Introduction by Croakey: The Omicron variant has now been confirmed in 76 countries, as of 14 December, and the overall risk related to the new variant of concern “remains very high”, according to the latest World Health Organization epidemiological update.
The OzSage group this week urged the Federal Government to bring forward third doses to avoid the likelihood of a major wave of new infections caused by Omicron. This should help to reduce avoidable illness and deaths, and reduce demand for hospital care, they said.
“Based on present information, a third vaccine dose could be given any time from two to six months after the second dose. OzSAGE is concerned that the newly revised five month booster interval will leave too many Australians vulnerable, and be too late to prevent a surge in Omicron in Australia, as is predicted in the UK. Rapidly achieving high third dose coverage is essential for protecting Australians and the health system.”
OzSAGE said that as of 12 December, 19,262,415 Australians were double-vaccinated (75 percent of the population) but only 687,067 (2.7 percent of the population) had received a third dose.
As many Australians embark upon summer holidays and related travel and social interactions, the vaccination workforce faces escalating pressures with the rollout of childhood and booster vaccinations, and the Australian Medical Association warned today that far more support is needed to support the workforce.
In this time of competing political and public health agendas and rapidly changing circumstances, there is a very real danger of mixed messaging that undermines public health responses – as we saw today in NSW.
Meanwhile, public health researcher and Croakey columnist Alison Barrett provides an overview of the latest research on COVID vaccination.
Alison Barrett writes:
COVID-19 vaccination and children
Publication: Evaluation of the BNT162b2 COVID-19 Vaccine in Children 5 to 11 years of age
Walter, EB et al., New England Journal of Medicine, 9 November 2021
(ATAGI) announced their recommendations for the use of Pfizer’s COVID-19 vaccine in children aged 5 to 11 years.
The roll-out is expected to start in the first few weeks of January 2022.
AGATI’s announcement included a statement saying they did not support restricting activities for children in this age group who are not vaccinated or have only had one dose.
Children tend to be less likely to experience severe COVID-19; however, they can develop mild to moderate symptoms, or a rare but serious side effect known as multisystem inflammatory syndrome in children (MIS-C).
More studies and data are required to fully understand the long-term impact of COVID-19 in children, but evidence indicates that some children may be susceptible to long COVID, the term used to describe persistent symptoms of COVID-19 that last for two or more months.
Results from the randomised control trial of Pfizer-BioNTech’s BNT162b2 vaccine in children between 5 and 11 years indicate the vaccine is safe and effective in preventing symptomatic COVID-19 in this age group.
Phase 2 and 3 of the trial included 2,268 children to determine the safety, efficacy (the vaccine’s capacity to prevent disease in controlled conditions) and immune response of the Pfizer vaccine.
Participating children were from the United States, Spain, Finland and Poland, and the study cohort had an average age of eight years.
Children were randomly allocated into either a group that received a placebo of saline solution or a group that received 10 micrograms of the Pfizer vaccine, both administered 21 days apart.
The 10 microgram dose for children was determined in a previous phase of the trial where they found this dose was efficient in producing neutralising antibodies and also safe. It is one-third of the dose administered to adults.
It is interesting to note that ATAGI recommend children in this age group receive their two doses eight weeks apart, differing from the dose in the trials.
ATAGI’s reasons for extending the interval between doses include the potential for improved effectiveness and immune response after the second dose, as seen in adult populations (cited evidence here and here), and decreased risk of myocarditis and pericarditis.
A study in Canada, not yet peer-reviewed, found that rates of myocarditis and pericarditis in people 12 years and older were higher when the interval between vaccine doses was shorter than 30 days. These studies did not include 5 to 11 year olds.
The evaluation of the Pfizer vaccine in the 5 to 11 year old group found that it was 90.7 percent efficacious at preventing symptomatic COVID-19. During the trial, three cases of COVID-19 were reported in the vaccine group, compared to 16 in the placebo group.
Importantly, no cases of severe COVID-19 or multisystem inflammatory syndrome in children were reported during the trial.
Safety data was collected via an electronic diary for seven days after each dose.
The most common reactions for children who received the Pfizer dose were pain at the injection site, which occurred in 74 percent of children after the first dose and 71 percent after the second dose; and fatigue (34% after first dose, 39% after second dose) and headaches (22% after first dose, 28% after second dose).
While chills and fever were not very common, medication to reduce fever was more frequently administered after the second dose than the first.
Reactions were generally mild to moderate and lasted between one and two days.
Severe adverse events were reported in two participants during the trial and both were considered not to be related to the vaccine or placebo. One participant in the placebo group had post-injury abdominal pain and pancreatitis and one participant in the vaccine group reported a fractured arm.
No anaphylaxis, pericarditis or myocarditis was reported in the group that received the Pfizer vaccine.
While the evaluation provides positive results for the safety and efficacy of the Pfizer vaccine, it should be noted that limitations of the study include its small population size and its short-term follow-up.
However, the researchers intend to follow the children in the trial for two years after their first dose for longer-term monitoring of potential cases of COVID-19. Real-world data of its application is also becoming available.
Approximately 4.8 million children in the US have received at least one COVID-19 vaccine dose since they began the vaccine roll-out in 5 to 11-year-olds on 2 November 2021; and 60,000 children in Israel have been vaccinated since their paediatric roll-out began on 22 November 2021.
More information about side effects will become available as more children become vaccinated, but at this stage, no serious side effects have been reported from the Pfizer vaccine in children aged 5 to 11 years old in the US or Israel.
In summary, the authors wrote, “direct benefits of preventing SARS-CoV-2 infection in children include protection against severe disease, hospitalisations, and severe or long-term complications, such as MIS-C. Indirect benefits include the likelihood of reduced transmission in the home and in school settings, including transmission affecting vulnerable persons, and safer in-person learning. Without effective COVID-19 vaccines for this age group, children could potentially become ongoing reservoirs of infection and sources of newly emerging variants.“
Useful information about vaccinating children against COVID-19
Frequently asked questions about COVID-19 vaccination in children: Centers for Disease Control and Prevention, 22 November 2021
Myths and facts about COVID-19 vaccines for children: Centers for Disease Control and Prevention, 22 November 2021
Vaccinating children will help to protect everyone in the community: Associate Professor Margie Danchin, The Age, 11 December 2021
Update on Omicron
Report: Omicron (B.1.1.529) variant evidence check
NSW Government Agency for Clinical Innovation (ACI), 10 December 2021
As at 10 December 2021, 62 countries had reported confirmed cases of the Omicron variant of concern. We are learning more about the variant as it spreads to more countries.
Following is a summary of the evidence published by the NSW Government Agency for Clinical Innovation (ACI) on 10 December.
The Omicron variant was first reported to the World Health Organization (WHO) by South Africa on 24 November 2021, and it was designated a variant of concern by WHO on 26 November 2021.
Preliminary evidence from South Africa indicates the Omicron variant is associated with an increased risk of reinfection with the virus.
It is still not clear if Omicron is more transmissible than other variants; however, preliminary data from South Africa indicates that it is more transmissible than Delta.
It is also unclear if the variant causes more severe disease. While increasing rates of hospitalisation have been reported in South Africa, it is not clear at this stage if this is due to the increased rates of infection or due to severity of disease.
Research is being conducted to determine if current vaccines are effective against Omicron.
Some breakthrough infections, where a vaccinated individual becomes infected with SARS-CoV-2, have been reported in South Africa.
Early evidence from the UK suggests that two doses of Vaxzevria (AstraZeneca) provides no protective effect against symptomatic infection of Omicron, and Pfizer provides little (34 to 37% effectiveness), 15 weeks after the second dose.
In an indication of the value of booster doses, vaccine effectiveness against symptomatic infection of Omicron increased in people who received a third dose after either two doses of Vaxzevria and Pfizer.
As the data in this study is based on small population numbers, it is subject to some uncertainty. More research is underway to determine the effectiveness of three doses of Pfizer and Moderna against Omicron.
Moderna, BioNTech and Johnson & Johnson have started developing vaccines specific to the new variant.
“Current understanding of the Omicron variant from recent data are likely to evolve as more data becomes available,” the WHO stated in their latest technical brief about the new variant of concern.
Melissa Sweet wrote about the new variant and immediate responses in Croakey recently: Two years later, and Omicron is a reminder of how little we’ve learnt.
Research and update on COVID-19 booster doses
Publication: BNT162b2 vaccine booster and mortality due to COVID-19
Arbel, R et al., New England Journal of Medicine, 8 December 2021
On Sunday, the Australian Government Department of Health announced that the interval between the third (booster) dose and second dose of COVID-19 vaccine would be reduced from six to five months.
They also announced that Moderna’s COVID-19 vaccine would be available for Australians’ booster dose, in addition to the already approved Pfizer, regardless of what vaccine was received in the first two doses.
The reduced interval between doses is largely based on evidence from the booster rollout in Israel, where they began administering third (booster) doses of Pfizer to people 50 years or older on 30 July 2021, with the aim of slowing down a resurgence of COVID-19 cases.
“Data from Israel shows boosters supporting reductions in the rate of infection in eligible age groups, severe disease in those aged over 40 years and deaths in those over 60 years,” Minister Greg Hunt said in his announcement.
An analysis of Israeli’s booster rollout found that those who received a third dose of Pfizer during the study period between 6 August and 29 September 2021 had 90 percent lower mortality risk from COVID-19 than those who had not received a third dose (hazard ratio 0.10; 95% confidence interval, 0.07 to 0.14; P<0.001).
Researchers analysed COVID-19-related medical records of 843,208 people who had two doses of Pfizer at least five months earlier, were 50 years or older and not received a booster dose before 6 August 2021 (the study period start date).
To make comparisons, they divided the study population into two groups: those who had received a third dose during the study period (number of people, 758,118) and those who had not (number of people, 85,090).
They also found that when compared to those who had not received a third dose, those who received a third dose were 83 percent less likely to have a confirmed infection from the virus (hazard ratio 0.17 (95% CI, 0.16 to 0.18; P<0.001).
While promising, it is important to note that the average age of the study population was 68.5 years, an older age group that have higher mortality and potentially different health-related behaviours to younger age groups.
The follow-up period was quite short at 54 days, and limited data was available on serious adverse events, if any, following the third dose, so further studies are required to determine safety and long-term effectiveness.
However, early evidence from the UK also supports the effectiveness of a third dose in protecting against symptomatic COVID-19.
Effectiveness of public health measures, including masks
Publication: Effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission and COVID-19 mortality: systematic review and meta-analysis
Talic, S et al., the BMJ, 18 November 2021
Although vaccines are important to minimise illness, hospitalisations and deaths from COVID-19, they do not provide 100 percent protection and it is necessary to maintain a range of public health measures.
As per the Swiss Cheese model of risk reduction, multiple interventions are required to prevent spread of a virus.
Mask wearing is the most effective method of reducing the incidence of the virus, according to a systematic review of evidence about the effectiveness of public health measures in reducing the incidence, transmissibility and mortality from COVID-19.
The review did not assess the effectiveness of vaccines; but analysed the effect of handwashing, school closures, mask wearing, physical distancing, stay at home orders, lockdowns and travel and border restrictions.
Mask wearing resulted in a 53 percent reduction in COVID-19 incidence, and physical distancing resulted in 25 percent reduction.
While the review found that all public health measures reduced incidence and/or transmission of the virus, the included studies were too different to quantitatively measure.
Some limitations should be noted, including the inability to evaluate the impact from different types of masks (reusable, surgical, N95 respirators), and difficulties determining cause when multiple strategies are likely to be implemented at the same time.
However, the review was quite rigorous and comprehensive, and the authors minimised study selection bias by dual screening all records found in the search. The results provide strong evidence of the effectiveness of public health measures, in particular mask wearing and physical distancing, in minimising the impact of COVID-19.
The authors suggest further research is required to understand public adherence to public health measures and the effectiveness of them after sufficient vaccination coverage.
Graphic summary of the systematic review sourced from the BMJ, under Creative Commons License
Some interesting, additional reading
We’re not at endemicity yet: Zhang, S, The Atlantic, 7 December 2021
“No one knows exactly what endemic COVID will look like, but whatever it looks like, this –gestures at the current situation – ain’t it. COVID is not yet endemic. There is little doubt that the coronavirus will get there eventually, when almost everyone has been vaccinated or infected or both, but right now we are still living through a messy and potentially volatile transition period. Cases are ticking up again. A new variant is afoot. The challenge ahead is figuring out how to manage the transition to endemicity, however long it takes.”
Even healthcare workers with Long COVID are being dismissed: Yong, E, The Atlantic, 24 November 2021
“Before she caught COVID-19 at a wedding in March 2020, the physician associate spent her days diagnosing and treating people; after she was infected, she turned to her own colleagues for that same care. “At first,” she told me, “I felt a kinship with them.” But when her tests started coming back negative, her doctors began telling her that her symptoms –daily migraines, unrelenting vertigo, tinnitus, severe crashes after mild activity – were just in her head.”
On entering Australia’s third year with COVID-19: Duckett, SJ & Sutton, B, The Medical Journal of Australia, 15 November 2021
“We cannot let complacency encumber how we live with the virus: vigilance and a planned recovery are essential.”
Plan B shows Britain is still chasing COVID. Here’s how we can get ahead of it: Sridhar, D, The Guardian, 9 December 2021
“And while we focus on Omicron now, we have to be thinking ahead to what the next version of COVID-19 could look like this spring, and how we get ahead of this virus, instead of always trying to catch up. This involves managing COVID-19 using vaccines, testing, masks and clear messages to the public on where we are and why. And having someone in charge whom we can trust to be honest and public-oriented.”
Resources
How to engage the arts to build COVID-19 vaccine confidence: Centers for Disease Control and Prevention, November 2021. Guides and resources for using art and creative approaches to increase confidence in COVID-19 vaccines.
Zoe COVID study: Led by Professor Tim Spector from King’s College London, the Zoe COVID study was launched in March 2020 to collect COVID-19 related data in the UK, via an app.
A wealth of evidence-based information is available on their website here, including a blog post about pregnancy, fertility and COVID-19 and a webinar about long COVID.
Coronacast: Swan, N & Taylor, T, ABC. Catch up on the latest Coronacast episodes with Dr Norman Swan and Tegan Taylor, including discussions about Omicron, third doses of COVID-19 vaccines, and travel bubbles.
You’ve got questions: Government of Western Australia, 2021. As part of the ‘Roll up WA’ COVID-19 vaccine campaign, Dr Karl and a panel of experts answer common questions about the vaccinations, including concerns about long-term side effects from the vaccines.
From Twitter
Alison Barrett is a Masters by Research candidate and research assistant at University of South Australia, with interests in public health, rural health and health inequities. Follow on Twitter: @AlisonSBarrett. Croakey thanks her for providing this column as a probono service to our readers.
See previous editions of the COVID wrap.
COVID-19 Twitter lists
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