produce between 1.5 million and 2 million doses per month of its potential COVID-19 vaccine by the end of the year, gradually increasing production to 6 million doses a month.
SOURCE: https://bit.ly/3537RGg The Lancet, online September 4, 2020.
A COVID-19 saliva test protocol developed by researchers at Yale University appeared to perform at least as well as nasal swabs in a study of hospital patients, a finding that may help encourage more frequent use of self-collected samples.
In a letter published August 28 in the New England Journal of Medicine, Anne L. Wyllie, PhD, of the Yale School of Public Health, New Haven, Connecticut, and her coauthors reported on testing done on 70 patients. These patients already had tested positive for COVID-19, which was confirmed with a positive nasopharyngeal swab specimen at admission to Yale-New Haven Hospital.
Dr Anne L. Wyllie
At 1 to 5 days after diagnosis, 81% (95% CI, 71-96) of the saliva samples were positive, as compared with 71% (95% CI, 67-94) of the nasopharyngeal swab specimens, Wyllie and coauthors report in the NEJM paper.
Wyllie told Medscape Medical News that, at days 6 to 10 after diagnosis, 76% of the saliva samples were positive, as compared with 65% of the nasopharyngeal swab specimens. The results flip at the day 11 mark, with 41% of the saliva samples showing positive results, as compared with 50% of the nasopharyngeal swab specimens.
In the letter, Wyllie and coauthors also reported on screening results for 495 healthcare workers (ages 22-74 years; mean age, 37) who were asymptomatic for COVID-19. The researchers detected SARS-CoV-2 in saliva specimens obtained from 13 people who did not report any symptoms at or before the time of sample collection. Of these 13, nine had collected matched nasopharyngeal swab specimens by themselves on the same day and seven of these specimens tested negative. The 13 positive diagnoses were later confirmed with additional nasopharyngeal samples.
"Important Advance"
The NEJM publication expands on work previously reported by Wyllie and colleagues in an April preprint article posted to the site medRxiv.
These findings represent "an important advance in testing" for COVID-19, Jason Farley, PhD, MPH, of Johns Hopkins Schools of Nursing and Medicine, Baltimore, Maryland, told Medscape Medical News. An infectious disease-trained nurse epidemiologist, Farley was not involved in the Yale team work, but he has worked on efforts at Hopkins to test individuals using saliva samples to track COVID-19 infection.
The pragmatic approach used by the Yale team avoids the kind of issues with shortages of medical supplies that have hampered US testing, Farley said. Their approach relies on supplies hospital laboratories are likely to have on hand. The letter in NEJM, for example, said sterile urine cups were used to gather samples.
This moves us forward, especially with supply-chain issues," he said of the new research.
Wyllie and Nathan Grubaugh, PhD, of the Yale School of Public Health, last month secured an emergency use authorization from the US Food and Drug Administration (FDA) for a related test protocol, called SalivaDirect. This is a simplified version of the test described in the NEJM letter, with the researchers having eliminated the RNA extraction step. The FDA said this was the fifth test it had authorized that uses saliva as a sample for testing for COVID-19.
But Yale's approach with SalivaDirect is markedly different from that used with many diagnostics, as the webpage for the test notes.
"A common question that we receive is 'What company is behind this assay?' The answer is — well, there isn't one. We designed and validated SalivaDirect using several common and available reagents. If one reagent is out of stock or is too pricey, there are alternative reagents to use," says a backgrounder on the CovidTrackerCT website, created by members of Grubaugh's lab.
SalivaDirect is a protocol, not a kit, which is intended to help other medical institutions also do "inexpensive saliva-based" testing, the backgrounder said.
"I love the fact that they are sharing their protocols in an open-source way so that people can replicate the protocol," Farley said. The Yale team "really needs to be commended for that level of scientific integrity."
Also enthusiastic about this protocol is Andy Slavitt, who was administrator of the Centers for Medicare & Medicaid Services in the Obama administration. In a series of tweets on August 15, Slavitt said the Yale team is "turning testing from a bespoke suit to a low-cost commodity."
SalivaDirect "should create millions more in test capacity. Easy to use. High volume. Cheap. Widely available and accurate," he tweeted.
The University of Illinois, Urbana-Champaign, already has used the FDA's emergency use authorization for Yale's protocol as a path for using its own saliva testing at the school. The researchers performed what's called a "bridging study" that put their project under the umbrella of the FDA's emergency approval of the Yale test.
New Challenges
A challenge in COVID-19 testing is shifting institutions away from the kinds of tools they have been currently using and toward newer ones, said Martin Burke, MD, PhD a professor of chemistry at the University of Illinois, Urbana-Champaign.
The NEJM publication on Yale's research may assist with wider adoption of saliva-based tests, he told Medscape Medical News.
"I'm hopeful it is going to help overcome that inertia and help us get to a place where we could test much more [quickly] and frequently," said Burke, who is associate dean of research for the Carle Illinois College of Medicine, Champaign, Illinois.
"Saliva is the medium that matters. This is how we transmit SARS-Cov2 to one another primarily," he said. “So why not test the thing that is most important for that transmission?"His school is using its saliva test, called I-COVID, to screen faculty, staff, and students. The test can yield results in hours. The University of Illinois now is testing about 60,000 people twice a week, using this screening as part of its efforts to try to stay open amid the pandemic, Burke said.
Another advantage of the saliva tests is that they provide more than a binary yes-or-no answer about the infection, he said.
"You actually end up getting a quantitative readout on how many copies of viral RNA per milliliter in saliva," Burke said. "There's an extra dimension there of quantitative information that thus far we haven't really been taking advantage that could be a huge opportunity."Hopkins' Farley said implementing COVID-19 saliva tests for hospital patients outside of clinical tests will pose a few challenges for staff.
"There are some practical issues to think about as you think about the scale-up and how well the patients do and do not understand the actual instructions they are given," Farley said, adding, however, that the problems are manageable.
Yale's Wyllie said the research in the NEJM paper shows saliva to be at least as good as nasal swabs, and possibly better. And for SalivaDirect with a sensitivity of 6-12 virus RNA copies/µL it is still comparable to many other available PCR tests, she said.
Greater availability and ease of COVID-19 tests is critical to preventing spread of the virus, she added.
"People need to stop thinking about just diagnostic testing," Wyllie said. "We need to have screening testing going forward. These screening tests don't necessarily have to be of the same standards as diagnostic tests."
This work was supported by the Huffman Family Donor Advised Fund, a Fast Grant from Emergent Ventures at the Mercatus Center at George Mason University, the Yale Institute for Global Health, the Yale School of Medicine, a grant (U19 AI08992, to Dr. Ko) from the National Institute of Allergy and Infectious Diseases, the Beatrice Kleinberg Neuwirth Fund, and a grant (Rubicon 019.181EN.004, to Dr. Vogel) from the Dutch Research Council (NWO). In disclosures forms, the authors reported grants and personal fees outside of this work from Pfizer, Bristol-Myers Squibb, Regeneron, Serimmune, and the National Basketball Association.
The immune system overactivation known as a "cytokine storm" does not play a major role in more severe COVID-19 outcomes, according to unexpected findings in new research. The findings stand in direct contrast to many previous reports.
"We were indeed surprised by the results of our study," senior study author Peter Pickkers, MD, PhD, told Medscape Medical News.
In a unique approach, Pickkers and colleagues compared cytokine levels in critically ill people with COVID-19 to those in patients with bacterial sepsis, trauma, and after cardiac arrest.
"For the first time, we measured the cytokines in different diseases using the same methods. Our results convincingly show that the circulating cytokine concentrations are not higher, but lower, compared to other diseases," said Pickkers, who is affiliated with the Department of Intensive Care Medicine at Radboud University Medical Center in Nijmegen, the Netherlands.
The team's research was published online on September 3 in a letter in JAMA.
Cytokines Lower Than Expected
Normally, cytokines trigger inflammation and promote healing after trauma, infection, or other conditions.
Although a cytokine storm remains ill defined, the authors note, many researchers have implicated a hyperinflammatory response involving these small proteins in the pathophysiology of COVID-19.
The question remains, however, whether all cytokine storms strike people with different conditions the same way.
Pickkers, lead author Matthijs Kox, PhD, and colleagues studied 46 people with COVID-19 and acute respiratory distress syndrome (ARDS) who were admitted to the ICU at Radboud University Medical Center. All participants underwent mechanical ventilation and were treated between March 11 and April 27, 2020.
The investigators measured plasma levels of cytokines, including tumor necrosis factor (TNF), interleukin-6 (IL-6), and interleukin-8 (IL-8). They compared results in this group to those in 51 patients who experienced septic shock and ARDS, 15 patients with septic shock without ARDS, 30 people with out-of-hospital cardiac arrest, and 62 people who experienced multiple traumas. They used historical data for the non-COVID-19 cohorts.
Conditional Findings
Compared to patients with septic shock and ARDS, the COVID-19 cohort had lower levels of TNF, IL-6, and IL-8. The differences were statistically significant for TNF (P < .01), as well as for IL-6 and IL-8 concentrations (for both, P < .001).
In addition, the COVID-19 group had significantly lower IL-6 and IL-8 concentrations compared with the patients who had septic shock without ARDS.The researchers likewise found lower concentrations of IL-8 in patients with COVID-19 compared to the out-of-hospital cardiac arrest patients. IL-8 levels did not differ between the COVID-19 and trauma groups.
Furthermore, the researchers found no differences in IL-6 concentrations between patients with COVID-19 and those who experienced out-of-hospital cardiac arrest or trauma.
However, levels of TNF in people with COVID-19 were higher than in trauma patients.
The small sample sizes and single-center study design are limitations.
"The findings of this preliminary analysis suggest COVID-19 may not be characterized by cytokine storm," the researchers note. However, they add, "Whether anticytokine therapies will benefit patients with COVID-19 remains to be determined."
Going forward, Pickkers and colleagues are investigating the effectiveness of different treatments to lower cytokine levels. They are treating people with COVID-19, for example, with the IL-1 cytokine inhibitor anakinra and steroids.
They also plan to assess the long-term effects of COVID-19 on the immune system. "Following an infection, it is known that the immune system may be suppressed for a longer period of time, and we are determining to what extent this is also present in COVID-19 patients," Pickkers said.
Enough to Cause a Storm?
The study "is quite interesting, and data in this paper are consistent with our data," Tadamitsu Kishimoto, MD, PhD, of the Department of Immune Regulation at the Immunology Frontier Research Center at Osaka University, Osaka, Japan, told Medscape Medical News when asked to comment.
His study, published online August 21 in PNAS, also revealed lower serum IL-6 levels among people with COVID-19 compared to patients with bacterial ARDS or sepsis.
Kishimoto drew a distinction, however: COVID-19 patients can develop severe respiratory failure, suggesting a distinct immune reaction compared to patients with bacterial sepsis. SARS-CoV-2 directly infects and activates endothelial cells rather than macrophages, as occurs in sepsis.
For this reason, Kishimoto said, "SARS-CoV-2 infection causes critical illness and severe dysfunction in respiratory organs and induces a cytokine storm," even in the setting of lower but still elevated serum IL-6 levels.
Pickkers and Kishimoto report no relevant financial relationships.
JAMA. Published online September 3, 2020. Abstract
Damian McNamara is a Medscape Medical News journalist based in Miami. He covers a wide range of medical specialties, translating research and breaking medical news into easy-to-understand, engaging stories for busy medical professionals. He reports news from major medical conference in the US and abroad. He can be reached on Twitter: @MedReporter.
For more news, follow Medscape on Facebook, Twitter, Instagram, and YouTube.
Skip kissing and consider wearing a mask when having sex to protect yourself from catching the coronavirus, Canada's chief medical officer said on Wednesday, adding that going solo remains the lowest risk sexual option in a pandemic.
Dr Theresa Tam said in a statement there is little chance of catching COVID-19 from semen or vaginal fluid, but sexual activity with new partners does increase the risk of contracting the virus, particularly if there is close contact like kissing.
"Like other activities during COVID-19 that involve physical closeness, there are some things you can do to minimize the risk of getting infected and spreading the virus," she said.
Skip kissing, avoid face-to-face closeness, wear a mask that covers your mouth and nose, and monitor yourself and your partner for symptoms ahead of any sexual activity, Tam said.
"The lowest risk sexual activity during COVID-19 involves yourself alone," she added.
Sexual health is an important part of overall health, Tam said, and by taking precautions, "Canadians can find ways to enjoy physical intimacy while safeguarding the progress we have all made containing COVID-19."
Canada has reported 129,425 cases of COVID-19 and 9,132 deaths, as of Sept 1. New daily cases are far below peak volumes, but there has been a recent uptick, driven by more infections in certain western Canadian provinces.
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