Vaccine monitoring crucial as SARS-CoV-2 variants continue to evolve
Researchers at the Francis Crick Institute and the National Institute for Health and Care Research Biomedical Research Centre at UCLH have highlighted the importance of continued surveillance of emerging SARS-CoV-2 variants and vaccine performance as the virus continues to evolve.
Published today as a research letter in The Lancet, their study compared the newer monovalent COVID vaccine, which specifically targets the XBB variant of Omicron (as recommended by the World Health Organisation), with older bivalent vaccines containing a mix of an Omicron variant and the original strain of COVID-19, which the UK deployed in Autumn 2023 before turning to monovalent vaccines1.
The researchers found that both vaccines generated neutralising antibodies against the most recent strain of Omicron, BA.2.86. However, the new monovalent vaccine generated higher levels of antibodies against a range of other Omicron variants.
The team collected blood and nasal mucosal samples both before and after a fifth dose vaccination from 71 participants of the Legacy study, a research collaboration between the Crick and the NIHR University College London Hospitals Biomedical Research Centre. They compared the antibody levels before and after vaccination.
All 36 participants who received the bivalent vaccine and 17 who received the monovalent vaccine had boosted levels of antibodies against all variants tested, including the newest strain BA.2.86, which caused a wave of infection this winter. But those with the newer monovalent vaccine had 3.5x higher levels of antibodies against the XBB and BQ.1.1 strains after their booster vaccination.
Since the Omicron virus is highly transmissible and the virus replicates in the nose and throat, the researchers tested the levels of antibodies in the participants’ nasal cavity.
They found that the monovalent vaccine increased their ability to produce mucosal antibodies against most of the tested variants, whereas the bivalent vaccine didn’t provide a significant boost.
Neither vaccine increased neutralising antibody levels in the nasal cavity against the newest variant, BA.2.86, suggesting that current vaccines may be less likely to stop transmission or prevent asymptomatic or mild illness, while still protecting against severe disease.
This highlights the importance of careful vaccine updates and continuing to complement a vaccination programme with the development of antibody drugs that work against all variants, as some more vulnerable people don’t respond well to vaccines.
Emma Wall, Senior Clinical Research Fellow at the Crick and Consultant in Infectious Diseases at UCLH, said: “The UK’s strategy to deploy stocks of older vaccines paid off last year, as both vaccines provided equal protection against the newest strain. However, ongoing monitoring is needed, as the virus is continuing to evolve, so vaccine-induced antibodies might not work so well in the future. In the long run, vaccines that are effective against all new variants and can block COVID-19 being transmitted from person to person are needed.”
David LV Bauer, Group Leader of the RNA Virus Replication Laboratory at the Crick, said: “The situation this winter could have been different if the newly emerged BA.2.86 and JN.1 variants were substantially distinct from older Omicron variants, but fortunately this wasn’t the case.
“Most new variants arise quicker than most clinical trials can produce data. But laboratory analysis can provide a detailed picture very quickly. Continued surveillance will help us stay on top of viral evolution.”
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For further information, contact: press@crick.ac.uk or +44 (0)20 3796 5252
Notes to Editors
Reference: Shawe-Taylor, M and Greenwood, D. et al. (2024). Divergent performance of vaccines in the UK autumn 2023 COVID booster campaign. The Lancet. 10.1016/S0140-6736(24)00316-7.
- In Autumn 2023, the UK deployed stocks of ‘bivalent’ vaccines, which encode the Spike protein of the Omicron BA.5 variant that circulated in 2022, and the original 2019 strain of COVID-19, before turning to newer ‘monovalent’ vaccines, which encode the Spike protein of the XBB.1.5 Omicron variant that circulated in early 2023.
The Francis Crick Institute is a biomedical discovery institute dedicated to understanding the fundamental biology underlying health and disease. Its work is helping to understand why disease develops and to translate discoveries into new ways to prevent, diagnose and treat illnesses such as cancer, heart disease, stroke, infections, and neurodegenerative diseases.
An independent organisation, its founding partners are the Medical Research Council (MRC), Cancer Research UK, Wellcome, UCL (University College London), Imperial College London and King’s College London.
The Crick was formed in 2015, and in 2016 it moved into a brand new state-of-the-art building in central London which brings together 1500 scientists and support staff working collaboratively across disciplines, making it the biggest biomedical research facility under a single roof in Europe.
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About UCLH
UCLH (University College London Hospitals NHS Foundation Trust) provides first-class acute and specialist services in five hospitals in Central London including the National Hospital for Neurology and Neurosurgery at Queen Square which is the largest hospital of its kind in the UK. UCLH is committed to education and research and forms part of UCLPartners which in March 2009 was officially designated as one of the UK's first academic health science centres by the Department of Health. UCLH works closely with UCL, translating research into treatments for patients. For more information visit www.uclh.nhs.uk. We are also on Facebook (UCLHNHS), Twitter (@uclh), Youtube (UCLHvideo) and Instagram (@uclh).
About the NIHR
The National Institute for Health and Care Research (NIHR) is the nation's largest funder of health and care research. The NIHR:
- Funds, supports and delivers high quality research that benefits the NHS, public health and social care
- Engages and involves patients, carers and the public in order to improve the reach, quality and impact of research
- Attracts, trains and supports the best researchers to tackle the complex health and care challenges of the future
- Invests in world-class infrastructure and a skilled delivery workforce to translate discoveries into improved treatments and services
- Partners with other public funders, charities and industry to maximise the value of research to patients and the economy
The NIHR was established in 2006 to improve the health and wealth of the nation through research, and is funded by the Department of Health and Social Care. In addition to its national role, the NIHR supports applied health research for the direct and primary benefit of people in low- and middle-income countries, using UK aid from the UK government.
JOURNAL
The Lancet
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Divergent performance of vaccines in the UK autumn 2023 COVID booster campaign.
ARTICLE PUBLICATION DATE
11-Mar-2024
COVID-19 had greater impact on life expectancy than previously known, but child mortality rates continued to decline during the pandemic
A new study published in The Lancet reveals never-before-seen details about staggeringly high mortality from the COVID-19 pandemic within and across countries. Places such as Mexico City, Peru, and Bolivia had some of the largest drops in life expectancy from 2019 to 2021. The research, which presents updated estimates from the Global Burden of Disease Study (GBD) 2021, provides the most comprehensive look at the pandemic’s toll on human health to date, indicating that global life expectancy dropped by 1.6 years from 2019 to 2021, a sharp reversal from past increases. Among GBD’s other key findings, child mortality continued to drop amid the COVID-19 pandemic, with half a million fewer deaths among children under 5 in 2021 compared to 2019. Mortality rates among children under 5 decreased by 7% from 2019 to 2021.
“For adults worldwide, the COVID-19 pandemic has had a more profound impact than any event seen in half a century, including conflicts and natural disasters,” says co-first author Dr. Austin E. Schumacher, Acting Assistant Professor of Health Metrics Sciences at the Institute for Health Metrics and Evaluation (IHME) at the University of Washington. “Life expectancy declined in 84% of countries and territories during this pandemic, demonstrating the devastating potential impacts of novel pathogens.”
Researchers from IHME identified high mortality during the COVID-19 pandemic in places that were previously less recognized and/or reported. For example, the study reveals that after accounting for the age of the population, countries such as Jordan and Nicaragua had high excess mortality due to the COVID-19 pandemic that was not apparent in previous all-age excess mortality estimates. In analyzing subnational locations not previously investigated, the South African provinces of KwaZulu-Natal and Limpopo had among the highest age-adjusted excess mortality rates and largest life expectancy declines during the pandemic in the world. Conversely, the places with some of the lowest age-adjusted excess mortality from the pandemic during this period included Barbados, New Zealand, and Antigua and Barbuda.
During the COVID-19 pandemic, mortality among older people worldwide rose in ways unseen in the previous 70 years. While the pandemic was devastating, killing approximately 16 million people around the globe in 2020 and 2021 combined, it did not completely erase historic progress – life expectancy at birth rose by nearly 23 years between 1950 and 2021.
GBD 2021 analyzes past and current demographic trends at global, regional, national, and subnational levels. The study provides globally comparable measures of excess mortality and is one of the first studies to fully evaluate demographic trends in the context of the first two years of the COVID-19 pandemic. In estimating excess deaths due to the pandemic, the authors accounted for deaths from the virus that causes COVID-19, SARS-CoV-2, as well as deaths associated with indirect effects of the pandemic, such as delays in seeking health care.
Employing innovative methods to measure mortality, excess mortality from the COVID-19 pandemic, life expectancy, and population, the study authors estimate that the pandemic caused global mortality to jump among people over age 15, rising by 22% for males and 17% for females from 2019 to 2021.
GBD 2021 goes beyond assessing the impact of the first two years of the COVID-19 pandemic. As the authors note, it also offers “implications for the future of health-care systems, economies, and societies and ... a valuable foundation for policy evaluation, development, and implementation around the world.”
GBD 2021 indicates that, despite early warnings that COVID-19 could threaten the gains that the world had made in saving children’s lives, these improvements continued during the pandemic, albeit at a slower pace. Still, stark differences in child mortality persist between regions. In 2021, one out of every four children who died worldwide lived in South Asia, while two out of every four children who died lived in sub-Saharan Africa.
“Our study suggests that, even after taking stock of the terrible loss of lives the world experienced due to the pandemic, we have made incredible progress over 72 years since 1950, with child mortality continuing to drop globally,” said co-first author Dr. Hmwe Hmwe Kyu, Associate Professor of Health Metrics Sciences at IHME at the University of Washington. “Now, continuing to build on our successes, while preparing for the next pandemic and addressing the vast disparities in health across countries, should be our greatest focuses.”
The GBD 2021 study also assessed population trends. Beginning in 2017, the rate of global population growth began to drop following years of stagnation. Then, during the COVID-19 pandemic, these declines accelerated. As of 2021, 56 countries have reached peak population. Now, these countries are seeing their populations shrink. However, rapid population growth has continued in many lower-income countries. In addition, populations around the world are aging. Between 2000 and 2021, the number of people who were 65 and older grew faster than the number of people under age 15 in 188 countries and territories.
“Slowing population growth and aging populations, along with the concentration of future population growth shifting to poorer locations with worse health outcomes, will bring about unprecedented social, economic, and political challenges, such as labor shortages in areas where younger populations are shrinking and resource scarcity in places where population size continues to expand rapidly,” says Dr. Schumacher. “This is worth restating, as these issues will require significant policy forethought to address in the affected regions. As one example, nations around the world will need to cooperate on voluntary emigration, for which one source of useful guidance is the UN’s Global Compact for Safe, Orderly and Regular Migration.”
For interview requests, journalists may contact media@healthdata.org. For full study results, including the paper and related tables, finalized PDFs are available at https://bit.ly/3STDWaM, embargoed until 23:30 UK, 7:30 p.m. ET on March 11, 2024. The post-embargo link for the paper is https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(24)00476-8/fulltext. An infographic summarizing the study’s findings can be found at https://bit.ly/3T7Hm9V.
About the Institute for Health Metrics and Evaluation
The Institute for Health Metrics and Evaluation (IHME) is an independent research organization at the University of Washington (UW). Its mission is to deliver to the world timely, relevant, and scientifically valid evidence to improve health policy and practice. IHME carries out its mission through a range of projects within different research areas including the Global Burden of Diseases (GBD), Injuries, and Risk Factors; Future Health Scenarios; Cost Effectiveness and Efficiency; Resource Tracking; and Impact Evaluations.
IHME is committed to providing the evidence base necessary to help solve the world’s most important health problems. This requires creativity and innovation, which are cultivated by an inclusive, diverse, and equitable environment that respects and appreciates differences, embraces collaboration, and invites the voices of all IHME team members.
About the Global Burden of Disease Study
The Global Burden of Disease Study (GBD) is the largest and most comprehensive effort to quantify health loss across places and over time. It draws on the work of more than 11,000 collaborators across more than 160 countries and territories. GBD 2021 — the newly published most recent round of GBD results — includes more than 607 billion estimates of 371 diseases and injuries and 88 risk factors in 204 countries and territories. The Institute for Health Metrics and Evaluation coordinates the study.
JOURNAL
The Lancet
ARTICLE PUBLICATION DATE
11-Mar-2024
