Format

Send to

Choose Destination
Vaccine. 2017 May 2;35(19):2558-2568. doi: 10.1016/j.vaccine.2017.03.063. Epub 2017 Apr 3.

Influenza vaccination responses: Evaluating impact of repeat vaccination among health care workers.

Author information

1
WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, 792 Elizabeth St, Melbourne, VIC 3000, Australia; Department of Infectious Diseases/Infection Prevention, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia.
2
WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, 792 Elizabeth St, Melbourne, VIC 3000, Australia.
3
Department of Infectious Diseases/Infection Prevention, Peter MacCallum Cancer Centre, 305 Grattan Street, Melbourne, VIC 3000, Australia.
4
WHO Collaborating Centre for Reference and Research on Influenza, Peter Doherty Institute for Infection and Immunity, 792 Elizabeth St, Melbourne, VIC 3000, Australia; Fielding School of Public Health, University of California, Los Angeles, USA; School of Population and Global Health, University of Melbourne, Melbourne, Australia. Electronic address: sheena.sullivan@influenzacentre.org.

Abstract

OBJECTIVE:

To compare the antibody response to influenza between health care workers (HCWs) who have received multiple vaccinations (high vaccination group) and those who have received fewer vaccinations (low vaccination group).

DESIGN:

Prospective serosurvey.

SETTING:

Tertiary referral hospital.

PARTICIPANTS:

Healthcare workers.

METHODS:

Healthcare workers were vaccinated with the 2015 southern hemisphere trivalent influenza vaccine. Influenza antibody titres were measured pre-vaccination, 21-28days post-vaccination and 6months post-vaccination. Antibody titres were measured using the haemagglutination inhibition assay. Levels of seropositivity and estimated geometric mean titres were calculated.

RESULTS:

Of the 202 HCWs enrolled, 182 completed the study (143 high vaccination and 39 low vaccination). Both vaccination groups demonstrated increases in post-vaccination geometric mean titres, with greater gains in the low vaccination group. Seropositivity remained high in both high and low vaccination groups post-vaccination. The highest fold rise was observed among HCWs in the low vaccination group against the H3N2 component of the vaccine.

CONCLUSIONS:

Both high and low vaccination groups in our study demonstrated protective antibody titres post-vaccination. The findings from the current study are suggestive of decreased serological response among highly vaccinated HCWs. More studies with larger sample sizes and a greater number of people in the vaccine-naïve and once-vaccinated groups are required to confirm or refute these findings before making any policy changes.

KEYWORDS:

Antibody; Focus reduction assay; Healthcare worker; Hemagglutination inhibition assay; Immunogenicity; Influenza vaccine

PMID:
28385605
DOI:
10.1016/j.vaccine.2017.03.063
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center