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COVID-19
SAGE reviewed the latest epidemiological data on COVID-19 during the Omicron era, including the disease burden and post-COVID conditions, across population groups.
Evidence on the status of vaccine use globally and the safety, effectiveness and cost–effectiveness of currently available vaccines was also reviewed.
The global burden of severe COVID-19 has declined compared with earlier phases during the pandemic, largely due to widespread population immunity through vaccination and prior infection.
Nevertheless, COVID-19 continues to cause morbidity and mortality, particularly among older adults, individuals with comorbidities and people who are immunocompromised.
In terms of post-COVID-19 conditions, persistent symptoms following acute infection have been documented in both adults and children, although estimates of prevalence vary considerably across studies owing to differences in case definitions and study methods.
Vaccination may contribute to reducing the risk of post-COVID-19 conditions, primarily through prevention of severe disease.
In terms of the burden of COVID-19 during pregnancy and infancy in the Omicron era, the risk of severe disease and adverse maternal and fetal outcomes was lower than during the pandemic.
However, people who are pregnant remain at higher risk of severe disease in the Omicron era compared with those of a similar age who are not pregnant.
Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy has been associated with an increased risk of adverse maternal outcomes (e.g. intensive care unit admission) and pregnancy outcomes (e.g. preterm birth).
Data on infants infected with SARS-CoV-2, which are mainly from a few high-income settings, indicate that infants aged under 6 months may experience higher hospitalization rates than older children, although the frequency of severe outcomes is low and varies within these settings.
The currently available mRNA and protein subunit COVID-19 vaccines have an acceptable safety profile across age groups and risk categories, based on 5 years of accumulated COVID-19 vaccine safety data from clinical trials, post-marketing pharmacovigilance systems, surveillance platforms, post-authorization studies and international regulatory reviews.
Serious adverse events remain rare relative to the number of doses administered globally (>13 billion); also, most reported adverse events are mild or moderate and transient, typically resolving within a few days.
A limited number of rare, platform-specific adverse events have been identified, including thrombosis with thrombocytopenia syndrome (TTS) associated with adenovirus vector vaccines that are no longer being manufactured, and myocarditis/pericarditis associated with mRNA and protein vaccines.
However, myocarditis and pericarditis associated with the currently available mRNA and protein vaccines remain uncommon, and have a milder course than post-COVID or conventional myocarditis; hence, the overall benefit–risk balance continues to favour vaccination, particularly among populations at increased risk of serious COVID-19 outcomes.
Safety following repeated doses, including revaccination with variant-adapted vaccines, remains reassuring, with no new safety signals identified.{24}
Real-world evidence consistently shows that the vaccines are effective in reducing COVID-19 associated severe disease and death.
Vaccines adapted to Omicron lineages continue to provide meaningful protection against severe outcomes.
Routine periodic COVID-19 vaccine doses help to sustain protection, despite the relatively rapid waning of protection against infection and limited protection against symptomatic disease beyond 6 months.
Updated evidence on COVID-19 vaccination during pregnancy from observational studies, pregnancy registries, and surveillance systems across multiple countries has not identified safety concerns.
Currently it shows no increased risk of adverse maternal or pregnancy-related outcomes, including miscarriage, stillbirth, preterm birth or adverse outcomes in infants born to people vaccinated during pregnancy.
Vaccination during pregnancy is safe and it provides protection to the pregnant individual, against COVID-19 associated adverse pregnancy outcomes, and to infants aged under 6 months through maternal antibody transfer.
Cost–effectiveness analyses of COVID-19 vaccination consistently show that programmes targeting populations at high risk of severe outcomes (e.g. older adults or individuals with underlying health conditions) are generally cost-effective or even cost saving across a range of epidemiological scenarios.
Broader vaccination strategies may be cost-effective in certain contexts, depending on disease burden, vaccine costs and programmatic factors.
Most studies originate from high-income countries, limiting their generalizability to other settings.
SAGE recommended that countries should consider routine COVID-19 vaccination for those groups at highest risk of severe COVID-19 disease.
These include oldest adults;{25} older adults{26} with significant comorbidities or severe obesity; residents in care and long-term care facilities; and individuals aged 6 months or over, who are moderately or severely immunocompromised.
For these groups – whether they are unvaccinated or were vaccinated more than 6 months earlier – SAGE recommended at least one dose per year, and preferably two doses administered 6 months apart, owing to the waning of protection against severe COVID-19 disease by 6 months after the last dose.
Cost–effectiveness and programmatic feasibility should be considered when determining the number of doses to be administered per year.
SAGE also recommended that countries may consider routine COVID-19 vaccination of additional groups based on local context, cost–effectiveness and programmatic feasibility.
These additional groups include the following:
• Older adults without significant comorbidities or severe obesity; adults (not included in the older adult category), adolescents and children with significant comorbidities or severe obesity; and health workers and other care providers. These groups, whether unvaccinated or previously vaccinated more than 6 months earlier, may be vaccinated with at least one dose per year.
• People who are pregnant, whether unvaccinated or previously vaccinated more than 6 months earlier. This group may be vaccinated with one COVID-19 vaccine dose during each pregnancy, at any stage, though ideally during the second trimester. The aim is to optimize protection against severe COVID-19 for the pregnant person, prevent adverse pregnancy outcomes and protect the infant during the first months of life.
• Previously unvaccinated healthy children aged 6–23 months. This age group may be vaccinated if a significant burden is documented; revaccination is not routinely recommended.
Some of the research priorities recommended by SAGE were further assessment of the burden, societal impact and vaccine effectiveness against post-COVID-19 condition, using the WHO standardized definition;{27} studies on cost–effectiveness of COVID-19 vaccination, particularly in low- and middle-income countries, and among groups such as health workers and children; and studies on the social and behavioural drivers of COVID-19 vaccine uptake, to address hesitancy and guide interventions to achieve high confidence and uptake.
SAGE recommendations will inform the development of a WHO vaccine position paper on COVID-19 vaccines; the position paper will replace the WHO SAGE interim guidance reflected in the COVID-19 vaccines roadmap.{28}
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{24} World Health Organization (2026). Global Advisory Committee on Vaccine Safety (GACVS): COVID-19 vaccines – Subcommittee. Geneva: WHO; [cited 2026 Mar 10]. Available from: https://www.who.int/groups/global-advisory-committee-on-vaccine-safety/topics/covid-19-vaccines/subcommittee, accessed 30 April 2026).
{25} Age cut-off should be determined by countries – often it is 75 or 80 years.
{26} Age cut-off should be determined by countries – often it is 50 or 60 years
{27} WHO standardized definition for adults: Post-COVID-19 condition occurs in individuals with a history of probable or confirmed SARS-CoV-2 infection, usually 3 months from the onset of COVID-19, with symptoms that last for at least 2 months and cannot be explained by an alternative diagnosis. (https://www.who.int/publications/i/item/WHO-2019-nCoV-Post_COVID-19_condition-Clinical_case_definition-2021.1, accessed 30 April 2026); WHO standardized definition for children and adolescents: Post-COVID-19 condition in children and adolescents occurs in individuals with a history of confirmed SARS-CoV-2 infection, with at least one persistent physical symptom lasting for at least 12 weeks after testing positive, that impacts everyday functioning and cannot be explained by another diagnosis. (https://www.who.int/publications/i/item/WHO-2019-nCoV-Post-COVID-19-condition-CA-Clinical-case-definition-2023-1, accessed 30 April 2026)
{28} WHO SAGE Roadmap for prioritizing uses of COVID-19 vaccines (https://www.who.int/publications/i/item/WHO-2019-nCoV-Vaccines-SAGE-Prioritization-2023.1, accessed 30 April 2026)
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Source:
Link: https://www.who.int/publications/journals/weekly-epidemiological-record
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