Managing Influenza in Primary Care: Insights into the 2024 Flu Season

As primary care health professionals in the UK prepare for the 2024-2025 flu season, it is essential to understand the most common influenza types and their potential impact on patient care. Influenza viruses mutate frequently, making seasonal trends and vaccination updates critical for effective prevention and management. This article provides an overview of the common flu strains circulating in the UK this year, highlighting the importance of vaccination for at-risk groups.

Common Influenza Strains in 2024

During the 2024-2025 flu season, surveillance data suggests that several key influenza strains are circulating, consistent with previous years but with notable trends in dominant strains. The primary types are:

Influenza A(H1N1)pdm09: First detected in the 2009 pandemic, this strain remains active globally. In the UK, influenza A(H1N1) pdm09 has been responsible for a substantial proportion of flu cases. In Scotland, for example, it accounted for 4.2% of the total influenza cases detected in early 2024. The strain continues to circulate with the potential to affect all age groups but is particularly notable in younger populations

Influenza A(H3N2): Another significant subtype of influenza A, H3N2 has been linked to more severe illness, especially in older adults. H3N2 is often associated with increased hospitalizations, especially among individuals aged 65 and over, as well as those with comorbidities. In early 2024, H3N2 represented 4.9% of all flu cases in the UK.

Influenza B: Influenza B viruses tend to cause less severe symptoms compared to influenza A but are still responsible for a considerable number of cases, particularly in children and adolescents. The two major lineages of influenza B (Victoria and Yamagata) are included in the quadrivalent flu vaccines (QIV), ensuring broad coverage. During the current season, influenza B accounted for 1.7% to 2% of flu cases

Influenza A (non-subtyped): A small but noteworthy portion of flu cases (around 2% in the UK) fall into the category of influenza A that cannot be specifically subtyped. While these cases do not dominate the season, they require attention, especially in individuals with preexisting health conditions

The Role of Vaccination in Prevention

The UK's flu vaccination programme remains the cornerstone of public health strategies to reduce the burden of influenza, particularly in high-risk groups. For the 2024-2025 season, the recommended vaccines are quadrivalent influenza vaccines (QIV), which cover two A strains (H1N1 and H3N2) and two B strains. These vaccines are offered to a wide range of at-risk populations, including:

Children: All primary school-aged children, as well as some secondary school children, are eligible for the nasal spray vaccine (LAIV), which is generally more effective in this age group. Children with contraindications to LAIV will receive the inactivated.

Older adults and vulnerable individuals: Those over 65 and individuals with chronic health conditions are offered the adjuvanted quadrivalent influenza vaccine (aQIV), which provides enhanced protection.

Pregnant women: Influenza poses a significant risk during pregnancy, increasing the likelihood of complications such as pneumonia or even preterm birth. Vaccination during any stage of pregnancy is strongly encouraged to protect both mother and child

Implications for Primary Care

Primary care practitioners play a critical role in identifying and vaccinating at-risk groups, ensuring that flu immunizations are administered promptly before the peak of the season. According to government guidance, those who are eligible should receive the flu vaccine ideally before flu begins circulating in late autumn

 In addition to vaccination, education on hygiene practices, early diagnosis, and prompt antiviral treatment are key components of flu management in primary care settings.

Moreover, healthcare providers should remain vigilant for co-infections, as rhinovirus and other respiratory pathogens are also circulating at significant levels. The overlap between flu and other viral infections could complicate patient management, especially in those with comorbid conditions.

Conclusion

For the 2024-2025 flu season, the most common influenza strains in the UK include A(H1N1) pdm09, A(H3N2), and influenza B, all of which are covered by the quadrivalent vaccines in use. Primary care providers must prioritize vaccination for vulnerable populations and remain prepared for the seasonal surge in flu cases. By staying informed of the latest flu trends and employing preventive measures, primary care professionals can help mitigate the impact of flu on their patients and the broader community.

As you prepare for the upcoming flu season, it’s important to stay updated not only on common influenza strains but also on managing broader minor ailments and paediatric illnesses. For healthcare professionals seeking to expand their expertise, PDUK offers valuable courses designed to enhance your practical knowledge in these areas:

1. Paediatric Minor Illness – This course focuses on diagnosing and managing common paediatric conditions, enabling you to confidently handle a range of minor illnesses in children. Ideal for primary care professionals who regularly interact with younger patients.

2. Minor Ailments Essentials – A comprehensive course that equips practitioners with the essential skills to assess and manage everyday minor ailments. This is perfect for those looking to refine their clinical decision-making in handling common conditions seen in primary care.

Both courses provide practical insights and up-to-date best practices, making them excellent additions to your continuing professional development (CPD). Visit the links to explore more details!

References:

GOV.UK (2024) Surveillance of influenza and other seasonal respiratory viruses in the UK, winter 2023 to 2024. Available at: www.gov.uk [Accessed 1 October 2024].

GOV.UK (2024) Flu vaccination programme 2024 to 2025: information for healthcare practitioners. Available at: www.gov.uk [Accessed 1 October 2024].