High coverage and safety of influenza A (H1N1) 2009 monovalent vaccination among health care personnel in Thailand

Estimating the number of averted illnesses and deaths as a result of vaccination against an influenza pandemic in nine low- and middle-income countries

BACKGROUND

During the 2009 influenza A(H1N1)pdm09 pandemic, 77 countries received donated monovalent A(H1N1)pdm09 vaccine through the WHO Pandemic Influenza A(H1N1) Vaccine Deployment Initiative. However, 47% did not receive their first shipment until after the first wave of virus circulation, and 8% did not receive their first shipment until after the WHO declared the end of the pandemic. Arguably, these shipments were too late into the pandemic to have a substantial effect on virus transmission or disease burden during the first waves of the pandemic.

OBJECTIVES

In order to evaluate the potential benefits of earlier vaccine availability, we estimated the number of illnesses and deaths that could be averted during a 2009-like influenza pandemic under five different vaccine-availability timing scenarios.

METHODS

We adapted a model originally developed to estimate annual influenza morbidity and mortality burden averted through US seasonal vaccination and ran it for five vaccine availability timing scenarios in nine low- and middle-income countries that received donated vaccine.

RESULTS

Among nine study countries, we estimated that the number of averted cases was 61-216,197 for actual vaccine receipt, increasing to 2,914-283,916 had vaccine been available simultaneously with the United States.

CONCLUSIONS

Earlier delivery of vaccines can reduce influenza case counts during a simulated 2009-like pandemic in some low- and middle-income countries. For others, increasing the number of cases and deaths prevented through vaccination may be dependent on factors other than timely initiation of vaccine administration, such as distribution and administration capacity.

Spinning the globe from west to east: A mixed-method study to examine the impact of pharmacists on immunization advocacy and delivery in Asia Pacific

BACKGROUND

Global effort is key to prevent and control infections effectively. Whereas pharmacists' involvement in the immunization neighborhood, collaborative effort to meet immunization needs of the public, has reduced burden of vaccine-preventable diseases in Western countries, the impact of pharmacist-involved vaccination advocacy and delivery in Asia Pacific remains unclear.

OBJECTIVE

To examine the evidence for impact of pharmacists on immunization advocacy and delivery in Asia Pacific and to assess Singaporean pharmacists' experience in becoming immunizing pharmacists through the American Pharmacists Association's Pharmacy-based Immunization certificate training program.

METHODS

A mixed-method study consisted of systematic review and survey was conducted. The systematic review was conducted by searching PubMed and Cumulative Index to Nursing and Allied Health databases from inception to March 2021. Randomized controlled trials and observational studies related to pharmacist-involved immunization advocacy and training conducted in Asia Pacific were included. Eligible studies were appraised for quality using CONsolidated Standards of Reporting Trials (CONSORT) and STrengthening the Reporting of OBservational checklists. In addition, a 20-item Likert-scale survey evaluated the pharmacists' experience in becoming immunizing pharmacists in Singapore. Frequencies of each response to the survey items were analyzed.

RESULTS

Six studies were eligible for inclusion; 2 assessing impact of pharmacist as immunizer, 3 reporting outcomes of pharmacist-involved vaccine advocacy, and 1 evaluating the structure of pharmacist immunization training. Although study quality was minimal, all studies echoed positive findings as a result of pharmacist-provided immunization advocacy and delivery. Of the 23 pharmacists completing the survey, 91.3% strongly agreed that quality training was important to become immunizing pharmacists.

CONCLUSION

Although limited in number, studies conducted in Asia Pacific reported increased vaccination rates when involving pharmacists. Coupled with the enthusiasm to be trained in immunization advocacy and delivery as elucidated by the Singaporean pharmacists, pharmacists in Asia Pacific should also be advocated for their role in the immunization neighborhood as part of the global effort against vaccine-preventable infectious diseases.

The immunogenicity of the intradermal injection of seasonal trivalent influenza vaccine containing influenza A(H1N1)pdm09 in COPD patients soon after a pandemic

The antibody responses of a reduced-dose intradermal seasonal influenza vaccination have never been studied in COPD patients soon after a pandemic. A total of 149 COPD patients (60 y of age or older) were randomized to receive trivalent influenza vaccine (Sanofi-Pasteur, France) either 9 µg of hemagglutinin (HA) per strain split into 2-site intradermal (ID) injections via the Mantoux technique or one intramuscular (IM) injection of 15 µg of HA per strain. The geometric mean titers, seroconversion factors, seroconversion rates and seroprotection rates for influenza A(H3N2) and B administered through the ID injection (n = 75) were similar to those obtained with the IM injection (n = 74) 4 weeks post-vaccination. The antibody responses for influenza A(H1N1)pdm09 administered through the ID injection were lower than those obtained with the IM injection, but all of these responses met the 3 criteria proposed by the Committee for Proprietary Medicinal Products (CPMP) for annual re-licensure. The seroprotection rates 4 weeks post-vaccination for influenza A(H1N1)pdm09 were 64.0% (95%CI 52.7-74.0%) in the ID group vs. 78.4% (95% CI 67.6-86.3%) in the IM group (p = 0.053). Influenza-related acute respiratory illness (ARI), diagnosed as a 4-fold rise in HI titers with a convalescent titer > 1:40, and/or the RT-PCR between the ID group (5.3%) and the IM group (8.1%) were not significantly different. The reduced-dose intradermal influenza vaccine may expand vaccine coverage in cases of vaccine shortage.

Comparative acceptance of pertussis and influenza immunization among health-care personnel

BACKGROUND

Pertussis and influenza immunization in health-care professionals (HCP) has been shown to lead to significant reduction of nosocomial infections. Parallel campaigns of pertussis and seasonal influenza immunization gave us a unique opportunity to compare attitudes towards influenza and pertussis immunization among HCP and to determine acceptance rates for both or either one of the two immunizations or refusal of both.

METHODS

A questionnaire was sent to HCP to anonymously obtain demographic data, profession, numbers of previous influenza immunizations, acceptance of influenza immunization in the current 2012/13 season, pertussis immunization currently or within the last 10 years, and reasons for acceptance or decline of pertussis and influenza vaccination.

RESULTS

Of 638 HCP with patient contact, 314 (49%) responded and 303 (47%) were included in the analysis. Immunization acceptance rates were 33% for influenza, 57% for pertussis; 24% accepted both immunizations and 34% none of both. Acceptance of influenza immunization was significantly higher in those with one or more previous influenza vaccinations (p<0.005). Among 130 HCP who declined pertussis immunization, missed opportunity (28%) was the dominant reason. Of 204 HCP who declined influenza immunization, the most frequently stated reason was "lack of influenza immunization is not considered an issue" (36%).

CONCLUSIONS

Misconceptions about the efficacy and necessity of pertussis and especially influenza immunization continue to prevail among HCP. Active promotion, personal encouragement, providing more immunization opportunities and other incentives are measures that should be considered to increase the rate of immunization among HCP.

National survey of Thai infection preventions in the era of patient safety

A national survey of infection preventionists was conducted in Thailand to assess career satisfaction, perceived barriers to implementing infection control practices and current sources of continuing education. Despite positive career satisfaction, several barriers were identified, including a lack of physicians to champion infection control efforts and difficulty remaining current with new evidence-based recommendations.

H1N1 and seasonal influenza vaccination of U.S. healthcare personnel, 2010

BACKGROUND

Seasonal influenza vaccination routinely has been recommended for healthcare personnel (HCP) since 1984. The influenza A (H1N1) 2009 monovalent vaccine (H1N1 vaccine) became available in the U.S. in October 2009.

PURPOSE

To assess 2009 H1N1 and seasonal influenza vaccination coverage and identify factors independently associated with vaccination among HCP in the U.S.

METHODS

Data from the 2009-2010 Behavioral Risk Factor Surveillance System (BRFSS) influenza supplemental survey were analyzed in 2011. Multivariable logistic regression and predictive marginal models were performed to identify factors independently associated with vaccination among HCP. The Kaplan-Meier survival analysis procedure was used to estimate the cumulative proportion of people vaccinated.

RESULTS

Among 16,975 HCP surveyed, 2009 H1N1, seasonal, and any-dose vaccination coverage were 34.1% (95% CI=32.7%, 35.5%); 52.4% (95% CI=50.9%, 53.9%); and 58.0% (95% CI=56.5%, 59.5%), respectively, all of which were significantly higher than those for non-HCP (19.1%, 34.9%, and 40.3%, respectively). The H1N1 vaccination coverage among HCP ranged from 18.4% in Mississippi to 56.1% in Massachusetts and seasonal influenza vaccination coverage ranged from 40.4% in Florida to 73.1% in Nebraska. Characteristics independently associated with an increased likelihood of 2009 H1N1, seasonal, and any-dose vaccinations among HCP were as follows: non-Hispanic white, higher income, having a high-risk condition, having health insurance, the ability to see a doctor if needed, and having had a routine checkup in the previous year.

CONCLUSIONS

Vaccination coverage was higher among HCP than non-HCP but still below the national health objective of 90%. Knowledge of national and state-specific H1N1 and seasonal vaccination coverage among HCP is useful for evaluating the vaccination campaign and implementing strategies for increasing yearly seasonal vaccination coverage and improving vaccination coverage among HCP in possible future pandemics.

Short and long-term safety of the 2009 AS03-adjuvanted pandemic vaccine

Background

This study assessed the short and the long term safety of the 2009 AS03 adjuvanted monovalent pandemic vaccine through an active web-based electronic surveillance. We compared its safety profile to that of the seasonal trivalent inactivated influenza vaccine (TIV) for 2010–2011.

Methodology/Principal Findings

Health care workers (HCW) vaccinated in 2009 with the pandemic vaccine (Arepanrix ® from GSK) or HCW vaccinated in 2010 with the 2010–2011 TIV were invited to participate in a web-based active surveillance of vaccine safety. They completed two surveys the day-8 survey covered the first 7 days post-vaccination and the day-29 survey covered events occurring 8 to 28 days after vaccination. Those who reported a problem were called by a nurse to obtain details. The main outcome was the occurrence of a new health problem or the worsening of an existing health condition that resulted in a medical consultation or work absenteeism. For the pandemic vaccine, a six-month follow-up for the occurrence of serious adverse events (SAE) was conducted. Among the 6242 HCW who received the pandemic vaccine, 440 (7%) reported 468 events compared to 328 of the 7645 HCW (4.3%) who reported 339 events after the seasonal vaccine. The 2009 pandemic vaccine was associated with significantly more local reactions than the 2010–2011 seasonal vaccine (1% vs. 0.03%, p<0.001). Paresthesia was reported by 7 HCW (0.1%) after the pandemic vaccine but by none after the seasonal vaccine. For the pandemic vaccine, no clustering of SAE was found in the 6 month follow-up.

Conclusion

The 2009 pandemic vaccine seems to have a good safety profile, similar to the 2010–2011 TIV, with the exception of local reactions. This surveillance was adequately powered to identify AE associated with an excess risk ≥1 per 1000 vaccinations but is insufficient to detect rare AE.

Trial Registration

ClinicalTrials.gov NCT01289418, NCT01318876

Self-reported adverse reactions in 4337 healthcare workers immunizations against novel H1N1 influenza

PURPOSE

The use of the 2009 H1N1 vaccine has generated much debate concerning safety issues among the general population and physicians. It was questioned if this is a safe vaccine. Therefore, we investigated the safety of an inactivated monovalent H1N1 pandemic influenza vaccine

METHODS

We focused on the H1N1 pandemic influenza vaccine Pandemrix® and applied a self reporting questionnaire in a population of healthcare workers (HCWs) and medical students at a major university hospital.

RESULTS

In total, 4337 individuals were vaccinated, consisting of 3808 HCWs and 529 medical students. The vaccination rate of the employees was higher than 40%. The majority of individuals were vaccinated in November 2009. In total, 291 of the 4337 vaccinations were reported to lead to one or more adverse reactions (6.7%). Local reactions were reported in 3.8%, myalgia and arthralgia in 3.7%, fatigue in 3.7%, headache in 3.1%.

CONCLUSIONS

Our data together with available data from several national and international institutions points to a safe pandemic influenza vaccine.