LAIV availability

Please see below explanation why UKHSA cannot specify the date of availability for LAIV at this time:

The availability of LAIV cannot be confirmed until late summer. This is due to the complex manufacturing and regulatory processes (some of which are unique to LAIV) that are required before the vaccine is released to the market, further to a rapid production period following the WHO announcement on strains in late February each year.

As with all vaccines, flu vaccines are biological products and manufacture can be unpredictable. But unlike other vaccines used in the routine immunisation programme, flu vaccines are ‘just in time’ products, manufactured under very pressurised timelines – and in very large volumes, both of which add risk and complexity to the process.

Additionally, there are multiple flu vaccine ‘platforms’ (e.g: egg-based and cell-based), and vaccine production systems differ across these platforms which can affect timelines for individual products. LAIV is an egg-based vaccine.

Deliveries of LAIV to UKHSA are phased throughout the autumn, and UKHSA opens ordering as soon as sufficient vaccine has been made available to support the demand from providers of the programme, and in 2025 it is anticipated that this will be in early September.

UKHSA advise that the likelihood of vaccine availability should be taken into account when vaccination sessions are being arranged, to reduce the risk of disruption to planned activity should vaccine not yet be available, and providers of the programmed should check the ImmForm news page regularly for the most up to date information.

Additional notes:

Flu viruses can change from one winter to the next, so flu vaccines are updated ahead of each winter to give protection against the strains of flu that are most likely to be circulating. The World Health Organization (WHO) monitors the epidemiology of influenza viruses throughout the world, and each year based on this data makes recommendations about the virus strains to be included in vaccines for the forthcoming winter for the northern and southern hemispheres (https://www.who.int/teams/global-influenza-programme/vaccines/who-recommendations ). As the WHO needs to have reviewed the most up to date global surveillance data (in order to make the most informed recommendation about which viruses should be used in the upcoming seasons vaccines), the Northern hemisphere announcement cannot be made until the end of February. This is so as much surveillance data as possible from the previous winter can be considered.  Influenza vaccines are therefore prepared in line with the WHO recommendation, with manufacturers and regulators work at pace between the WHO announcement (at the end of February) and the autumn, to ensure that vaccines are available for the upcoming season.

If you have any queries regarding the information above please contact the London Region Flu/Covid team directly at: England.london-covid19voc@nhs.net