Share on PinterestMichael Ciaglo/Getty ImagesCOVID-19 is a respiratory disease caused by the SARS-CoV-2 virus.Researchers across the globe are working to develop a vaccine.Currently, there are 135 candidate vaccines.Today, there are 40 candidate vaccines in stage 3 clinical trials.So far, 21 vaccines have been authorized across several countries.For general COVID-19 updates visit our live blog.
07/29/2021 15:50 GMT — No extra risk of blood clots with 2nd dose of AstraZeneca COVID-19 vaccine
The second dose of the Oxford/AstraZeneca vaccine does not cause an increased risk of blood clotting, a new study has confirmed.
Examining over 49 million people across the European Union, the European Economic Area, and the United Kingdom, the study found the first dose of the viral vector vaccine carries a small extra risk of rare blood clots with low platelets.
The study also echoed previous reports, which found that most blood clotting incidents occurred two weeks after the first dose of vaccine was administered.
After the first dose of the vaccine, estimates showed that the risk of thrombosis with thrombocytopenia syndrome was 8.1 per million. After the second dose, the rate dropped to 2.3 per million, level with unvaccinated people, the company said.
There are “no specific risk factors or definitive cause” for blood clotting issues associated with the vaccine, but investigations will continue, it added.
The vaccine saw its uptake decline after reports of this rare side effect surfaced across the globe.
Experts now hope that the new study, published this week in The Lancet, will instill more confidence in the AstraZeneca vaccine and encourage people to receive their second dose.
For more information about COVID-19 vaccine side effects, check out this MNT feature.
07/29/2021 13:55 GMT — 3rd dose of Pfizer COVID-19 vaccine ‘strongly’ increases protection against Delta variant
Pfizer/BioNTech has said that a third dose of its COVID-19 vaccine can “strongly” boost the protection it provides against the more infectious Delta variant compared with its standard two-dose regimen.
In trials, the third dose produced five times more antibodies against the Delta variant in people aged 18–55 years and 11 times more antibodies in those aged 65–85 years.
The third dose also provided higher protection against both the original coronavirus strain and the Beta variant. The Pfizer vaccine had shown robust protection against severe disease with the Beta variant but slightly reduced protection against symptomatic disease and infection with two doses.
Pfizer released the new data on Wednesday on the preprint platform MedRxiv.
Among the safety and efficacy data released were also updates about the vaccine’s protection window.
Pfizer said that the protection provided by its COVID-19 vaccine can last for at least 6 months but that it may wane around that time. This was the finding from an Israeli study that prompted the company to further explore booster shots.
In light of the data and a fourth COVID-19 wave, the Israeli Health Ministry also approved booster shots to be administered to older adults. The decision came a few hours after the release of the data.
Despite the data having not undergone peer review, scientists have called it “encouraging.”
Read more about vaccine boosters in this MNT feature.
07/27/2021 10:09 GMT — Second mRNA vaccine dose safe even after an allergic response to the first dose
An estimated 2% of people have allergic reactions to mRNA COVID-19 vaccines, such as the Pfizer-BioNTech and Moderna vaccines. The vast majority of these reactions are not severe. A recent research letter, which appears in JAMA Internal Medicine, investigated how these individuals responded to their second dose.
The analysis included data from 159 participants who had exhibited an allergic response to their first dose of mRNA vaccine and went on to have a second dose.
Of the 159 participants, 47 took an antihistamine medication before their second dose. According to the authors:
“All 159 patients, including 19 individuals with first-dose anaphylaxis, tolerated the second dose. Thirty-two (20%) reported immediate and potentially allergic symptoms that were associated with the second dose that were self-limited, mild, and/or resolved with antihistamines alone.”
07/27/2021 09:37 GMT — COVID-19 vaccine: If you had no side effects, are you protected?
In a recent feature, Medical News Today addressed a common question: Is there a relationship between side effects after vaccination and subsequent immunity? In other words, if you do not experience side effects, are you still protected?
Read the feature here.
07/26/2021 13:48 GMT — UK study suggests that an interval of 6 weeks or more between Pfizer-BioNTech vaccine may elicit stronger immune response
According to a study funded by the Department of Health and Social Care for England, delivering the two doses of the Pfizer-BioNTech vaccine at an interval of 6 weeks or more increases concentrations of neutralizing antibodies against SARS-CoV-2.
Pfizer and BioNTech currently advise delivering the two vaccine doses at an interval of 3–4 weeks.
The research — whose findings the authors shared online in preprint form — followed the immune responses induced in 503 healthcare workers who received the Pfizer-BioNTech COVID-19 vaccine.
“The study showed the expected improvement to the immune response when a longer prime-boost interval was used,: Dr. Peter English, a retired consultant in communicable disease control and immediate past Chair of the BMA Public Health Medicine Committee, commented.
“In particular,” he added, “there was a higher neutralizing antibody response […] and there were enhancements to the cellular immunity, in particular to the parts of the immune system that provide ‘immune memory,’ so that there can be a vigorous and rapid response to exposure to the virus if it is encountered in the future.”
“In other words, it is likely to extend the duration of efficacy of vaccination.”
07/23/2021 10:18 GMT — EU promises to donate 200 million vaccine doses
The European Union has announced that it will send 200 million doses of COVID-19 vaccine to low and middle income countries. President of the European Commission Ursula von der Leyen said that the EU “takes its responsibility in helping the world fight the virus, everywhere.”
She continued to say, “Vaccination is key — that’s why it is essential to ensure access to COVID-19 vaccines to countries worldwide.”
Beyond vaccine donation, the EU is also helping African countries manufacture vaccines to reduce their dependence on imports.
Find more live COVID-19 updates here.
07/20/2021 14:15 GMT — Quarter-dose of Moderna vaccine still creates long-lasting immune response
New research, which has yet to be published in a peer-reviewed journal, finds that two shots of the Moderna COVID-19 vaccine, each containing only one quarter of the standard dose, were enough to trigger a long-lasting immune response.
The results are based on the analysis of blood samples from 35 participants who were enrolled in the original Moderna trial. Each participant received two 25-microgram (mg) shots of the vaccine 28 days apart. The standard dose of the Moderna vaccine is currently 100 mg.
Out of 35 participants, 33 developed an immune response after the first dose. Six months after the second shot, 29 out of 33 participants (88%) had neutralizing antibodies, which stop the virus from infecting healthy cells. Most of the participants also had robust T cell responses, which help the body make antibodies and can kill infected cells.
“It is quite remarkable — and quite promising — that you can easily detect responses for that long a time,” says study co-author Daniela Weiskopf, an immunologist at the La Jolla Institute for Immunology in California. The results suggest that using just a fraction of the dose might help make the most of the limited vaccine supplies and speed up global vaccination.
Read the full story here.
07/20/2021 13:57 GMT — Are COVID-19 vaccine boosters the way forward?
Read the full article here.
07/19/2021 12:36 GMT — COVID-19 vaccine hesitancy less prominent in low- and middle-income countries
According to research recently published in the journal Nature Medicine, there is less COVID-19 vaccine hesitancy among populations from low- and middle-income countries (LMICs),compared with those from high-income countries.
The research included seven studies conducted in low-income countries (Burkina Faso, Mozambique, Rwanda, Sierra Leone, and Uganda), five studies from lower-middle-income countries (India, Nepal, Nigeria, and Pakistan), and one study conducted in an upper-middle-income country (Colombia).
For contrast, it also looked at findings from two high-income countries that have been particularly active in the development of COVID-19 vaccines: the United States and Russia.
The findings indicate that in LMICs, the the average vaccine acceptance rate was 80.3%. They also showed that even the LMICs with the lowest rates — Burkina Faso and Pakistan — were doing better in terms of COVID-19 vaccine acceptance than the U.S. and Russia.
In both Burkina Faso and Pakistan, the vaccine acceptance rate was 66.5%. In the U.S., it stood at 64.6%, and in Russia at 30.4%.
Research co-author Dr. Alexandra Scacco, a senior research fellow at the WZB Berlin Social Science Center, notes that “Across countries, we observe that acceptance of COVID-19 vaccines is generally somewhat lower than for other vaccines, perhaps because of their novelty.”
“However,” Dr. Scacco adds, “the consistently pro-vaccine attitudes we see in [LMICs] give us reason to be optimistic about uptake.”
07/15/2021 09:06 GMT — COVID-19 vaccine distribution: Health and socioeconomic data key for equity
A recent study, which appears in PLOS Medicine, investigated whether considering localized estimates of health and socioeconomic factors could improve vaccine rollouts.
The results suggest that these factors together explain 43% of the variability in deaths across counties in the United States.
Read more about this study here.
07/14/2021 10:34 GMT — Rare neurological side effects with J&J and Oxford-AstraZeneca vaccines
Some people have developed Guillain-Barré syndrome, a neurological disorder that causes muscle weakness and paralysis, after receiving the Johnson & Johnson or Oxford-AstraZeneca vaccines, prompting some regulators to add warnings.
On July 9, the European Medicines Agency (EMA) recommended that a warning be added to the Oxford-AstraZeneca (Vaxzevria) COVID-19 vaccine “to raise awareness among healthcare professionals and people taking the vaccine of cases of Guillain-Barré syndrome reported following vaccination.”
At this stage, the EMA is unable to firmly conclude whether the vaccine directly causes Guillain-Barré syndrome, stating that “the available data neither confirms nor rules out a possible association with the vaccine.”
Earlier this week, the Food and Drug Administration (FDA) added a similar warning to Johnson & Johnson’s COVID-19 vaccine, noting that the “chance of having this occur is very low” and that most people experienced symptoms within 42 days of vaccination.
The FDA urges anyone who experiences weakness or tingling sensations, difficulty walking, vision problems, difficulty with bladder control or bowel function, or problems with facial movements, such as speaking, chewing, or swallowing, after receiving the shot to seek medical attention.
Read more about the side effects of COVID-19 vaccines here.
07/14/2021 10:21 GMT — CoronaVac vaccine data shows high levels of protection
Two new studies report that the inactivated CoronaVac vaccine is highly effective in protecting against severe COVID-19 that requires hospital treatment. Data from more than 10 million people in Chile suggest that the vaccine is 87.5% effective in preventing hospitalization.
Meanwhile, an interim analysis of a phase 3 clinical trial from Turkey found that the vaccine offered 100% protection against hospitalization. However, the study authors note that the trial only involved a very short follow-up period and that the volunteers had a low risk of serious disease.
Gathering real-world evidence, which involves far more people than any trial could, is crucial for understanding the true effectiveness of new vaccines, especially in the face of emerging variants.
Read our full analysis of the research here.
07/14/2021 08:55 GMT — Sputnik Light COVID-19 vaccine: Article highlights
07/13/2021 12:10 GMT — Sputnik Light COVID-19 vaccine: What we know
Russia has started rolling out its Sputnik Light COVID-19 vaccine, also known as Gam-COVD-Vac. However, some global health authorities argue that more tests are necessary to confirm the vaccine’s effectiveness before releasing it for mass circulation.
Medical News Today reviews the evidence that we have so far on the topic, in a feature which you can read here.
07/12/2021 11:40 GMT — Thailand mixes Oxford-AstraZeneca and Sinovac shots to prevent further spread of SARS-CoV-2
On Sunday, July 11, Thai authorities reported that, out of 677,000 health workers who had received both doses of the Sinovac COVID-19 vaccine, 618 still developed COVID-19 between April and July 2021, according to the BBC.
Sinovac is a two-dose inactivated vaccine developed by the China-based pharmaceutical company Sinovac Biotech. According to existing data, this vaccine has at least 50.4% efficacy in preventing symptomatic infection with SARS-CoV-2, the virus that causes COVID-19.
Yet the high number of COVID-19 cases among fully vaccinated health workers in Thailand has led the relevant authorities to advise that, following the first Sinovac shot, people should receive the Oxford-AstraZeneca COVID-19 vaccine for their second dose.
The Oxford-AstraZeneca vaccine is a two-dose viral vector vaccine, and it is currently the only other COVID-19 vaccine available in Thailand, aside from Sinovac.
07/09/2021 14:01 GMT — Can COVID-19 vaccines affect periods?
Read the full feature here.
07/09/2021 10:03 GMT — Pfizer chases authorization for third dose of vaccine
Yesterday, Pfizer announced that it will seek emergency authorization from the Food and Drug Administration (FDA) for a third dose of its vaccine. Although the Pfizer-BioNTech vaccine protects against the delta variant, a booster shot may enhance the immune response and provide longer-lasting protection.
The Pfizer press release explains:
“Pfizer and BioNTech have seen encouraging data in the ongoing booster trial of a third dose of the current BNT162b2 vaccine. Initial data from the study demonstrate that a booster dose given 6 months after the second dose has a consistent tolerability profile while eliciting high neutralization titers
against the wild type and the beta variant, which are 5 to 10 times higher than after two primary doses.”
In the press release, the company explains that 6 months after the vaccine, the protection against serious illness “remains high.” However, the protection against infection and symptomatic disease declines.
Based on the currently available data, “Pfizer and BioNTech believe that a third dose may be beneficial to maintain the highest levels of protection.”
07/08/2021 09:36 GMT — COVID-19 vaccines, immunity, and new variants: The role of T cells
Some SARS-CoV-2 variants of concern can evade neutralizing antibodies in vaccinated people. However, a recent study investigating these variants in individuals immunized with the Moderna and Pfizer vaccines found that the T cell response, unlike the antibody response, was not majorly disrupted.
Read more about the study here.
07/07/2021 10:28 GMT — Call to share vaccines with poorer nations immediately
A Nature news feature highlights the stark inequities in global vaccinations. While richer countries are increasingly moving toward easing restrictions, poorer nations do not have this luxury. Only 2% of Africa’s 1.3 billion people have received the first dose of a COVID-19 vaccine so far.
This is in stark contrast to the United States, where 67.1% of adults have received a first dose.
Experts call on richer nations to act now to share vaccines. Despite promises, efforts such as the COVAX initiative are behind schedule to deliver much needed vaccine doses to low and middle income countries.
“The inequitable distribution of vaccines has allowed the virus to continue spreading,” Dr. Soumya Swaminathan, the World Health Organization (WHO)’s chief scientist, told Nature. “We need countries with substantial supply to donate 250 million doses for September,” she continued.
A modeling study led by Andrea Taylor from the Duke Global Health Innovation Center in Durham, NC, projects that it will take until 2023 to supply vaccines to all nations.
“Doses shared now will be so much more impactful than doses in six months. We need wealthy countries to send doses immediately,” Taylor said.
Read more here.
07/05/2021 14:09 GMT — Can COVID-19 vaccines affect periods?
Some anecdotal reports suggest that, occasionally, menstruating people experience changes to their periods after a COVID-19 vaccine. According to some of these reports, people may experience heavier, more painful, or longer-than-usual periods following a COVID-19 shot.
Medical News Today has spoken to Dr. Katharine Lee, a postdoctoral research fellow in the Division of Public Health Sciences at the Washington University School of Medicine in St. Louis, MO, and Dr. Kathryn Clancy, an associate professor in the Department of Anthropology at the University of Illinois at Urbana-Champaign to find out more about how these changes might manifest, who might experience them, and why.
We also spoke to two physicians — Dr. Tara Scott and Dr. Kathleen Jordan — and four women who experienced changes to their periods after a COVID-19 vaccine.
“[I]t would have been good to be prepared for [this possibility] ahead of time and for the scientific community to take this impact [of COVID-19 vaccines] seriously, as women do tend to just suffer through it,” one of these women told us.
To find out more, read our Special Feature.
07/02/2021 13:36 GMT — Longer gap between COVID-19 vaccine doses may increase immune response
A new study provides reassurance that a longer gap between the first and second doses of the Oxford-AstraZeneca vaccine will not compromise a person’s immune response. A gap of up to 45 weeks actually led to a stronger immune response compared with the recommended interval.
Read more about the study here.
07/02/2021 12:29 GMT — J&J vaccine protects against delta variant
In a press release, Johnson & Johnson announced that according to recent data, its single-shot vaccine “generated strong, persistent activity against the rapidly spreading delta variant and other highly prevalent SARS-CoV-2 viral variants.” The company also explains that the protection persisted for the full 8 months that researchers have evaluated to date.
“Today’s newly announced studies reinforce the ability of the Johnson & Johnson COVID-19 vaccine to help protect the health of people globally,” says Dr. Paul Stoffels, vice chairman of the Executive Committee and chief scientific officer at Johnson & Johnson.
“We believe that our vaccine offers durable protection against COVID-19 and elicits neutralizing activity against the delta variant,” he continues. “This adds to the robust body of clinical data supporting our single-shot vaccine’s ability to protect against multiple variants of concern.”
07/02/2021 09:41 GMT — Moderna, Pfizer vaccines reduce severity and viral load for those who still contract SARS-CoV-2
A recent study investigated how well the Moderna and Pfizer mRNA vaccines prevented and attenuated COVID-19 in real-world conditions. The authors conclude that they were “highly effective” at preventing infection. Also, those who did contract the virus experienced less severe symptoms and a shorter illness.
The study, which appears in The New England Journal of Medicine, also found that individuals who were vaccinated but contracted the virus had significantly lower viral loads.
According to the authors of the study, “Participants who were partially or fully vaccinated at the time of infection had a 40% lower viral RNA load.”
In total, the research involved 3,975 healthcare personnel, first responders, and other frontline workers. The scientists followed the participants for 17 weeks.
Two doses of an mRNA vaccine were 91% effective against SARS-CoV-2 infection, whether symptomatic or asymptomatic. A single dose of vaccine was 81% effective.
07/01/2021 09:41 GMT — U.K.’s NHS plans winter COVID-19 booster for over 50s
Experts have advised the United Kingdom’s National Health Service (NHS) that 30 million of the U.K.’s most vulnerable should receive a third COVID-19 vaccine dose as winter approaches.
“We want to be on the front foot for COVID-19 booster vaccination to keep the probability of loss of vaccine protection, due to waning immunity or variants, as low as possible — especially over the coming autumn and winter,” explains England’s deputy chief medical officer Prof. Jonathan Van-Tam.
He believes that winter flu is likely to “make a comeback,” so “we will need to ensure protection against flu, as well as maintaining protection against COVID-19.”
The U.K.’s Health and Social Care Secretary, Sajid Javid, says, “Our first COVID-19 vaccination program is restoring freedom in this country, and our booster program will protect this freedom.”
07/01/2021 09:10 GMT — Why are young cancer survivors concerned about COVID-19 vaccination?
A new study raises concerns about vaccine hesitancy among young survivors of cancer in the United States. The authors found that some adolescent and young adult cancer survivors are hesitant to get vaccinated against COVID-19. The results of the study appear in JNCI Cancer Spectrum.
Read MNT’s coverage of the study here.
06/30/2021 09:32 GMT — Moderna COVID-19 vaccine effective against a model of the delta variant
In a new study, not yet peer-reviewed, scientists from Moderna found that antibodies from vaccinated clinical trial volunteers could effectively neutralize a model virus that carries the SARS-CoV-2 spike protein with the delta variant mutations.
The team investigated how well serum from eight trial volunteers could neutralize the model virus, or pseudovirus. They made a number of these pseudoviruses to represent the delta variant and other variants of concern, including the alpha variant, first identified in the United Kingdom, and the beta variant, first identified in South Africa.
While the ability to neutralize the delta variant was lower compared with the alpha variant and the previously dominant variant, the study authors say all of the variants “remained susceptible” to neutralization by antibodies generated in response to the Moderna vaccine.
“As we seek to defeat the pandemic, it is imperative that we are proactive as the virus evolves. We remain committed to studying emerging variants, generating data, and sharing it as it becomes available. These new data are encouraging and reinforce our belief that the Moderna COVID-19 [v]accine should remain protective against newly detected variants,” said Stéphane Bancel, chief executive officer of Moderna, in a press release. “These findings highlight the importance of continuing to vaccinate populations with an effective primary series vaccine.”
Read more about which vaccines work against the delta variant here.
06/29/2021 15:15 GMT — Mixing COVID-19 vaccines is effective, study suggests
Oxford Vaccine Group’s Com-Cov vaccine trial has examined the benefits of mixing different brands of COVID-19 vaccines between the first and the second dose.
Namely, the trial examined the efficacy of two doses of Pfizer-BioNTech, two doses of AstraZeneca, and one of them followed by the other in 850 people aged 50 years and older.
The results revealed that all combinations worked well, triggering an immune response. More specifically, the results suggested that:
AstraZeneca followed by Pfizer triggered more antibodies and T cell responses than Pfizer followed by AstraZeneca. Both AstraZeneca followed by Pfizer and Pfizer followed by AstraZeneca induced more antibodies than two doses of AstraZeneca.Two doses of Pfizer created the highest number of antibodies, and the highest T cell response resulted from AstraZeneca followed by Pfizer.
Read the full story here.
06/29/2021 12:50 GMT — More evidence that Pfizer vaccine offers long-term protection
A new study appearing in the journal Nature suggests that the Pfizer-BioNTech COVID-19 vaccine offers long-lasting protection.
The study, led by Dr. Ali Ellebedy, an immunologist at Washington University, in St. Louis, MO, examined the body’s immune response as it manifests in the so-called germinal centers. Germinal centers are B cell structures in the lymph nodes.
B cells respond to an antigen, or a foreign substance, by making antibodies. The cells mature into specialist cells that, in turn, can create long-term immunity. The study examined these immune reactions in 14 individuals who had received both doses of the Pfizer COVID-19 mRNA vaccine.
The team found that the B cells persisted in the germinal centers in the lymph nodes for almost 4 months after vaccination. Usually, these decline after 4–6 weeks, an immunologist explained to The New York Times.
Studies that track B cell biology in germinal centers over a long period are limited and most are conducted in animals, the authors note. However, these previous studies have found the germinal center B cells to persist for at least 1 year.
The fact that in this study, the reactions to the vaccine continued for almost 4 months is “a very, very good sign,” said Dr. Ellebedy.
Dr. Peter English, a retired consultant in communicable disease control and former chair of The British Medical Association’s Public Health Medicine Committee, cautioned:
“Note that this paper only studies the Pfizer BioNtech vaccine. It does not compare this vaccine with other vaccines, so we do not know if other vaccines are as good, better, or not as good as [the Pfizer vaccine] in these respects.”
06/28/2021 10:42 GMT — The ‘Great Gamble’: The story of CoWIN, India’s vaccination portal
In April 2021, the Indian government inaugurated its online COVID-19 vaccination booking system, called CoWIN.
On the very first day, more than 10 million people signed up in the first 8 hours, leading to a system crash.
Since then, CoWIN has been riddled with technical issues and various glitches, causing concern among the general population and health experts.
“While the website’s user interface was fine, (navigating) it is arduous because one has to keep refreshing the page in order to see updated (vaccine availability) information,” Prof. Ranjini Rao, a marketing communications professor at Commits College in Bengaluru, India, told Medical News Today.
Read more about the controversies surrounding CoWIN in our Special Feature.
06/25/2021 13:30 GMT — Which vaccines are effective against the delta variant?
06/25/2021 09:52 GMT — Delta variant and breakthrough infections in Israel
The delta variant of SARS-CoV-2, first identified in India, is rapidly becoming the dominant variant in many places across the globe.
Breakthrough infections can occur when people have a SARS-CoV-2 infection despite being vaccinated. Israel has recently reported a rise in new infections, believed to be due to the delta variant, despite having high vaccine coverage.
This has led officials to reintroduce the indoor mask mandate starting today at 12:00 p.m., according to Haaretz. On Thursday, there were 227 new cases in the country, the highest number seen since mid-April.
So far, the rate of new hospital admissions with COVID-19 remains low, The New York Times reported yesterday. Among the 729 people who currently have a confirmed SARS-CoV-2 infection, 26 are receiving treatment in a hospital.
This trend is in keeping with data from the United Kingdom. Recent reports from Public Health England indicate that while vaccines are not quite as effective at keeping infections with the delta variant at bay, particularly after the first dose, they are very effective at preventing hospitalization.
Find the latest on how well vaccines work against the delta variant here.
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