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Duration of post-vaccination immunity against yellow fever in adults.
Vaccine. 2014 Sep 03; 32(39):4977-84.V

Abstract

INTRODUCTION

Available scientific evidence to recommend or to advise against booster doses of yellow fever vaccine (YFV) is inconclusive. A study to estimate the seropositivity rate and geometric mean titres (GMT) of adults with varied times of vaccination was aimed to provide elements to revise the need and the timing of revaccination.

METHODS

Adults from the cities of Rio de Janeiro and Alfenas located in non-endemic areas in the Southeast of Brazil, who had one dose of YFV, were tested for YF neutralising antibodies and dengue IgG. Time (in years) since vaccination was based on immunisation cards and other reliable records.

RESULTS

From 2011 to 2012 we recruited 691 subjects (73% males), aged 18-83 years. Time since vaccination ranged from 30 days to 18 years. Seropositivity rates (95%C.I.) and GMT (International Units/mL; 95%C.I.) decreased with time since vaccination: 93% (88-96%), 8.8 (7.0-10.9) IU/mL for newly vaccinated; 94% (88-97), 3.0 (2.5-3.6) IU/mL after 1-4 years; 83% (74-90), 2.2 (1.7-2.8) IU/mL after 5-9 years; 76% (68-83), 1.7 (1.4-2.0) IU/mL after 10-11 years; and 85% (80-90), 2.1 (1.7-2.5) IU/mL after 12 years or more. YF seropositivity rates were not affected by previous dengue infection.

CONCLUSIONS

Eventhough serological correlates of protection for yellow fever are unknown, seronegativity in vaccinated subjects may indicate primary immunisation failure, or waning of immunity to levels below the protection threshold. Immunogenicity of YFV under routine conditions of immunisation services is likely to be lower than in controlled studies. Moreover, infants and toddlers, who comprise the main target group in YF endemic regions, and populations with high HIV infection rates, respond to YFV with lower antibody levels. In those settings one booster dose, preferably sooner than currently recommended, seems to be necessary to ensure longer protection for all vaccinees.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25090646

Citation

Collaborative group for studies on yellow fever vaccines. "Duration of Post-vaccination Immunity Against Yellow Fever in Adults." Vaccine, vol. 32, no. 39, 2014, pp. 4977-84.
Collaborative group for studies on yellow fever vaccines. Duration of post-vaccination immunity against yellow fever in adults. Vaccine. 2014;32(39):4977-84.
Collaborative group for studies on yellow fever vaccines. (2014). Duration of post-vaccination immunity against yellow fever in adults. Vaccine, 32(39), 4977-84. https://doi.org/10.1016/j.vaccine.2014.07.021
Collaborative group for studies on yellow fever vaccines. Duration of Post-vaccination Immunity Against Yellow Fever in Adults. Vaccine. 2014 Sep 3;32(39):4977-84. PubMed PMID: 25090646.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Duration of post-vaccination immunity against yellow fever in adults. A1 - ,, Y1 - 2014/07/29/ PY - 2014/03/21/received PY - 2014/05/24/revised PY - 2014/07/08/accepted PY - 2014/8/5/entrez PY - 2014/8/5/pubmed PY - 2015/3/31/medline KW - Immunogenicity KW - Vaccination policy KW - Yellow fever vaccine SP - 4977 EP - 84 JF - Vaccine JO - Vaccine VL - 32 IS - 39 N2 - INTRODUCTION: Available scientific evidence to recommend or to advise against booster doses of yellow fever vaccine (YFV) is inconclusive. A study to estimate the seropositivity rate and geometric mean titres (GMT) of adults with varied times of vaccination was aimed to provide elements to revise the need and the timing of revaccination. METHODS: Adults from the cities of Rio de Janeiro and Alfenas located in non-endemic areas in the Southeast of Brazil, who had one dose of YFV, were tested for YF neutralising antibodies and dengue IgG. Time (in years) since vaccination was based on immunisation cards and other reliable records. RESULTS: From 2011 to 2012 we recruited 691 subjects (73% males), aged 18-83 years. Time since vaccination ranged from 30 days to 18 years. Seropositivity rates (95%C.I.) and GMT (International Units/mL; 95%C.I.) decreased with time since vaccination: 93% (88-96%), 8.8 (7.0-10.9) IU/mL for newly vaccinated; 94% (88-97), 3.0 (2.5-3.6) IU/mL after 1-4 years; 83% (74-90), 2.2 (1.7-2.8) IU/mL after 5-9 years; 76% (68-83), 1.7 (1.4-2.0) IU/mL after 10-11 years; and 85% (80-90), 2.1 (1.7-2.5) IU/mL after 12 years or more. YF seropositivity rates were not affected by previous dengue infection. CONCLUSIONS: Eventhough serological correlates of protection for yellow fever are unknown, seronegativity in vaccinated subjects may indicate primary immunisation failure, or waning of immunity to levels below the protection threshold. Immunogenicity of YFV under routine conditions of immunisation services is likely to be lower than in controlled studies. Moreover, infants and toddlers, who comprise the main target group in YF endemic regions, and populations with high HIV infection rates, respond to YFV with lower antibody levels. In those settings one booster dose, preferably sooner than currently recommended, seems to be necessary to ensure longer protection for all vaccinees. SN - 1873-2518 UR - https://www.unboundmedicine.com/medline/citation/25090646/Duration_of_post_vaccination_immunity_against_yellow_fever_in_adults_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0264-410X(14)00947-5 DB - PRIME DP - Unbound Medicine ER -