Suggestions to minimise hesitancy and promote vaccination of children in Hong Kong

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Suggestions to minimise hesitancy and promote vaccination of children in Hong Kong
Jeffrey Chan1; KS Ng, PhD2; Benny YC Hon, PhD3,4; Simon C Lam, PhD, RN5
1 King George V School, Hong Kong
2 Department of Diagnostic Radiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
3 Department of Mathematics, City University of Hong Kong, Hong Kong
4 Department of Psychology, The University of Science and Technology of China, Hefei, China
5 School of Nursing, Tung Wah College, Hong Kong
 
Corresponding author: Prof Simon C Lam (simlc@alumni.cuhk.net)
 
 Full paper in PDF
 
 
To the Editor—Coronavirus disease 2019 (COVID-19) vaccine hesitancy was high initially1 but persists in Hong Kong. As of 2 January 2023, 93.0% and 83.3% of the population had received the second and third doses of the COVID-19 vaccine, respectively.2 However, vaccination uptake for the third dose was only 77.06% for age-group of 12-19 years and 30.92% for those aged 3-11 years.2 The government intends to lower the vaccine pass age limit to 5 years and allow schools to hold full-day face-to-face classes only if 90% of students have received three doses of vaccine before 1 November 2022. According to one study,3 there are four reasons for parental vaccine refusal: religious beliefs, personal beliefs or philosophical reasons, safety concerns, and a desire for more information from healthcare providers. Clearly the reason for the low vaccination rate in Hong Kong is mainly due to safety concerns. The Centre for Health Protection of the Department of Health publishes public health recommendations for the Hong Kong Childhood Immunisation Programme. Advised vaccines from birth onwards include Bacillus Calmette-Guérin, hepatitis B, and diphtheria, tetanus, acellular pertussis and inactivated poliovirus vaccines. Although the side-effects of these vaccines, such as low fever, redness, and a sore arm, are well known, parents do not oppose their administration. We recommend that the Department of Health collaborate with the Education Bureau to implement measures that can improve vaccine uptake. These include: provision of more scientific information, educational and on-site vaccination interventions to schools with a low vaccination rate,4 measures to enhance the biological literacy of school children to encourage vaccination, rapid response by healthcare professionals to dispel rumours and conspiracy theories, education of parents about the benefits of vaccination, and provision of educational seminars via Zoom as continued regular education has been shown to improve the success of vaccination programmes.5 In addition, the Centre for Health Protection may consider other options such as delivering a fractional dose to minimise the side-effects. Another study6 suggests that using an intradermal fractional dose (10-20% the amount of the original dose) vaccination using a microneedle patch can result in better immunogenicity. Side-effects are the most common concern among those who are hesitant or opposed to vaccination. As the safety profile of fractional doses is comparable to that of a regular dose,7 fractional dosages may help combat such hesitancy.
 
Author contributions
All authors contributed to the drafting of the letter and critical revision for important intellectual content. All authors approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
The authors have declared no conflicts of interest.
 
Funding/support
The work of this letter was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region (Project No.: CityU 11303521).
 
References
1. Yu BY, Lam JC, Lam SC, et al. COVID-19 vaccine hesitancy and resistance in an urban Chinese population of Hong Kong: a cross-sectional study. Hum Vaccin Immunother 2022;18:2072144. Crossref
2. Hong Kong SAR Government. Hong Kong vaccination dashboard. Available from: https://www.covidvaccine.gov.hk/en/dashboard. Accessed 2 Jan 2023.
3. McKee C, Bohannon K. Exploring the reasons behind parental refusal of vaccines. J Pediatr Pharmacol Ther 2016;21:104-9. Crossref
4. Gellert P, Bethke N, Seybold J. School-based educational and on-site vaccination intervention among adolescents: study protocol of a cluster randomised controlled trial. BMJ Open 2019;9:e025113. Crossref
5. Akther T, Nur T. A model of factors influencing COVID-19 vaccine acceptance: a synthesis of the theory of reasoned action, conspiracy theory belief, awareness, perceived usefulness, and perceived ease of use. PLoS One 2022;17:e0261869. Crossref
6. Migliore A, Gigliucci G, Di Marzo R, Russo D, Mammucari M. Intradermal vaccination: a potential tool in the battle against the COVID-19 pandemic? Risk Manag Healthc Policy 2021;14:2079-87. Crossref
7. Yang B, Huang X, Gao H, Leung N, Tsang T, Cowling B. Immunogenicity, efficacy, and safety of SARS-CoV-2 vaccine dose fractionation: a systematic review and meta-analysis. BMC Med 2022;20:409. Crossref
 

Time to take action on filicides in Hong Kong

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Time to take action on filicides in Hong Kong
KL Hon, MB, BS, MD1; Karen KY Leung, MB, BS, MRCPCH1; Celia HY Chan, PhD, MSW2
1 Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Hong Kong
2 Department of Social Work and Social Administration, The University of Hong Kong, Hong Kong
 
Corresponding author: Dr KL Hon (ehon@hotmail.com)
 
 Full paper in PDF
 
To the Editor—We previously summarised cases involving filicide in Hong Kong between 2017 and 2018.1 These cases involved children mostly aged <12 years and parents of both sexes with multi-dimensional causal factors.2 Generally, it is crucial to understand the motivation of perpetrators to provide early assessment and intervention. Systematic collection of data on filicide could elucidate these motivations and bring new insights to clinical practice; however, few countries (eg, Australia, Canada) have an official registry on filicide. We recommend setting up an official filicide registry in Hong Kong to investigate the risk factors associated with filicide in Hong Kong in order to inform early assessment and intervention as well as policy decisions. The Comprehensive Child Development Service under Hospital Authority, Department of Health, Social Welfare Department, Education Bureau and Labour and Welfare Bureau aims to identify needs of at-risk children and families in Hong Kong.3
 
Moreover, depression, related to loneliness, helplessness, or hopelessness, is one psychological condition present in those who committed filicides.2 4 Perpetrators might exhibit help-seeking behaviour or filicidal tendencies. Unfortunately, mental health support in Hong Kong is lacking, especially in terms of caregiver support, although it is no substitute for a strong social support network.1 Physicians may have the opportunity to prevent filicide if these warning signs can be detected.5 We recommend development of a multi-dimensional and systematic screening tool to help healthcare professionals in identifying potential cases for filicide risk.1 Physicians, especially psychiatrists, and other healthcare and social service professionals could seize the opportunity to prevent filicide if early warning signs can be identified.5
 
Author contributions
All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
As an editor of the journal, KL Hon was not involved in the peer review process. Other authors have no conflicts of interest to disclose.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Hon KL. Dying with parents: an extreme form of child abuse. World J Pediatr 2011;7:266-8. Crossref
2. Tang D, Siu B. Maternal infanticide and filicide in a psychiatric custodial institution in Hong Kong. East Asian Arch Psychiatry 2018;28:139-43.
3. Education Bureau. Comprehensive Child Development Service. Hong Kong SAR Government 2018. Available from: https://www.edb.gov.hk/en/edu-system/preprimary-kindergarten/comprehensive-child-development-service/index.html. Accessed 21 Sep 2022.
4. Hon KL, Chan CH, Chan L. Filicides in Hong Kong. HK J Paediatr (New Series) 2019;24:48-50.
5. Klier CM, Fisher J, Chandra PS, Spinelli M. Filicide research in the twenty-first century. Arch Womens Ment Health 2019;22:135-7. Crossref

Observations of a locum doctor working at the Asia World Expo Community Treatment Facility

Hong Kong Med J 2022;28(6):503 | Epub 25 Oct 2022
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Observations of a locum doctor working at the Asia World Expo Community Treatment Facility
Alexander Chiu, FHKAM (Medicine), FRCP (Edin)
Community Treatment Facility, Asia World Expo, Hong Kong
 
Corresponding author: Dr Alexander Chiu (subclavian@netvigator.com)
 
 Full paper in PDF
 
 
To the Editor—To combat the fifth wave of the coronavirus disease (COVID) pandemic, the Hospital Authority re-opened the Community Treatment Facility at the Asia World Expo (AWE) in January 2022 to help alleviate the burden on hospitals.
 
Clinical mindset while working at a makeshift hospital requires some modification. For instance, the threshold at which to transfer a deteriorating patient must be lower, since the AWE is not equipped to care for ill patients. For example, there is no piped oxygen supply. Since oxygen cylinders can provide support for only a limited duration when used in high-flow mode, and oxygen concentrators cannot support flow of more than 4 L/min, resuscitation is more difficult at the AWE.1 In the author’s experience, a patient with SaO2 <94% on room air already warrants serious consideration for transfer to another unit.
 
The choice of therapeutics such as intravenous antibiotics will depend not only on the patient’s susceptibility but also on ease of use so that workload for nurses is minimised. An antibiotic that can be injected once daily is preferable to a 12-hourly option; and an antibiotic that can be directly injected intravenously is preferable to one that needs pre-dilution with normal saline.
 
Cough is a prevalent complaint amongst patients attending the treatment facility at the AWE. Chinese herbal medicine provides good symptomatic relief and was welcomed by many patients. For patients with a history of benign prostate hyperplasia, the author will first consult the Chinese Medicine team to establish whether any herbal medicine has the ingredient ephedra alkaloid (麻黃).2 The latter contains ephedrine and may aggravate lower urinary tract symptoms.3 The author learnt from the Chinese Medicine team that the cough remedy “止嗽散合獨參湯加減” contains only a small amount of ephedra, and is safe for use in patients with lower urinary tract symptoms.
 
Setting up the AWE has been complex with many logistical issues. The administration responsible for the setting up of AWE should be commended for their effort.
 
Author contributions
The author contributed to the drafting of the letter and critical revision for important intellectual content. The author approved the final version for publication and takes responsibility for its accuracy and integrity.
 
Conflicts of interest
The author has disclosed no conflicts of interest.
 
References
1. Jain R, Sharma C. Oxygen supply in hospitals: requisites in the current pandemic. Anesth Essays Res 2021;15:253-6. Crossref
2. Zhao W, Deng AJ, Du GH, Zhang JL, Li ZH, Qin HL. Chemical constituents of the stems of Ephedra sinica. J Asian Nat Prod Res 2009;11:168-71. Crossref
3. Balyeat RM, Rinkel HJ. Urinary retention due the use of ephedrine. JAMA 1932;98:1545-6. Crossref

Comparison of the pattern of elderly abuse in Hong Kong before and after the COVID-19 pandemic

Hong Kong Med J 2022;28(6):502–3 | Epub 25 Oct 2022
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Comparison of the pattern of elderly abuse in Hong Kong before and after the COVID-19 pandemic
YF Shea, FHKAM (Medicine); Whitney CT Ip, MRCP (UK); James KH Luk, FHKAM (Medicine)
Department of Medicine, Queen Mary Hospital, Hong Kong
 
Corresponding author: Dr YF Shea (elphashea@gmail.com)
 
 Full paper in PDF
 
 
To the Editor—We have previously published our observations on changes to the pattern of elderly abuse in 2020 (during the coronavirus disease 2019 [COVID-19] pandemic) compared with the pre-pandemic period.1 There was a proportionate increase in physical abuse with the spouse as perpetrator. With the publication of additional data by the Social Welfare Department, we have obtained further data relating to elder abuse between 2014 and March 2022 (n=4293).2 We compared data reported during the COVID-19 pandemic from 2020 to March 2022 (n=996) with pre-pandemic data (from 2014 to 2019, n=3297). The abuse methods and identity of perpetrator were compared using Chi squared statistics. The data are summarised in the Table.
 

Table. Elder abuse data in Hong Kong comparing pandemic (2020-March 2022) with pre-pandemic period (2014-2019)2
 
There was proportionately more physical abuse (71.6% vs 65.9%, χ2=11.0774, P=0.009) but less financial abuse (8.2% vs 16.2%, χ2=39.4716, P<0.001) during the pandemic compared with the pre-pandemic period. Regarding the perpetrators, there were proportionately more spouses (64.8% vs 54.7%, χ2=31.8566, P<0.001). There was no difference in the pattern of elderly abuse or identity of perpetrators within the COVID-19 pandemic period (ie, 2020 to March 2022).
 
We continued to observe proportionately more physical abuse with the spouse as perpetrator during the pandemic. It is likely the initially low vaccination uptake among older adults and COVID-19 outbreak meant the older adults were more likely to remain at home. There were insufficient opportunities for recreational activities or social support. A spouse, often the only co-habitee, had more opportunities to inflict abuse. Government and social welfare organisations should be alerted to this change.
 
Author contributions
All authors contributed to the drafting of the letter and critical revision for important intellectual content. All authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
As an editor of the journal, JKH Luk was not involved in the peer review process. Other authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Ip CT, Shea YF, Chan HW, Luk KH. Changes in pattern of elderly abuse during COVID-19 pandemic. Psychogeriatrics 2022;22:286-7. Crossref
2. Social Welfare Department, Hong Kong SAR Government. Services for prevention and handling of elder abuse. 2022. Available from: https://www.swd.gov.hk/en/index/site_pubsvc/page_elderly/sub_csselderly/id_serabuseelder/.Accessed 12 May 2022.

Vitamin D supplementation to prevent COVID-19 in older people

Hong Kong Med J 2022 Oct;28(5):413 | Epub 21 Sep 2022
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Vitamin D supplementation to prevent COVID-19 in older people
Timothy Kwok
Department of Medicine & Therapeutics, The Chinese University of Hong Kong, Hong Kong
 
Corresponding author: Prof Timothy Kwok (tkwok@cuhk.edu.hk)
 
 Full paper in PDF
 
 
To the Editor—Since the review on the immune modulating effects of vitamin D in coronavirus disease 2019 (COVID-19) infection by Kaler et al1 last year, there has been an open-label trial showing positive effects of vitamin D supplementation in COVID-19 patients in Spain. Out of 838 COVID-19 in patients, 447 were routinely given calcifediol (25-hydroxycholecalciferol) 532 μg on admission, and 266 μg on day 3,7,15 and 30. The treatment group had very significantly lower rates of intensive care unit admission (4.5% vs 21%) and death (4.7% vs 15.9%).2 In contrast, two randomised trials of a single large dose of vitamin D3 on admission in moderate to severe COVID-19 patients have showed no significant benefits.3 The discrepant results may be due to differences in vitamin D formulations. As compared with vitamin D3, calcifediol does not require hydroxylation in liver which is often impaired in acute illness. Therefore, vitamin D supplementation should preferably be started before exposure to COVID-19. Older people who seldom go outside, especially those in old age homes, have high prevalence of vitamin D deficiency. Indeed, an expert group recommended routine use of vitamin D3 1000 units daily in old age homes.4 A randomised trial of vitamin D3 in older people showed that doses up to 2000 units daily for four months was very safe.5 In the midst of the pandemic, I recommend vitamin D3 2000 units once daily in homebound older people to prevent COVID-19 infection and its complications, especially those who are not fully vaccinated.
 
Author contributions
The author contributed to the Letter, approved the final version for publication, and takes responsibility for its accuracy and integrity.
 
Conflicts of interest
The author has disclosed no conflicts of interest.
 
Funding/support
This Letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Kaler J, Hussain A, Azim D, Ali S, Nasim S. Optimising vitamin D levels in patients with COVID-19. Hong Kong Med J 2021;27:154-6.Crossref
2. Nogues X, Ovejero D, Pineda-Moncusí M, et al. Calcifediol treatment and COVID-19-related outcomes. J Clin Endocrinol Metab 2021;106:e4017-27. Crossref
3. Cannata-Andía JB, Díaz-Sottolano A, Díaz-Sottolano A, et al. A single-oral bolus of 100,000 IU of cholecalciferol at hospital admission did not improve outcomes in the COVID-19 disease: the COVID-VIT-D-a randomised multicentre international clinical trial. BMC Med 2022;20:83. Crossref
4. Rolland Y, de Souto Barreto P, Abellan Van Kan G, et al. Vitamin D supplementation in older adults: searching for specific guidelines in nursing homes. J Nutr Health Aging 2013;17:402-12. Crossref
5. Schwartz JB, Kane L, Bikle D. Response of vitamin D concentration to vitamin d3 administration in older adults without sun exposure: a randomized double-blind trial. J Am Geriatr Soc 2016;64:65-72. Crossref

Liver injury associated with the use of health supplement HemoHIM

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Liver injury associated with the use of health supplement HemoHIM
CK Chan, FHKAM (Emergency Medicine), Dip Clin Tox (HKPIC & HKCEM)1; Raymond SM Wong, FHKCP, FHKAM (Medicine)2; Jones CM Chan, FHKCP, FHKAM (Medicine)2; YK Chong, FHKAM (Pathology)3; Jamie Au Yeung, MClinPharm, BPharm (Hons)4; TH Yung, MSc (Clinical Pharmacy), B Pharm in Chinese Medicine4
1 Hong Kong Poison Information Centre, United Christian Hospital, Hong Kong
2 Prince of Wales Hospital Poison Treatment Centre, Hong Kong
3 Hospital Authority Toxicology Reference Laboratory, Hong Kong
4 Hospital Authority Chief Pharmacist’s Office, Hong Kong
 
Corresponding author: Dr CK Chan (chanck3@ha.org.hk)
 
 Full paper in PDF
 
To the Editor—A recent press release issued by the Department of Health of the Hong Kong SAR Government urged public not to buy or consume an oral health supplement “HemoHIM”.1 This product has been withdrawn from the market in Hong Kong, Taiwan and Singapore. In Hong Kong, from April to September 2021, four women presented to public hospitals because of acute hepatitis (Table).2 All patients had consumed a health supplement named HemoHIM (Atomy; Gongju, South Korea) and liver function improved after cessation of use. No alternative medical causes were identified. A sample of HemoHIM was analysed by high-performance liquid chromatography with diode-array detection and liquid chromatography–tandem mass spectrometry, revealing the presence of methoxsalen, psoralen, and benign herbal markers. Subsequent analysis of additional samples from different sources showed consistent laboratory findings. Methoxsalen (also known as 8-methoxypsoralen, 8-MOP) and psoralen are naturally occurring furocoumarins. They can be found in a number of plant species at various concentrations and are collectively referred to as psoralens. Psoralens have photosensitising property, thus methoxsalen is formulated as drugs used in PUVA (Psoralen and ultraviolet light UVA) treatment for psoriasis and vitiligo.3 Psoralens bind to DNA when exposed to ultraviolet light, inhibiting DNA synthesis and causing a decrease in cell proliferation. Methoxsalen- and psoralen-containing herbs have been reported to cause liver injuries.3 4 The listed herbal ingredients of HemHIM should not contain psoralen or methoxsalen. Further investigations are needed to explain the occurrence of these chemical compounds in the product. Several plant species used in traditional Chinese medicine have been reported to contain psoralens,5 including Fructus Psoraleae (補骨脂, the dried seeds of Psoralea corylifolia), which contains a relatively high concentration of psoralens.2 3 Frontline doctors should be vigilant to patients presenting with symptoms of liver injury after consumption of HemoHIM or other supplements containing Fructus Psoraleae.
 

Table. Clinical information of the four cases
 
Author contributions
CK Chan drafted the letter and all authors contributed to the critical revision of the letter for important intellectual content. All authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Hong Kong SAR Government. DH investigates suspected poisoning cases relating to oral product “HemoHIM”. 1 Nov 2021. Available from: https://www.info.gov.hk/gia/general/202111/01/P2021110100785.htm. Accessed 15 Nov 2021.
2. LiverTox: clinical and research information on drug-induced liver injury. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012-. Roussel Uclaf Causality Assessment Method (RUCAM) in drug induced liver injury. Updated 4 May 2019. Available from: https://www.ncbi.nlm.nih.gov/books/NBK548272/. Accessed 15 Nov 2021.
3. Cheung WI, Tse ML, Ngan T, et al. Liver injury associated with the use of Fructus Psoraleae (Bol-gol-zhee or Bu-gu-zhi) and its related proprietary medicine. Clin Toxicol (Phila) 2009;47:683-5. Crossref
4. Li A, Gao M, Zhao N, Li P, Zhu J, Li W. Acute liver failure associated with Fructus Psoraleae: a case report and literature review. BMC Complement Altern Med 2019;19:84. Crossref
5. Guo Jia Zhong Yi Yao Guan Li Ju “Zhonghua Ben Cao” Bian Wei Hui. Zhong Hua Ben Cao (中華本草) [in Chinese]. Shanghai: Shanghai Ke Xue Ji Shu Chu Ban She; 1999.

Paediatric fall deaths in Hong Kong

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Paediatric fall deaths in Hong Kong
KL Hon, MB, BS, MD; Karen KY Leung, MB, BS, MRCPCH
Department of Paediatrics and Adolescent Medicine, The Hong Kong Children’s Hospital, Hong Kong
 
Corresponding author: Dr KL Hon (ehon@hotmail.com)
 
 Full paper in PDF
 
To the Editor—On 22 February 2020, news media reported an unattended 4-year-old girl who fell to her death from a window in her 15th-floor flat.1 The Hong Kong Medical Journal has reported childhood deaths due to accidents and injuries.2 3 4 Injury is a major health problem for Hong Kong children and has surpassed infectious diseases as the leading cause of childhood mortality in Hong Kong.2 5 Approximately 2.9% of children will be admitted to hospital for an injury at least once before their fourth birthday. In a city with many high-rise residential buildings, the risk of falling from height is relatively high, and invariably fatal. Nevertheless, even small falls occurring indoors can lead to severe head injuries or death.6 Preventive measures against childhood injury in Hong Kong are reactive in nature, piecemeal, and usually not subject to evaluation.2 It is recommended that childhood injury prevention be given prime consideration in all policies involving children. Most accidents and injuries may potentially be preventable. Primary prevention by health promotion and public health measures can save lives. Moreover, prompt and effective on-scene cardiopulmonary resuscitation may offer chances of survival and better outcomes for patients after falls.
 
Author contributions
Both authors contributed to the drafting of the letter and critical revision for important intellectual content. Both authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Girl, 4, falls to death from 15th floor flat in Hong Kong, father suspected to have left daughters unattended. Available from: https://www.scmp.com/news/hong-kong/law-and-crime/article/3051828/girl-4-falls-death-15th-floor-flat-hong-kong-father. Accessed 22 Feb 2020.
2. Hong Kong Children Injury Prevention Research Group. Childhood injury prevention in Hong Kong. Hong Kong Med J 1998;4:400-4.
3. Hon KL, Ku AS. Tragic deaths by choking in healthy children. Hong Kong Med J 2019;25:413. Crossref
4. Hon KL, Chan J, Cheung KL. Head injuries after short falls: different outcomes despite similar causes. Hong Kong Med J 2010;16:497-8.
5. Hon KL, Leung TF, Chan SY, Cheung KL, Ng PC. Indoor versus outdoor childhood submersion injury in a densely populated city. Acta Paediatr 2008;97:1261-4. Crossref
6. Hon KL, Leung TF, Cheung KL, et al. Severe childhood injuries and poisoning in a densely populated city: where do they occur and what type? J Crit Care 2010;25:175.e7-12. Crossref

Serological response to mRNA and inactivated COVID-19 vaccine in healthcare workers in Hong Kong: decline in antibodies 12 weeks after two doses

Hong Kong Med J 2021 Oct;27(5):380–3  |  Epub 18 Oct 2021
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Serological response to mRNA and inactivated COVID-19 vaccine in healthcare workers in Hong Kong: decline in antibodies 12 weeks after two doses
Jonpaul ST Zee, FRCPath, FHKAM (Medicine)1,2; Kristi TW Lai, MMedsc (HKU)1; Matthew KS Ho, MMedSc (HKU)1; Alex CP Leung, MMedSc (HKU)1; LH Fung, MPhil3; WP Luk, MPhil3; LF Kwok, BSc (Nursing)4; KM Kee, MPH4; Queenie WL Chan, BScN, FHKAN (Medicine-Infection Control)2; SF Tang, FHKCPath, FHKAM (Pathology)1,2; Edmond SK Ma, MD, FRCPath1; KH Lee, MMedSc (HKU), FHKAM (Community Medicine)5; CC Lau, MB, BS, FHKAM (Emergency Medicine)5; Raymond WH Yung, MB, BS, FHKCPath1,2,5
1 Department of Pathology, Hong Kong Sanatorium & Hospital, Hong Kong
2 Infection Control Team, Hong Kong Sanatorium & Hospital, Hong Kong
3 Medical Physics and Research Department, Hong Kong Sanatorium & Hospital, Hong Kong
4 Quality and Safety Division, Hong Kong Sanatorium & Hospital, Hong Kong
5 Hospital Administration, Hong Kong Sanatorium & Hospital, Hong Kong
 
Corresponding author: Dr Jonpaul ST Zee (jonpaul.st.zee@hksh.com)
 
 Full paper in PDF
 
 
To the Editor—We previously reported serological findings of 302 healthcare workers (HCWs) who completed two doses of mRNA (BNT162b2/Comirnaty; Fosun-BioNTech Pharma) and inactivated COVID-19 vaccine (CoronaVac; Sinovac Life Sciences, Beijing, China).1 Both vaccines were found to be immunogenic in the majority of HCWs. The BNT162b2 resulted in a 11-fold higher level of anti-spike IgG (Abbott SARS-CoV-2 IgG II Quant assay, mean=11572.6 AU/mL vs 1005.2 AU/mL; P<0.001) and a higher surrogate neutralising antibody (sNAb) [GenScript cPass SARS-CoV-2 Surrogate Virus Neutralization Test Kit] positive rate (100% vs 94.4%; P<0.001).
 
We report week 12 serological data of our cohort. Among 197 CoronaVac and 100 BNT162b2 recipients, baseline characteristics of the two vaccine arms were comparable except sex (60.9% and 38% female in CoronaVac and BNT162b2, respectively) [online supplementary Table 1]. There was no difference in anti-spike immunoglobulin G (IgG) positive rate at week 12 (98.5% in CoronaVac vs 99% in BNT162b2; P=1) [Table 1]. Waning of IgG level was observed in both vaccine arms with a larger magnitude of decline in BNT162b2 (-72% vs -64.6%; P<0.001). Despite the more pronounced decline, the median anti-spike IgG of BNT162b2 remained 11-fold higher than that of CoronaVac at week 12 (2840.25 AU/mL vs 253.60 AU/mL; P<0.001).
 

Table 1. Antibody levels after vaccination with CoronaVac or BNT162b2
 
Decline in sNAb was also observed in both arms but the magnitude was significantly smaller in BNT162b2 (-28.3% in CoronaVac vs -2.3% in BNT162b2; P<0.001). Using the manufacturer’s positive cut-off at 30% signal inhibition or above, significantly more CoronaVac recipients had lost their sNAb at week 12 (94.4% sNAb positive at week 2, 62.4% at week 12) whereas 99% of BNT162b2 recipients remained sNAb positive. Throughout the three time points, BNT162b2 arm had higher levels of anti-spike IgG and sNAb (P<0.001) [Fig].
 

Figure. (a) Anti-spike immunoglobulin G (IgG) level; (b) surrogate neutralising antibody level after dose 1 and 2 of CoronaVac and BNT162b2. Each dot represents the antibody level of a participant after dose 1 or dose 2 of CoronaVac or BNT162b2
 
Among the 286 HCWs who had positive sNAb after two doses of vaccine, 64 had lost their sNAb while 222 had sustained sNAb at week 12. Sustained sNAb at week 12 were associated with younger age, BNT162b2 and higher antibody at any time point (Table 2). Multivariate logistic regression analysis showed that only higher IgG and sNAb level at 2 weeks after the second dose were significantly associated with sustained sNAb at week 12 (online supplementary Table 2).
 

Table 2. Factors associated with sustained or lost surrogate neutralising antibody (sNAb) at week 12
 
These results demonstrate rapid antibody decline after both mRNA and inactivated vaccine with a more durable sNAb in the BNT162b2 arm. However, further studies are needed to clarify the impact of waning antibody on vaccine efficacy and protection against severe infection.
 
Author contributions
Concept or design: All authors.
Acquisition of data: All authors.
Analysis or interpretation of data: All authors.
Drafting of the manuscript: JST Zee.
Critical revision of the manuscript for important intellectual content: All authors.
 
All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Acknowledgement
The authors acknowledge the excellent work and contributions by staff at the Clinical Pathology Laboratory of Hong Kong Sanatorium & Hospital.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
Ethics approval
This study obtained ethics approval (Ref RC-2021-07) from the Research Ethics Committee of the Hong Kong Sanatorium & Hospital Medical Group.
 
Reference
1. Zee JS, Lai KT, Ho MK, et al. Serological response to mRNA and inactivated COVID-19 vaccine in healthcare workers in Hong Kong: preliminary results. Hong Kong Med J 2021;27:312-3. Crossref

Antimicrobial resistance in Klebsiella pneumoniae as an independent risk factor for bacteraemia-related mortality

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Antimicrobial resistance in Klebsiella pneumoniae as an independent risk factor for bacteraemia-related mortality
T Meštrović, MD, PhD1,2
1 Clinical Microbiology and Parasitology Unit, Dr Zora Profozić Polyclinic, Zagreb, Croatia
2 University Centre Varaždin, University North, Varaždin, Croatia
 
Corresponding author: Prof T Meštrović (tmestrovic@unin.hr)
 
 Full paper in PDF
 
To the Editor—Although many research endeavours focus on the microbiology, epidemiology, and molecular characterisation of extended-spectrum beta-lactamase-producing and carbapenem-resistant Gram-negative bacteria, few studies aim to assess the impact of these resistance traits on patient outcomes. Therefore, Man et al1 should be applauded for linking antimicrobial resistance in Klebsiella pneumoniae strains with the risk of inappropriate empirical treatment and infection-related mortality.1 The role of empirical antibiotics in septic patients was also highlighted as a key consideration. However, although extended-spectrum beta-lactamase-producing or carbapenem-resistant K pneumoniae isolates were associated with a greater risk of inappropriate empirical treatment, and subsequently with significantly higher 90-day and hospital mortalities, the manuscript would benefit from delineating these two groups of resistant bacteria, as well as from including Pitt bacteraemia scores. Moreover, a paramount study by Patel et al2 showed that even appropriate empirical treatment is often not associated with improved survival among patients with carbapenem-resistant K pneumoniae infections. Also, heteroresistance is an under-recognised phenomenon that may render K pneumoniae strains resistant to antibiotics (despite in vitro susceptibility) and, in turn, confound any steadfast conclusions.3 This is why linking patient-level microbiology data with clinical records and patient outcomes in different settings will be a priority in years to come, as evidenced by trailblazing Global Research on AntiMicrobial resistance (GRAM) Project led by the Institute for Health Metrics and Evaluation (University of Washington) and the Big Data Institute (University of Oxford).4 The highest burden of sepsis-related deaths was already demonstrated in locations least equipped to identify or treat sepsis5; thus, going forward, studies akin to Man et al1 analysing individual-level data will be indispensable.
 
Author contributions
The author had full access to the data, contributed to the letter, approved the final version for publication, and takes responsibility for its accuracy and integrity.
 
Conflicts of interest
The author has no conflicts of interest to disclose.
 
Acknowledgement
The author is involved in the Global Research on AntiMicrobial resistance (GRAM) Project, Institute for Health Metrics and Evaluation, University of Washington, Seattle, United States.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Man MY, Shum HP, Li KC, Yan WW. Impact of appropriate empirical antibiotics on clinical outcomes in Klebsiella pneumoniae bacteraemia. Hong Kong Med J 2021;27:247-57. Crossref
2. Patel G, Huprikar S, Factor SH, Jenkins SG, Calfee DP. Outcomes of carbapenem-resistant Klebsiella pneumoniae infection and the impact of antimicrobial and adjunctive therapies. Infect Control Hosp Epidemiol 2008;29:1099-106. Crossref
3. Band VI, Weiss DS. Heteroresistance: a cause of unexplained antibiotic treatment failure? PLoS Pathog 2019;15:e1007726. Crossref
4. Schnall J, Rajkhowa A, Ikuta K, Rao P, Moore CE. Surveillance and monitoring of antimicrobial resistance: limitations and lessons from the GRAM project. BMC Med 2019;17:176. Crossref
5. Rudd KE, Johnson SC, Agesa KM, et al. Global, regional, and national sepsis incidence and mortality, 1990-2017: analysis for the Global Burden of Disease Study. Lancet 2020;395:200-11. Crossref

Gross negligence manslaughter and hindsight

© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
 
LETTER TO THE EDITOR
Gross negligence manslaughter and hindsight
KY Yuen, MB, BS, MD1; Janice YC Lo, MB, BS, FRCPA2
1 Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
2 Centre for Health Protection, Department of Health, Hong Kong SAR Government, Hong Kong
 
Corresponding author: Dr Janice YC Lo (janicelo@dh.gov.hk)
 
 Full paper in PDF
 
To the Editor—We read with interest the recent Editorial on gross negligence manslaughter.1 The third defendant in “DR” was employed by a clinic. She intravenously administered to healthy clients processed cells originally harvested from the client. The deceased received infusion on 3 October 2012 and passed away on 10 October from multiorgan failure due to septic shock caused by Mycobacterium abscessus. The indictment provided, inter alia2:
1. the therapy was experimental for cancer patients, with unproven or uncertain efficacy;
2. there was no scientifically proven benefit on healthy patients;
3. the preparation involved prolonged culturing of blood cells with risk of contamination.
 
Any intravenous infusion outside a research setting must either be a registered pharmaceutical product of good manufacturing practice standard or comply with stringent quality requirements of a national blood transfusion service. It is foreseeable by any medical practitioner that lack of assurance of sterility would result in microbial contamination. Consideration through hindsight is not involved.
 
The Rose case is distinguishable.3 An optometrist performed routine eye examination for a 7-year-old on 15 February 2012, without retinal examination, which would have revealed papilloedema. Five months later, the boy passed away suddenly. The Court of Appeal quashed the gross negligence manslaughter conviction, as the boy was asymptomatic “with no material pre-existing history” in February; the significance of retinal examination was only realised with hindsight.3 We respectfully submit that the DR decision was consistent with the established gross negligence manslaughter law, with no significant ambiguity. Medical practitioners managing patients in accordance with standard medical practices would unlikely face criminal sanction.
 
Author contributions
Both authors contributed to the drafting of the letter and critical revision for important intellectual content. Both authors approved the final version for publication and take responsibility for its accuracy and integrity.
 
Conflicts of interest
All authors have disclosed no conflicts of interest.
 
Funding/support
This letter received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
 
References
1. Leung GK. Medical manslaughter: the role of hindsight. Hong Kong Med J 2021;27:240-1. Crossref
2. HKSAR v Mak Wan Ling. HKCFI 3069; 2020. Available from: https://legalref.judiciary.hk/lrs/common/search/search_result_detail_frame.jsp?DIS=132426&QS=%28mak%2Bwan%2Bling%29&TP=RS. Accessed 23 Aug 2021.
3. Regina v Rose HM. EWCA Crim 1168; 2017. Available from: https://www.bailii.org/ew/cases/EWCA/Crim/2017/1168.html. Accessed 23 Aug 2021.

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