Scientific Committees under CHP issue consensus interim recommendations on use of COVID-19 vaccine and monkeypox vaccine in Hong Kong

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17th June 2022 – (Hong Kong) The Scientific Committee on Vaccine Preventable Diseases and the Scientific Committee on Emerging and Zoonotic Diseases (JSC) under the Centre for Health Protection (CHP) of the Department of Health convened an online meeting yesterday (June 16) to discuss the use of the Comirnaty vaccine and monkeypox vaccine in Hong Kong. The consensus interim recommendations have been published today.

The first part of the meeting, which revisited the use of the Comirnaty vaccine, was joined by experts of the Chief Executive’s expert advisory panel (EAP) and the Expert Committee on Clinical Events Assessment Following COVID-19 Immunisation.

 The experts reviewed the situation of myocarditis following the use of the Comirnaty vaccine and noted more evidence suggesting a longer dosing interval between the first and second doses of the Comirnaty vaccine would result in better immune response and lower risk of myocarditis and/or pericarditis. After taking into account the local context, the World Health Organisation (WHO)’s updated recommendation and the latest overseas practices, the JSC-EAP recommended the dosing interval between the first and second doses of the Comirnaty vaccine be extended from three weeks to eight weeks for individuals aged 18 to 59 years. This dosing interval could be shortened to a minimum of three weeks for those with personal needs under informed consent after consideration of individual risk and benefit. The vaccination schedule for other groups would remain unchanged.

In the second part of the meeting, the JSC discussed the use of monkeypox vaccine. The experts noted that Hong Kong has not recorded any confirmed monkeypox human infection cases so far, but confirmed human cases of monkeypox have been reported in some endemic and non-endemic countries and there would be further spread of the virus.

Currently, two types of vaccines are available overseas for use to prevent monkeypox, namely the second-generation smallpox vaccine and the third-generation vaccine. Having reviewed the latest scientific evidence and the recommendations by the WHO as well as overseas health authorities, and taking the local context into account, the JSC considered that mass vaccination is not recommended for monkeypox. First- or second-generation smallpox vaccines are not recommended for use in the context of monkeypox.

 Subject to availability of a monkeypox vaccine, post-exposure prophylaxis for contacts of cases is recommended, in the order of exposure risk from high to low, with an appropriate third-generation vaccine, ideally within four days of first exposure (and up to 14 days in the absence of symptoms) to prevent the onset of disease.

Also, pre-exposure prophylaxis for certain high-risk groups, such as healthcare workers responsible for care of confirmed monkeypox patients and laboratory personnel working with zoonotic pox viruses, could be considered when a monkeypox vaccine is available. Prioritisation would depend on the availability of the vaccine and the situation.

The JSC suggested that the number of doses required, the dosing interval and contraindications for use of a monkeypox vaccine should follow the manufacturer’s recommendations. In principle, one dose would be sufficient in persons with past history of smallpox vaccination and the monkeypox vaccine should be given at least four weeks before or after an mRNA COVID-19 vaccine, if possible.