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Journal of Travel Medicine Mar 2020Pregnant travellers and their offspring are vulnerable to severe outcomes following a wide range of infections. Vaccine-preventable diseases can have a particularly... (Meta-Analysis)
Meta-Analysis
Pregnant travellers and their offspring are vulnerable to severe outcomes following a wide range of infections. Vaccine-preventable diseases can have a particularly severe course in pregnant women, but little is known about the safety of travel vaccines in pregnant women. We performed a systematic review of all published literature concerning the safety of vaccines frequently given to travellers such as yellow fever, MMR (mumps, measles and rubella), influenza, Tdap (tetanus, diphtheria and pertussis), meningococcus, hepatitis A and B, rabies, polio, typhoid fever, tick-borne encephalitis and Japanese encephalitis vaccines. We included case series, cohort studies and randomized controlled trials (RCTs). For the meta-analysis, we included only RCTs that compared the administration of a vaccine to placebo or to no vaccine. Outcome measures included severe systemic adverse events, maternal outcomes related to the course of pregnancy, neonatal outcomes and local adverse events. We calculated the risk ratio and its 95% confidence interval as the summary measure. The safety of influenza vaccine is supported by high-quality evidence. For Tdap vaccine, no evidence of any harm was found in the meta-analysis of RCTs. A slight increase in chorioamnionitis rate was reported in 3 out of 12 observational studies. However, this small possible risk is far outweighed by a much larger benefit in terms of infant morbidity and mortality. Meningococcal vaccines are probably safe during pregnancy, as supported by RCTs comparing meningococcal vaccines to other vaccines. Data from observational studies support the safety of hepatitis A, hepatitis B and rabies vaccines, as well as that of the live attenuated yellow fever vaccine. We found little or no data about the safety of polio, typhoid, Japanese encephalitis, tick-borne encephalitis and MMR vaccines during pregnancy.
Topics: Female; Humans; Pregnancy; Travel Medicine; Travel-Related Illness; Vaccination; Vaccines
PubMed: 31616947
DOI: 10.1093/jtm/taz074 -
Clinical Infectious Diseases : An... Jun 2020Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the...
BACKGROUND
Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the risk diphtheria poses when civil unrest interrupts vaccination and healthcare access. Lack of interest over the last century resulted in knowledge gaps about diphtheria's epidemiology, transmission, and control.
METHODS
We conducted 9 distinct systematic reviews on PubMed and Scopus (March-May 2018). We pooled and analyzed extracted data to fill in these key knowledge gaps.
RESULTS
We identified 6934 articles, reviewed 781 full texts, and included 266. From this, we estimate that the median incubation period is 1.4 days. On average, untreated cases are colonized for 18.5 days (95% credible interval [CrI], 17.7-19.4 days), and 95% clear Corynebacterium diphtheriae within 48 days (95% CrI, 46-51 days). Asymptomatic carriers cause 76% (95% confidence interval, 59%-87%) fewer cases over the course of infection than symptomatic cases. The basic reproductive number is 1.7-4.3. Receipt of 3 doses of diphtheria toxoid vaccine is 87% (95% CrI, 68%-97%) effective against symptomatic disease and reduces transmission by 60% (95% CrI, 51%-68%). Vaccinated individuals can become colonized and transmit; consequently, vaccination alone can only interrupt transmission in 28% of outbreak settings, making isolation and antibiotics essential. While antibiotics reduce the duration of infection, they must be paired with diphtheria antitoxin to limit morbidity.
CONCLUSIONS
Appropriate tools to confront diphtheria exist; however, accurate understanding of the unique characteristics is crucial and lifesaving treatments must be made widely available. This comprehensive update provides clinical and public health guidance for diphtheria-specific preparedness and response.
Topics: Child; Diphtheria; Disease Outbreaks; Humans; Vaccination
PubMed: 31425581
DOI: 10.1093/cid/ciz808 -
International Journal of Environmental... Jul 2019A literature review was conducted to identify evidence of cases and outbreaks of vaccine-preventable diseases (VPDs) that have been reported from on board ships and the...
A literature review was conducted to identify evidence of cases and outbreaks of vaccine-preventable diseases (VPDs) that have been reported from on board ships and the methods applied on board for prevention and control, worldwide, in 1990 to April 2019. Moreover, evidence from seroprevalence studies for the same diseases were also included. The literature review was conducted according to Preferred Reporting Items for Systematic reviews (PRISMA) guidelines. A total of 1795 cases (115 outbreaks, 7 case reports) were identified, the majority were among crew (1466/1795, 81.7%) and were varicella cases (1497, 83.4%). The origin of crew cases was from sub-tropical countries in many reports. Measles (40 cases, 69% among crew), rubella (47, 88.7%), herpes zoster (9, 69.2%) and varicella cases (1316, 87.9%) were more frequent among crew. Mumps cases were equal among passengers and crew (22/22). Hepatitis A (73/92, 70.3%), meningococcal meningitis (16/29, 44.8%), and pertussis (9/9) were more frequent among passengers. Two outbreaks resulted in 262 secondary measles cases on land. Review results were used to draft a new chapter for prevention and control of VPDs in the European Manual for Hygiene Standards and Communicable Disease Surveillance on Passenger Ships. Despite past and current evidence for cross-border VPD transmission and maritime occupational risks, documented pre-employment examination of immune status, vaccination of seafarers, and travel advice to passengers are not yet regulated.
Topics: Emigration and Immigration; Employment; Humans; Immunization; Ships; Travel; Vaccine-Preventable Diseases
PubMed: 31366029
DOI: 10.3390/ijerph16152713 -
Expert Review of Vaccines Sep 2019: In Asia Pacific, most countries recommend a monovalent hepatitis B virus (HBV) vaccine dose at birth followed by primary vaccination series including three or four...
Integration of hexavalent diphtheria, tetanus, acellular pertussis, hepatitis B virus, inactivated poliomyelitis and Haemophilus influenzae type b conjugate vaccine within existing national recommendations following a birth dose of monovalent hepatitis B virus vaccine: results of a systematic...
: In Asia Pacific, most countries recommend a monovalent hepatitis B virus (HBV) vaccine dose at birth followed by primary vaccination series including three or four doses of combination vaccines against diphtheria, tetanus, and pertussis, with or without type b (Hib), HBV or poliomyelitis antigens. If hexavalent conjugate vaccines against diphtheria-tetanus-acellular pertussis-HBV-inactivated poliovirus-Hib (DTPa-HBV-IPV/Hib) replace the vaccines included in the primary vaccination series, co-administration of lower-valent vaccines would be avoided but infants would receive ≥4 doses of HBV-containing vaccines before the age of 2 years. : We searched for clinical trials conducted in the South-East Asia and Western Pacific Regions (World Health Organization geographic definition), investigating vaccination regimens with >3 doses of HBV-containing vaccines in infants, including a monovalent HBV vaccine birth dose and ≥1 dose of GSK's hexavalent DTPa-HBV-IPV/Hib vaccine. : The six clinical trials included in this review showed that infants who received the monovalent HBV vaccine at birth and three or four doses of DTPa-HBV-IPV/Hib vaccine achieved protective immunogenic titers with a clinically acceptable safety profile. Our results support the integration of hexavalent DTPa-HBV-IPV/Hib vaccine within existing national recommendations in the Asia Pacific region to reduce the number of injections during infancy.
Topics: Databases, Factual; Diphtheria; Diphtheria-Tetanus-acellular Pertussis Vaccines; Haemophilus Infections; Haemophilus influenzae type b; Hepatitis B; Hepatitis B Vaccines; Hepatitis B virus; Humans; Immunization Schedule; Poliomyelitis; Tetanus; Vaccines, Combined; Vaccines, Conjugate; Whooping Cough
PubMed: 31328999
DOI: 10.1080/14760584.2019.1646643