New Developments in Seasonal Vaccines

What is it?
Quadrivalent vaccines (QIV) provide coverage against two influenza A virus strains and two influenza B virus strains; the traditional trivalent vaccines (TIV) provide coverage against two influenza virus strains and only one influenza B virus strain.

The rationale
Two influenza B lineages (Yamagata and Victoria) have been co-circulating since the 1980s (Chen 2008), although the prevalence of the two strains varies each year. Vaccination against one lineage of influenza B virus offers poor cross protection against infection by the other lineage. Thus vaccine effectiveness is markedly reduced when there is a mismatch between the vaccine coverage and the circulating lineage of influenza B. This discordance is important, because, as noted above, trivalent vaccines provide coverage against only one of the two influenza B lineages.

Influenza B Virus Disease Burden
On average, influenza B accounts for about one quarter of total influenza activity each season, but its activity can vary and can range from 1% to 60% of the total seasonal influenza activity. (Ambrose 2012). In addition, it causes epidemics every 2 to 4 years. (Belshe 2010).

Although influenza B infects patients of all ages, it causes a disproportionately higher amount of disease relative to influenza A in children and young adults. Overall, influenza B was responsible for 34% of reported pediatric influenza deaths (Ambrose 2012).

Influenza B infection is also prominent in older adults causing nursing home outbreaks. (Camilloni 2010)

Safety
Quadrivalent influenza vaccines are made in the same way as the trivalent influenza vaccines. Studies have shown (Beran 2013, Block 2013, Greenberg 2013 inter alia) that QIV vaccines have a safety profile similar to TIV vaccines, with similar—mostly mild—side effects.

Cost and benefit
The QIV is more costly than the TIV and the formulation of a quadrivalent vaccine represents an increased cost to the manufacturers, and to the healthcare system. Modeling studies have suggested that the use of a quadrivalent vaccine would have had a beneficial public health impact in the years 1999 to 2009 (Reed 2012 ) and may also have been associated with substantial savings of healthcare costs, including those incurred by third-party payers (Lee 2012, 2013).

 

Recent Vaccine Literature

Ando S.  Estimation of the Effectiveness of Quadrivalent Influenza Vaccines by Distinguishing Between Influenza A (H1N1) pdm09 and Influenza A (H3N2) Using Rapid Influenza Diagnostic Tests During the 2018-2019 Season.  Intern Med. 2019 Nov 29. Full Text

Chen LJ, et al. Molecular Epidemiology and Vaccine Compatibility Analysis of Seasonal Influenza Viruses in Wuhan, 2016-2019.
Virol Sin. 2020 May 11. Full Text 

Dhamayanti M, et al.  Immunogenicity and safety of Quadrivalent Influenza HA vaccine in Indonesian children: An open-labeled, bridging, clinical study.  Vaccine. 2019 Dec 17. Full Text

Jiang M, et al.  Cost-effectiveness of quadrivalent versus trivalent influenza vaccine for elderly population in China. Vaccine. 2019 Nov 28. Full Text

Kelly HG, et al. Self-assembling influenza nanoparticle vaccines drive extended germinal center activity and memory B cell maturation.
JCI Insight. 2020 May 21;5(10):136653. Full Text 

Rockman S, Laurie K, Barr I. Pandemic Influenza Vaccines: What did We Learn from the 2009 Pandemic and are We Better Prepared Now?
Vaccines (Basel). 2020 May 7;8(2):E211. Full Text