When should a longer needle be used for intramuscular injection in obese patients? A combined analysis of New Zealand data.

AIM: To estimate thresholds for Body Mass Index (BMI) and arm circumference above which a longer needle is needed to ensure intramuscular (IM) delivery of a vaccine in the deltoid muscle at the site recommended by New Zealand (NZ) immunization guidelines. METHODS: A combined analysis of two studies, including 442 adults, with measurements of arm circumference, BMI and skin to deltoid muscle distance (SDMD) at the NZ immunization guideline-recommended IM injection site. Receiver Operator Characteristic curves identified arm circumference and BMI cut-points that gave 100% sensitivity for SDMD thresholds. These thresholds were: SDMD of 20 mm, accounting for a minimal penetration of 5 mm into muscle with the standard needle; and 25 mm, which is the length of a standard needle for IM injection, representing the depth this can reach. RESULTS: Cut-point values for arm circumference, at which a longer needle would be required, were higher for males than females: 35 cm versus 30 cm for the 20 mm cut-point, and 40 cm versus 36.7 cm for the 25 mm cut-point respectively. The BMI cut-points were also higher for male than females: 24.6 kg/m2 versus 23.7 kg/m2 for the 20 mm cut-point, and 38.2 kg/m2 vs 31.6 kg/m2 for the 25 mm cut-point respectively. CONCLUSION: Arm circumference and BMI cut-points provide practical measures from which to choose a needle length that increases the chance of successful IM vaccination. Based on our data, an arm circumference of 35 cm for men and 30 cm for women should prompt selection of a longer needle to ensure intramuscular injection at the deltoid site. Thresholds for the different skin to deltoid sites proposed internationally should be determined to enable successful IM vaccination in clinical practice beyond NZ.

The effect of needle length and skin to deltoid muscle distance in adults receiving an mRNA COVID-19 vaccine.

BACKGROUND: The mRNA COVID vaccines are only licensed for intramuscular injection but it is unclear whether successful intramuscular administration is required for immunogenicity. METHODS: In this observational study, eligible adults receiving their first ComirnatyTM/BNT162b2 dose had their skin to deltoid muscle distance (SDMD) measured by ultrasound. The relationship between SDMD and height, weight, body mass index, and arm circumference was assessed. Three needle length groups were identified: 'clearly sufficient' (needle exceeding SDMD by >5 mm), 'probably sufficient' (needle exceeding SDMD by ≤ 5 mm), and 'insufficient' (needle length ≤ SDMD). Baseline and follow-up finger prick blood samples were collected and the primary outcome variable was mean spike antibody levels in the three needle length groups. RESULTS: Participants (n = 402) had a mean age of 34.7 years, BMI 29.1 kg/m2, arm circumference 37.5 cm, and SDMD 13.3 mm. The SDMD was >25 mm in 23/402 (5.7%) and >20 mm in 61/402 (15.2%) participants. Both arm circumference (≥40 cm) and BMI (≥33 kg/m2) were able to identify those with a SDMD of >25 mm, the length of a standard injection needle, with a sensitivity of 100% and specificities of 71.2 and 79.9%, respectively. Of 249/402 (62%) participants with paired blood samples, there was no significant difference in spike antibody titres between needle length groups. The mean (SD) spike BAU/mL was 464.5 (677.1) in 'clearly sufficient needle length' (n = 217) compared with 506.4 (265.1) in 'probably sufficient' (n = 21, p = 0.09), and 489.4 (452.3) in 'insufficient needle length' (n = 11, p = 0.65). CONCLUSIONS: A 25 mm needle length is likely to be inadequate to ensure vaccine deposition within the deltoid muscle in a small proportion of adults. Vaccine-induced spike antibody titres were comparable in those vaccinated with a needle of sufficient versus insufficient length suggesting deltoid muscle deposition may not be required for an adequate antibody response to mRNA vaccines.

Australia needs a vaccine injury compensation scheme: Upcoming COVID-19 vaccines make its introduction urgent.

There is a strong public health ethical justification to introduce a vaccine injury compensation scheme in Australia, and it needs to be in place before widespread use of COVID-19 vaccines.

SARS-CoV-2 Vaccines: Where Are We Now?

The best and safest way to control the coronavirus disease 2019 (COVID-19) pandemic is by using vaccination to generate widespread immunity. The urgent need to develop safe and effective COVID-19 vaccines was met with unprecedented speed and action from the global community. There are now 289 vaccines in the development pipeline. More remarkably, there are 20 publicly available vaccines, and more than 3.3 billion doses of COVID-19 vaccines have been administered across 180 countries. This is just the beginning of our fight against the pandemic. Even at the current vaccination rate, it could take years to vaccinate the world's population; many high-income countries are focusing on their needs, whereas the poorer nations are waiting for vaccines. There is still much that we do not understand about immunity to this new disease, and we will have to contend with the emerging variants. In this commentary, we describe the current status of COVID-19 vaccine development and provide insights into how the development and approvals happened so quickly. We discuss the clinical trial data that led to rapid emergency use authorization and the many challenges of global rollout. We also comment on some of the key unanswered questions and future directions for COVID-19 vaccine development and deployment.

Delayed access to care and late presentations in children during the COVID-19 pandemic New Zealand-wide lockdown: A New Zealand Paediatric Surveillance Unit study.

AIM: Describe paediatricians' experience of adverse health outcomes for children during the New Zealand-wide level 4 lockdown in response to the COVID-19 pandemic. METHODS: Weekly national survey of paediatricians with an open-ended questionnaire. RESULTS: During the 6-week study survey period, the New Zealand Paediatric Surveillance Unit received 33 reports about 55 instances where paediatricians believed care may have been compromised, about half (56%) relating to infants aged from birth to 6 weeks. Compromised care was for acute presentations in 75%, acute complications of a chronic illness in 14%, with 11% for chronic conditions. Paediatricians reported the outcome as moderately severe (short-term morbidity, increased length of stay, higher level of care) in 38 cases (69%) and in a further 4 (7%) as severe (potential to be life-threatening or result in permanent disability). CONCLUSION: Despite clear messaging, hospital avoidance and reduced access to primary and secondary care were associated with significant potential harm for children in New Zealand during a strict lockdown, with newborn infants disproportionately affected. During the implementation of interventions to eliminate community transmission of COVID-19, New Zealand paediatricians note the importance of face-to-face post-natal visits for newborns and primary care services for children with acute illness, to avoid preventable harm.

Vaccines for older adults.

The proportion of the global population aged 65 and older is rapidly increasing. Infections in this age group, most recently with SARS-CoV-2, cause substantial morbidity and mortality. Major improvements have been made in vaccines for older people, either through the addition of novel adjuvants-as in the new recombinant zoster vaccine and an adjuvanted influenza vaccine-or by increasing antigen concentration, as in influenza vaccines. In this article we review improvements in immunization for the three most important vaccine preventable diseases of aging. The recombinant zoster vaccine has an efficacy of 90% that is minimally affected by the age of the person being vaccinated and persists for more than four years. Increasing antigen dose or inclusion of adjuvant has improved the immunogenicity of influenza vaccines in older adults, although the relative effectiveness of the enhanced influenza vaccines and the durability of the immune response are the focus of ongoing clinical trials. Conjugate and polysaccharide pneumococcal vaccines have similar efficacy against invasive pneumococcal disease and pneumococcal pneumonia caused by vaccine serotypes in older adults. Their relative value varies by setting, depending on the prevalence of vaccine serotypes, largely related to conjugate vaccine coverage in children. Improved efficacy will increase public confidence and uptake of these vaccines. Co-administration of these vaccines is feasible and important for maximal uptake in older people. Development of new vaccine platforms has accelerated following the arrival of SARS-CoV-2, and will likely result in new vaccines against other pathogens in the future.

COVID-19 vaccines - are we there yet?

The novel coronavirus SARS-CoV-2, the cause of the COVID-19 pandemic, is a highly infectious human respiratory pathogen to which the global population had no prior immunity. The virus will likely continue to cause significant morbidity until there is a broadly effective vaccine As of mid-December 2020, more than 200 COVID-19 vaccine candidates are in development and 11 have entered phase III clinical trials globally. All generate immunity to the viral spike glycoprotein Three vaccine candidates have agreements for procurement and use in Australia if efficacy and safety requirements are met - one protein-based vaccine, one vaccine using a simian-derived adenovirus vector and one messenger RNA vaccine. The latter two vaccines have published interim analyses and efficacy results of their phase III trials. The messenger RNA vaccine is being rolled out in the UK, USA and Canada Significant uncertainties remain. How well will some of those at highest risk of severe disease (such as older people aged >75 years and those with immunocompromising conditions) be protected by a vaccine, and for how long? Also, to what extent will vaccination protect against infection? This will determine the degree of indirect 'herd' protection needed through broad vaccine coverage of younger age groups.

Active surveillance of acute paediatric hospitalisations demonstrates the impact of vaccination programmes and informs vaccine policy in Canada and Australia.

Sentinel surveillance of acute hospitalisations in response to infectious disease emergencies such as the 2009 influenza A(H1N1)pdm09 pandemic is well described, but recognition of its potential to supplement routine public health surveillance and provide scalability for emergency responses has been limited. We summarise the achievements of two national paediatric hospital surveillance networks relevant to vaccine programmes and emerging infectious diseases in Canada (Canadian Immunization Monitoring Program Active; IMPACT from 1991) and Australia (Paediatric Active Enhanced Disease Surveillance; PAEDS from 2007) and discuss opportunities and challenges in applying their model to other contexts. Both networks were established to enhance capacity to measure vaccine preventable disease burden, vaccine programme impact, and safety, with their scope occasionally being increased with emerging infectious diseases' surveillance. Their active surveillance has increased data accuracy and utility for syndromic conditions (e.g. encephalitis), pathogen-specific diseases (e.g. pertussis, rotavirus, influenza), and adverse events following immunisation (e.g. febrile seizure), enabled correlation of biological specimens with clinical context and supported responses to emerging infections (e.g. pandemic influenza, parechovirus, COVID-19). The demonstrated long-term value of continuous, rather than incident-related, operation of these networks in strengthening routine surveillance, bridging research gaps, and providing scalable public health response, supports their applicability to other countries.