Tag: Pfizer

Six Different Booster Vaccines Found to be Safe and Effective

Image by Ivan Diaz on Unsplash

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!

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. 

Pfizer’s Paxlovid Could Deliver Knockout Blow to COVID

Source: Pixabay CC0

Pharmaceutical giant Pfizer announced today that Paxlovid, its investigational novel COVID oral antiviral candidate, significantly reduced hospitalisation and death, based on an interim analysis of its phase II/III clinical trials showing an 89% reduction of risk of hospitalisation or death due to COVID. 

The phase II/III EPIC-HR (Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients) randomised, double-blind study of non-hospitalised adult patients with COVID, who are at high risk of progressing to severe illness. The scheduled interim analysis showed an 89% reduction in risk of COVID-related hospitalisation or all-cause mortality compared to placebo in patients treated within three days of symptom onset (primary endpoint). Only 0.8% of patients who received Paxlovid were hospitalised through Day 28 with zero deaths, compared to 7.0% of patients who received placebo and were hospitalised or died. Similar reductions in COVID-related hospitalisation or mortality were seen in patients treated within five days of symptom onset; 1.0% of patients in the intervention arm were hospitalised through Day 28 with zero deaths, compared to 6.7% of placebo arm patients. In the overall study population through Day 28, no deaths were reported in intervention arm patients as compared to 10 (1.6%) deaths in placebo arm patients.

The results show such an overwhelming effectiveness that Pfizer, in consultation with the US Food and Drug Administration (FDA), will cease further enrollment into the study and will apply for Emergency Use Authorization (EUA) as soon as possible.

If it gets the green light, Pfizer’s Paxlovid, would be the first oral antiviral of its kind, a specifically designed SARS-CoV-2-3CL protease inhibitor. PF-07321332 inhibits viral replication at the proteolysis stage, before viral RNA replication. Co-administration with a low dose of ritonavir helps slow the metabolism of PF-07321332 in order for it to remain active in the body for longer at higher concentrations. It has shown effectiveness against multiple variants, and could have broad general effectiveness against coronaviruses.

“All of us at Pfizer are incredibly proud of our scientists, who designed and developed this molecule, working with the utmost urgency to help lessen the impact of this devastating disease on patients and their communities,” said Mikael Dolsten, MD, PhD, Chief Scientific Officer and President, Worldwide Research, Development and Medical of Pfizer. “We’re thankful to all of the patients, investigators, and sites around the world who participated in this clinical trial, all with the common goal of bringing forth a breakthrough oral therapy to help combat COVID.”

The review of safety data included a larger cohort of 1881 patients in EPIC-HR, whose data were available at the time of the analysis. Adverse events were comparable between paxlovid (19%) and placebo (21%), which were mostly mild.

Pfizer kicked off the EPIC-HR study in July 2021 after positive results from Phase I clinical trials, followed in August by the Phase II/III EPIC-SR (Evaluation of Protease Inhibition for COVID-19 in Standard-Risk Patients), to evaluate efficacy and safety in patients with a confirmed diagnosis of SARS-CoV-2 infection who are at standard (low) risk. This trial includes a cohort of vaccinated at-risk patients who have an acute breakthrough COVID infection. A further trial is investigating prophylaxis among household members of patients with a COVID infection. 

Source: Pfizer

No Finding of Early Miscarriage Risk from COVID Vaccinations

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A new study has found no association between COVID vaccinations and risk of first-trimester miscarriages, providing further evidence of the safety of COVID vaccination during pregnancy. The findings were published in the New England Journal of Medicine.

Study co-author Dr Deshayne Fell said, “The study analysed several national health registries in Norway to compare the proportion of vaccinated women who experienced a miscarriage during the first trimester and women who were still pregnant at the end of the first trimester.”  Dr Fell, is Associate Professor in the School of Epidemiology and Public Health in the University of Ottawa’s Faculty of Medicine and a Scientist at the Children’s Hospital of Eastern Ontario (CHEO) Research Institute.

“Our study found no evidence of an increased risk for early pregnancy loss after COVID vaccination and adds to the findings from other reports supporting COVID vaccination during pregnancy,” the study authors wrote. 

“The findings are reassuring for women who were vaccinated early in pregnancy and support the growing evidence that COVID vaccination during pregnancy is safe.”

Dr Fell and colleagues found no relationship between the type of vaccine received and miscarriage. In Norway, the vaccines used included Pfizer, Moderna and AstraZeneca.

“It is important that pregnant women are vaccinated since they have a higher risk of hospitalisations and COVID-complications, and their infants are at higher risk of being born too early. Also, vaccination during pregnancy is likely to provide protection to the newborn infant against COVID infection in the first months after birth,” the study authors stressed.

Source: University of Ottawa

Pfizer Vaccine Fully Approved in US

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On Monday, the US Food and Drug administration approved the Pfizer/BioNTech COVID vaccine, the first vaccine against the novel coronavirus to receive full approval.

The vaccine, which will be marketed as Comirnaty, can be used for individuals ages 16 and older for COVID prevention. However, the vaccine is still under emergency use authorisation (EUA) for adolescents ages 12-15, the agency said.

FDA Acting Commissioner, Janet Woodcock, MD, said in a statement: “While this and other vaccines have met the FDA’s rigorous, scientific standards for emergency use authorisation, as the first FDA-approved COVID vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product.”

At a media briefing, Peter Marks, MD, PhD, the director for the Center for Biologics Evaluation and Research at FDA, detailed the meticulous process used for conducting a review of a biologics license application for full approval, including invidivual analysis of adverse events.

Since 11 December, 2020, the vaccine has been under an EUA for individuals ages 16 and older. Evidence for the full approval comes from expanded phase III trial safety and efficacy data released by the manufacturer this April. An analysis of 927 confirmed cases in the trial’s 44 000 participants found that 7 days after the second dose, Comirnaty had a 91.3% efficacy against symptomatic COVID through 6 months.

More than half of the participants had over 4 months of safety data, including 12 000 people who were followed up through 6 months. Injection site pain, fatigue, headache, muscle or joint pain, and fever were the most common adverse events. A slight increase in risk for myocarditis and pericarditis up to 7 days after the second dose was noted, particularly in males under 40 (peaking in ages 12-17), but symptoms resolved completely.

Trial data was collected before the Delta variant became the dominant strain in the US, Dr Marks noted, Israeli “real world” suggest the vaccine still retains effectiveness but wanes. This is something the agency will follow. 

Former FDA commissioner Dr. Mark McClellan, who now directs the Duke-Margolis Center for Health Policy, spoke to the media about the approval, saying surveys showed that it will help sway vaccine holdouts.

“I do think it will make a difference. Maybe not a large number of people running out and getting a vaccine today. At this point we’ve got a little bit over 70 percent of Americans who are eligible for the vaccine have gotten at least one dose. That’s about 87 million Americans who are eligible who haven’t. Out of those, according to some recent surveys, about 30 percent say the full approval of the Pfizer vaccine would make a difference in their decisions.”

Source: MedPage Today

Department of Health COVID Vaccine Rollout Phase 2 Outlined

The Department of Health’s COVID vaccine rollout has been fleshed out in a presentation, including details on how the vaccines will be distributed, and the jobs earmarked for the shots.

A presentation from the department indicates that the government has secured around 51 million vaccine doses, with 20 million from Pfizer and 30 million from Johnson & Johnson (J&J). However, it is unclear how the current pause in J&J administration in South Africa due to concerns about rare blood clots will affect immunisation schedules.

However, health minister Dr Zweli Mkhize announced that South Africa has secured a further 10 million Pfizer vaccines.

“We can now guarantee that the number of people that will be vaccinated with Pfizer has increased from 10 to 15 million,” he said.

With the 30 million of the single-dose shots from J&J, the current planned rollout will cover about 45 million South Africans.

Dr Mkhize said that both the Pfizer and J&J agreements cost around $10 (R145) per vaccine, with non-refundable clauses.

“The agreements state that down-payments that have been made in advance by the department shall not be refundable by the manufacturer to us in any circumstances. This is another onerous term that we had to settle for,” Dr Mkhize told the committee.

Meanwhile, government was sent an email from J&J, which stated that the company will not sign off the 20 million doses until they receive a letter from the Trade, Industry and Competition Minister, expressing support for the local investment that they made in Aspen Pharmacare.

“We’ve been taken aback by this, as there are clauses in the agreement that express this support and acknowledge that this production will not just be limited to South Africa and the continent, but also targeted for the global market,” said Dr Mkhize.

The department indicated that the Pfizer vaccine will likely go to major metropolitans due to its larger pack size and refrigeration requirements, while the J&J vaccine with its less stringent refrigeration needs would be allocated to rural areas.

South Africa’s Phase 2 of the vaccine rollout is planned to begin in May and run until October, with essential workers over 40 and the elderly to be targeted in the programme. This is to include a focus on old age homes and care facilities, plus identifying those with co-morbidities.

The department provided an overview of occupations covered under the vaccine rollout, to include, among others, the police, army, social and municipal workers, and faith and traditional leaders. Private sectors could include mining, retail, transport, and manufacturing.

Source: BusinessTech

South African Variant Escapes Pfizer Vaccine More Easily

The South African variant escapes protection of the Pfizer/BioNTech vaccine better than other forms of the virus, Israeli experts said Sunday.

The study by Tel Aviv University and Clalit Health Services, Israel’s largest healthcare provider, compared patients with COVID, 400 unvaccinated patients to 400 partially or fully vaccinated ones.

Less than one percent of COVID cases in Israel were due to the South African variant. However, among the 150 people who were fully vaccinated yet had developed COVID, “the prevalence rate [of the B.1.351 variant] was eight times higher than the rate in the unvaccinated [individuals],” the authors wrote.

“This means that the Pfizer-BioNtech vaccine, though highly protective, probably does not provide the same level of protection against the South African (B.1.351) variant of the coronavirus,” the authors added.

“The South African variant is able, to some extent, to break through the vaccine’s protection,” said professor Adi Stern of Tel Aviv University’s Shmunis School of Biomedicine and Cancer Research, one of the study’s authors.

Prof Stern said that the study did not assess whether the eight people infected with the South African developed severe COVID.
“Since we found a very small number of vaccinees infected with B.1.351, it is statistically meaningless to report disease outcomes,” he said.

The possibility of reduced protection was already hinted at in two studies conducted by principal vaccine manufacturers Pfizer/BioNTech and Moderna, showing that the presence of antibodies after vaccination was less pronounced in people exposed to the B.1.351 variant. This marked the first real-world assessment of B.1.351’s ability to bypass a vaccine.

Israel’s vaccination campaign has seen 5.3 million people receive a first dose, while 4.9 million, or 53 percent of the population, have had two shots. 

Clalit’s earlier study on 1.2 million Israelis found that the Pfizer/BioNTech jab gave 94 percent protection against COVID.

Israel has eased many of its restrictions since its vaccine rollout, but various measures remain in place including mask-wearing and a “green passport” system that allows vaccinated people access to certain locations. With cases down 97% since January, Israel may have achieved “herd immunity”, according to Eran Segal, a computational biologist at the Weizmann Institute of Science.

Ran Balicer of Clalit said inoculations, plus mask-wearing and other safety measures had likely helped contain the B.1.351 variant, despite its apparent ability to break through the Pfizer/BioNTech vaccine.

A combination of all these factors “are most likely… preventing the virus strains, including the South African one, from spreading” significantly in Israel, he said.

“As we taper down the non-pharmaceutical interventions, we must do so gradually to ensure we do not cross a threshold that would enable these variants to spread.”

Source: Medical Xpress

Why It’s So Hard to Compare Vaccines

While the world is looking to vaccinations to end the COVID pandemic, a MedPage Today article explains that even with vaccines that have high efficacy, ending transmission is not guaranteed, and there are a lot of differences between simple figures like 94% for Pfizer and 95% for Moderna vaccines.

Firstly, asymptomatic cases are not tracked, simply because assembling tens of thousands of people for a clinical trial is a monumental logistic task, and in the current pandemic, a race against time.

Internist Jeffrey Carson, MD, who managed the Johnson & Johnson COVID vaccine trial’s site at Rutgers University in New Jersey, explained to MedPage Today that it would be difficult but not impossible to create a vaccine trial that provided rapid data about asymptomatic cases.

“You might have people swab themselves every couple days, or every week. You’ll be picking up a lot of disease that way, and you’ll be able to see if the vaccine prevents asymptomatic disease,” Dr Carson said. The current Novavax trial, for example, only asks participants to test themselves for COVID with provided swabs if they believe they are developing symptoms. The Novavax vaccine had also prompted alarm as it was only 49.4% effective against the B501Y.V2 variant, its efficacy reduced by the low rate of protection for HIV positive participants.

The New York Times explained that efficacy is merely how well a vaccine did in a clinical trial, effectiveness is how well it performs in the real world.
Vaccine statistics are difficult even for medical experts to grasp. An infectious diseases expert wrote in a letter to the Lancet explaining that they had misunderstood what 94% to 95% efficacy means for Moderna and Pfizer vaccines and asymptomatic spread.

“It does not mean that 95% of people are protected from disease with the vaccine — a general misconception of vaccine protection.” Instead, it “means that in a population such as the one enrolled in the trials, with a cumulated COVID-19 attack rate over a period of 3 months of about 1% without a vaccine, we would expect roughly 0.05% of vaccinated people would get diseased [with symptomatic infections]. … Accurate description of effects is not hair-splitting; it is much-needed exactness to avoid adding confusion to an extraordinarily complicated and tense scientific and societal debate around COVID-19 vaccines.”

A further problem for scientists is that viral diseases can spread to people unaware that they are infected, something they are still working on understanding. “It makes a lot of sense for survival of the invaders, if you think about it. Humans who feel unwell are not going out to meet up with others, but ones who feel fine will continue along with their daily schedules, allowing the infection to spread,” Bryn Boslett, MD, an infectious disease physician at the University of California San Francisco, told MedPage Today.

Regardless of how well vaccines interrupt the transmission of COVID, it’s important that mask-wearing, social distancing and disinfecting habits are maintained.

“One major worry going forward is that vaccinated people will change their behaviour and stop taking COVID-19 precautions,” Dr Boslett said. “It’s very tempting to do so, very understandable. However, the stars are not yet aligned for us to go back to ‘normal.’ There is still a lot of COVID-19, and most of us are still vulnerable. We need to continue to focus on behavior to reduce new cases of COVID-19.”

Source: MedPage Today

Real-world Results for Pfizer Vaccine Match Trials

Encouraging results have been reported from Israel, where the real-world efficacy of the Pfizer vaccine closely matches that seen in clinical trials.

Israel has engaged in the world’s most aggressive COVID immunisation schedule, with some 30% of its population vaccinated by late January with at least one dose.

Israeli health fund Clalit matched 600 000 vaccinated individuals to an equal number of unvaccinated individuals. Those who were vaccinated experienced a similar rate of positive COVID tests as was observed in clinical trial data, equating to a 94% effectiveness. Crucially, almost no severe cases of COVID were observed in vaccinated individuals. This pattern was also seen in the over-70s age group, which is generally underrepresented in trials.

Public health doctor Prof Hagai Levine said that high vaccination coverage of the most susceptible groups was key. However, he said that he could not give an answer as to what number needed to be vaccinated before containment measures could be eased. 

“We still don’t know what the impact is on transmission,” he said. But he added that “the vaccine is useful for personal protection”.

The greatest drop in cases was seen in the over 60s age group, and in areas which had been vaccinated, indicating that this was not the result of lockdown. However, many people still remain unvaccinated, resulting in tens of thousands of cases. Prof Segal noted that the fall in cases was not as rapid as had been hoped, due to the B.1.1.7 or UK strain becoming dominant in Israel.

“We still have to exit our lockdown very cautiously,” he warned, or else hospitalisations would spike again.

The fact that the same rate was observed in clinical trials is important news for other countries, which are watching to see the effects of Israel’s vaccination programme.

Source: BBC News

Pfizer Vaccine 90% Effective After a Single Dose

A study from the University of East Anglia (UEA) reported that the Pfizer vaccine provides “very high” protection after a single dose.

The researchers drew on Israeli data, where the vaccine had been widely administered, and found that the vaccine was 90% effective at 21 days after the initial dose. This supports the plan that the UK and other nations have of delaying a second dose to achieve maximum coverage. However, they also noted that infection rates increased eight days after the first dose, which they attribute to people becoming less cautious as a result of the vaccination. The study is available on the medRxiv preprint server, and has not been peer reviewed, as it is a rapid response to the ongoing COVID pandemic.

Lead researcher and COVID expert Prof Paul Hunter, from UEA’s Norwich Medical School, said: “A second dose of the Pfizer vaccine would normally be given 21 days or more after the first to top up and lengthen the effect of the first dose.

“But here in the UK, the decision was made to delay the timing of the second injection until 12 weeks after the first.

“The logic behind this is to protect more people sooner and so reduce the total number of severe infections, hospitalisations, and deaths.

“But this decision caused criticism from some quarters due in part to a belief that a single injection may not give adequate immunity.”

Prof Hunter explains the motivation for the study was previous flawed research on the Pfizer vaccine, also using Israeli data. But the study did not consider effectiveness past day 18.

The researchers observed that case incidence rose up til day eight by which time it had doubled, then fell. Prof Hunter said: “We found that the vaccine effectiveness was still pretty much zero until about 14 days after people were vaccinated. But then after day 14 immunity rose gradually day by day to about 90 percent at day 21 and then didn’t improve any further. All the observed improvement was before any second injection.

“This shows that a single dose of vaccine is highly protective, although it can take up to 21 days to achieve this.”

Although the vaccine’s effectiveness beyond this is not known, it still supports the UK’s decision to space out vaccine doses, Prof Hunter concluded.

Source: Medical Xpress

Journal information: “Estimating the effectiveness of the Pfizer COVID-19 BNT162b2 vaccine after a single dose. A reanalysis of a study of ‘real-world’ vaccination outcomes from Israel” is published on the medRxiv pre-print server: www.medrxiv.org/content/10.110 … 021.02.01.21250957v1