Before the 1968 emergence of the H3N2 subtype, influenza vaccine development comprised the established approaches available at the time to respond to seasonal and emerging strains. The review summarizes historical vaccine strategies and development pathways that were in place leading up to the 1968 event, noting that influenza vaccine design and deployment aimed to mitigate morbidity and mortality from circulating influenza A viruses. The source emphasizes that understanding these historical strategies provides context for actions taken when the 1968 H3N2 virus emerged.
In 1968, a new influenza A virus subtype, H3N2, emerged and spread globally, an event commonly referred to as the 1968 H3N2 pandemic or the Hong Kong pandemic. The review reports that up to two million fatalities have been linked to the 1968 H3N2 pandemic. Following its emergence, the H3N2 subtype became established and has continued to circulate as seasonal influenza A virus among humans. The authors describe the course of emergence and geographic dissemination during the pandemic, framing the historical epidemiology as a foundation for evaluating vaccine and public health responses.
The review highlights the vaccination strategies that were used during the 1968 H3N2 pandemic period. It details how vaccines were developed, updated and distributed in response to the newly circulating H3N2 strain. The authors present these strategies as a mix of proactive vaccine development and reactive adjustments once the pandemic strain was recognized, stressing the role of vaccine updates in combating antigenically novel influenza viruses like H3N2.
Beyond vaccination, the review outlines precautionary measures and other proactive actions taken in 1968 to reduce pandemic impact. These included public health communication, surveillance efforts and non-vaccine countermeasures intended to slow spread and protect vulnerable populations. The authors stress that these measures, together with vaccine strategies, formed the broader public health response during the 1968 pandemic.
The authors argue that historical experience from the 1968 H3N2 pandemic should inform contemporary pandemic preparedness. They recommend updating past strategies in light of new scientific findings and the operational lessons learned during the COVID-19 pandemic. Specific points made by the source include the continuing threat posed by zoonotic influenza viruses—citing the global spread of H5N1 and discovery of novel IAVs with zoonotic or pandemic potential—and the importance of maintaining vigilance as seasonal influenza viruses undergo antigenic change. The review emphasizes improving countermeasures, surveillance systems and public communication to limit future pandemic ramifications and enhance readiness for the next IAV pandemic.
The review was published in Vaccine in 2026 (Volume 89:128877; doi: 10.1016/j.vaccine.2026.128877; Epub 2026 Jul 2) and is indexed with PMID 42391691. The authors are affiliated with the Ludwig Boltzmann Institute for Science Outreach and Pandemic Preparedness at the Medical University of Vienna and additional institutions for one author. The source includes a declaration of competing interests: one author reports patent filings and royalty payments related to serological assays and vaccine platforms, company affiliations and consultancy relationships with vaccine or biotechnology companies. These competing interests are disclosed in the original article as provided in the source.
The 1968 H3N2 pandemic illustrates how an antigenically novel influenza A subtype can rapidly become pandemic and then establish sustained seasonal circulation. The review connects the historical vaccine development and public health responses of 1968 to current concerns: zoonotic spill-over events (for example H5N1), ongoing antigenic drift in seasonal strains, and the need to integrate lessons from the COVID-19 pandemic into influenza preparedness. The authors conclude that continual improvement of vaccines, countermeasures, surveillance and public communication is essential to reduce morbidity and mortality from future influenza pandemics.
Note: The source abstract and metadata provided the basis for this summary. Detailed descriptions of specific vaccine formulations, trial results, timelines, or exact operational measures taken in 1968 were not reported in the source text excerpt used here.