Subcutaneous diphtheria and tetanus vaccines in children with haemophilia: A pilot study and review of the literature

Present status of scheduled vaccinations and vaccination-related bleeding in Chinese children with haemophilia

AIM

Many countries have detailed recommendations for haemophilia patients to reduce the risk of vaccination-related bleeding. However, data from developing countries are lacking. We investigated scheduled vaccinations and vaccination-related bleeding complications in Chinese children with haemophilia and analysed issues related to vaccinations.

METHODS

Children with haemophilia in the PUMCH Haemophilia Treatment Centre were contacted via telephone. We distributed a vaccination questionnaire to their parents. The severity of haemophilia, coagulation factor infusions before vaccination, injection mode, and vaccination-related complications were analysed.

RESULTS

A total of 440 valid questionnaires were received from 27 of 34 provinces in China. 31.3% (138/440) of the children with haemophilia did not receive all of their vaccinations. Among the children who received vaccinations, 48.1% (197/409) experienced bleeding complications. In patients with severe haemophilia, those on regular prophylaxis had a lower incidence of local hematoma compared to those on intermittent or no prophylaxis (14.3% vs. 26.5% vs. 39.7%, P < 0.05). The incidence of local hematomas was lower by subcutaneous (SQ) injections than by intramuscular injections (24.6% vs. 35.3%, P < 0.05).

CONCLUSION

The vaccination rate is quite insufficient in Chinese children with haemophilia. Missed vaccinations are related to vaccination-related bleeding complications. Prophylaxis before vaccination and SQ injections would help reduce bleeding complications.

Safety of intramuscular COVID-19 vaccination in patients with haemophilia

Background

Guidelines recommend that patients with haemophilia should preferably receive vaccination subcutaneously. COVID‐19 and other vaccines, however, are only licenced for intramuscular application.

Aims

To assess the safety of intramuscular COVID‐19 vaccination in patients living with haemophilia.

Methods

Part A of this prospective observational study enrolled consecutive patients with haemophilia A (HA) and B (HB) of all ages and severities and assessed injection site bleeding and other complications within 30 days of vaccination. Part B enrolled patients providing informed consent for detailed data collection including medication and prophylaxis around the time of vaccination. Logistic regression was performed to assess potential risk factors for bleeding.

Results

Four hundred and sixty‐one patients were enrolled into part A. The primary endpoint injection site bleeding occurred in seven patients (1.5%, 95% confidence interval .7–3.1%). Comprehensive analysis of 214 patients (404 vaccinations, part B) revealed that 97% of patients with severe haemophilia had prophylaxis before vaccination, either as part of their routine prophylaxis or using additional doses. 56% and 30% of patients with moderate and mild haemophilia, respectively, received prophylaxis before vaccination. Among the seven bleeds recorded, three occurred when intramuscular vaccination was done without prophylaxis (odds ratio 12).

Conclusions

This is the first prospective study reporting on the safety of intramuscular vaccination in haemophilia. The rate of injection site bleeding was low in mild haemophilia, and in moderate and severe haemophilia if patients received factor prophylaxis.

Consensus statements on vaccination in patients with haemophilia-Results from the Italian haemophilia and vaccinations (HEVA) project

Vaccination against communicable diseases is crucial for disease prevention, but this practice poses challenges to healthcare professionals in patients with haemophilia. Poor knowledge of the vaccination requirements for these patients and safety concerns often result in vaccination delay or avoidance. In order to address this issue, a panel of 11 Italian haemophilia and immunization experts conducted a Delphi consensus process to identify the main concerns regarding the safe use of vaccines in patients with haemophilia. The consensus was based on a literature search of the available evidence, which was used by the experts to design 27 consensus statements. A group of clinicians then rated these statements using the 5-point Likert-type scale (1 = strongly disagree; 5 = strongly agree). The main issues identified by the expert panel included vaccination schedule for haemophilic patients; protocol and optimal route of vaccine administration; vaccination of haemophilic patients with antibodies inhibiting coagulation factor VIII (inhibitors); and vaccination and risk of inhibitor development. This manuscript discusses these controversial areas in detail supported by the available literature evidence and provides evidence- and consensus-based recommendations. Overall, participants agreed on most statements, except those addressing the potential role of vaccination in inhibitor formation. Participants agreed that patients with haemophilia should receive vaccinations according to the institutional schedule for individuals without bleeding disorders; however, vaccination of patients with haemophilia requires comprehensive planning, taking into account disease severity, type and route of vaccination, and bleeding risk. Data also suggest vaccination timing does not need to take into consideration when the patient received factor VIII replacement.