Auto-antibodies to type I IFNs can underlie adverse reactions to yellow fever live attenuated vaccine.

Yellow fever virus (YFV) live attenuated vaccine can, in rare cases, cause life-threatening disease, typically in patients with no previous history of severe viral illness. Autosomal recessive (AR) complete IFNAR1 deficiency was reported in one 12-yr-old patient. Here, we studied seven other previously healthy patients aged 13 to 80 yr with unexplained life-threatening YFV vaccine-associated disease. One 13-yr-old patient had AR complete IFNAR2 deficiency. Three other patients vaccinated at the ages of 47, 57, and 64 yr had high titers of circulating auto-Abs against at least 14 of the 17 individual type I IFNs. These antibodies were recently shown to underlie at least 10% of cases of life-threatening COVID-19 pneumonia. The auto-Abs were neutralizing in vitro, blocking the protective effect of IFN-α2 against YFV vaccine strains. AR IFNAR1 or IFNAR2 deficiency and neutralizing auto-Abs against type I IFNs thus accounted for more than half the cases of life-threatening YFV vaccine-associated disease studied here. Previously healthy subjects could be tested for both predispositions before anti-YFV vaccination.

Inherited IFNAR1 deficiency in otherwise healthy patients with adverse reaction to measles and yellow fever live vaccines.

Vaccination against measles, mumps, and rubella (MMR) and yellow fever (YF) with live attenuated viruses can rarely cause life-threatening disease. Severe illness by MMR vaccines can be caused by inborn errors of type I and/or III interferon (IFN) immunity (mutations in IFNAR2, STAT1, or STAT2). Adverse reactions to the YF vaccine have remained unexplained. We report two otherwise healthy patients, a 9-yr-old boy in Iran with severe measles vaccine disease at 1 yr and a 14-yr-old girl in Brazil with viscerotropic disease caused by the YF vaccine at 12 yr. The Iranian patient is homozygous and the Brazilian patient compound heterozygous for loss-of-function IFNAR1 variations. Patient-derived fibroblasts are susceptible to viruses, including the YF and measles virus vaccine strains, in the absence or presence of exogenous type I IFN. The patients' fibroblast phenotypes are rescued with WT IFNAR1 Autosomal recessive, complete IFNAR1 deficiency can result in life-threatening complications of vaccination with live attenuated measles and YF viruses in previously healthy individuals.

Duration of post-vaccination immunity to yellow fever in volunteers eight years after a dose-response study.

In 2009, Bio-Manguinhos conducted a dose-response study with the yellow fever vaccine, administering the vaccine in the usual mean dose of 27,476 IU (full dose, reference) and in tapered doses (10,447 IU, 3013 IU, 587 IU, 158 IU, and 31 IU) by the usual subcutaneous route and usual volume (0.5 mL). Tapered doses were obtained by dilution in the manufacturer's laboratory, and the test batches presented industrial quality. Doses down to 587 IU showed similar immunogenicity to the full dose (27,476, reference), while the 158 IU and 31 IU doses displayed lower immunogenicity. Seropositivity was maintained at 10 months, except in the group that received the 31 IU dose. The current study aims to determine whether yellow fever seropositivity was maintained eight years after YF vaccination in non-revaccinated individuals. According to the current study's results, seropositivity was maintained in 85% of 318 participants and was similar across groups. The findings support the use of the yellow fever vaccine in fractional doses during outbreaks, but each fractional dose should have at least 587 IU. This study also supports the minimum dose required by WHO, 1000 IU. CLINICAL TRIALS REGISTRATION: Clinicaltrials.gov NCT 03338231.

Adverse events following yellow fever immunization: Report and analysis of 67 neurological cases in Brazil.

Neurological adverse events following administration of the 17DD substrain of yellow fever vaccine (YEL-AND) in the Brazilian population are described and analyzed. Based on information obtained from the National Immunization Program through passive surveillance or intensified passive surveillance, from 2007 to 2012, descriptive analysis, national and regional rates of YFV associated neurotropic, neurological autoimmune disease, and reporting rate ratios with their respective 95% confidence intervals were calculated for first time vaccinees stratified on age and year. Sixty-seven neurological cases were found, with the highest rate of neurological adverse events in the age group from 5 to 9 years (2.66 per 100,000 vaccine doses in Rio Grande do Sul state, and 0.83 per 100,000 doses in national analysis). Two cases had a combination of neurotropic and autoimmune features. This is the largest sample of YEL-AND already analyzed. Rates are similar to other recent studies, but on this study the age group from 5 to 9 years of age had the highest risk. As neurological adverse events have in general a good prognosis, they should not contraindicate the use of yellow fever vaccine in face of risk of infection by yellow fever virus.

17DD yellow fever vaccine: a double blind, randomized clinical trial of immunogenicity and safety on a dose-response study.

OBJECTIVE: To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation. RESULTS: Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups. METHODS: Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions. CONCLUSION: In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. INTERNATIONAL REGISTER: ISRCTN 38082350.

Follow-up study of unknowingly pregnant women vaccinated against rubella in Brazil, 2001-2002.

BACKGROUND: Brazil conducted mass immunization of women of childbearing age in 2001 and 2002. Surveillance was initiated for vaccination of women during pregnancy to monitor the effects of rubella vaccination on fetal outcomes. METHODS: Women vaccinated while pregnant or prior to conception were reported to the surveillance system. Susceptibility to rubella infection was determined by anti-rubella immunoglobulin (Ig) M and IgG immunoassays. Susceptible women were observed through delivery. Live-born infants were tested for anti-rubella IgM antibody; IgM-seropositive newborns were tested for viral shedding and observed for 12 months for signs of congenital rubella syndrome. Incidence of congenital rubella infection was calculated using data from 7 states. RESULTS: A total of 22 708 cases of rubella vaccination during pregnancy or prior to conception were reported nationwide, 20,536 (90%) of which were from 7 of 27 states in Brazil. Of these, 2332 women were susceptible to rubella infection at vaccination. Sixty-seven (4.1%) of 1647 newborns had rubella IgM antibody (incidence rate, 4.1 congenital infections per 100 susceptible women vaccinated during pregnancy [95% confidence interval, 3.2-5.1]). None of the infants infected with rubella vaccine virus was born with congenital rubella syndrome. CONCLUSIONS: As rubella elimination goals are adopted worldwide, evidence of rubella vaccine safety aids in planning and implementation of mass adult immunization.

Mutual interference on the immune response to yellow fever vaccine and a combined vaccine against measles, mumps and rubella.

A randomized trial was conducted to assess the immunogenicity and reactogenicity of yellow fever vaccines (YFV) given either simultaneously in separate injections, or 30 days or more after a combined measles-mumps-rubella (MMR) vaccine. Volunteers were also randomized to YFV produced from 17DD and WHO-17D-213 substrains. The study group comprised 1769 healthy 12-month-old children brought to health care centers in Brasilia for routine vaccination. The reactogenicity was of the type and frequency expected for the vaccines and no severe adverse event was associated to either vaccine. Seroconversion and seropositivity 30 days or more after vaccination against yellow fever was similar across groups defined by YFV substrain. Subjects injected YFV and MMR simultaneously had lower seroconversion rates--90% for rubella, 70% for yellow fever and 61% for mumps--compared with those vaccinated 30 days apart--97% for rubella, 87% for yellow fever and 71% for mumps. Seroconversion rates for measles were higher than 98% in both comparison groups. Geometric mean titers for rubella and for yellow fever were approximately three times higher among those who got the vaccines 30 days apart. For measles and mumps antibodies GMTs were similar across groups. MMR's interference in immune response of YFV and YFV's interference in immune response of rubella and mumps components of MMR had never been reported before but are consistent with previous observations from other live vaccines. These results may affect the recommendations regarding primary vaccination with yellow fever vaccine and MMR.

Incidência de episódios hipotônicos-hiporresponsivos associados à vacina combinada DTP/Hib usada no Programa Nacional de Imunizações / Incidence of hypotonic-hyporesponsive episodes associated to the combined DTP/Hib vaccine used in Brazilian National Immunizations Program

OBJETIVO: Avaliar a segurança da vacina combinada de difteria-tétano-coqueluche de células inteiras e Haemophilus influenzae tipo b usada no Programa Nacional de Imunizações, e em especial a incidência de episódios hipotônicos-hiporresponsivos. MÉTODO: Acompanhamento de uma coorte de 21.064 lactentes (20.925 ou 99,7 por cento aderiram ao protocolo de estudo), nas 48 horas após a aplicação da vacina de difteria, tétano, coqueluche de células inteiras e Haemophilus influenzae tipo b em centros de saúde na cidade do Rio de Janeiro, para determinar e investigar eventos adversos graves, espontâneos e solicitados. Cada criança foi monitorada durante somente uma dose. RESULTADOS: A incidência de episódios hipotônicos-hiporresponsivos foi de 1:1.744 doses (casos confirmados) e de 1:1.495 doses (casos confirmados mais casos suspeitos). A taxa de incidência de convulsões foi de 1:5.231 doses. Não foram detectados casos de apnéia. Esses resultados são comparáveis àqueles relatados na literatura para a vacina contra difteria-tétano-coqueluche de células inteiras. CONCLUSÃO: A vacina contra difteria, tétano, coqueluche de células inteiras e Haemophilus influenzae tipo b em estudo pode ser usada com segurança no Programa Nacional de Imunizações, de acordo com as precauções e contra-indicações correntes.

OBJECTIVE:To evaluate the safety of a combined diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine used on the Brazilian National Immunizations Program, chiefly the incidence of hypotonic-hyporesponsive episodes. METHOD: Follow-up of a cohort of 21,064 infants (20,925 or 99.7 percent adhered to the study protocol), within 48 hours of vaccination with diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine in health care units in the City of Rio de Janeiro, to ascertain and investigate spontaneous and solicited severe adverse events. Each child was followed-up for one dose only. RESULTS: The rate of hypotonic-hyporesponsive episodes was 1/1,744 doses (confirmed cases) and 1/1,495 doses (confirmed plus suspect cases). The rate of convulsions was 1/5,231 doses. No cases of apnea were detected. These results are comparable to those found in the literature with diphtheria-tetanus-whole cell pertussis vaccine. CONCLUSION: The diphtheria-tetanus-whole cell pertussis-Haemophilus influenzae type b vaccine under study can be safely used in the National Immunizations Program, according to the current precautions and contraindications.