Scientific Committees under CHP discuss use of COVID-19 and measles vaccines
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The JSC reviewed the COVID-19 situation in Hong Kong and noted that relevant surveillance indicators, including the positive detection rate of respiratory specimens and viral load from sewage surveillance, showed an increase in the overall local activity of COVID-19 in the past few weeks, while the number of severe and fatal cases remained stable. Having reviewed the latest epidemiology, scientific evidences of relevant vaccines, recommendations from the World Health Organization (WHO) and overseas vaccination practice, the following recommendations on the use of COVID-19 vaccines were made by experts:
- Booster vaccination for high-risk priority groups in 2024/25
The JSC recommended that the prevailing arrangements could remain applicable. In other words, a booster dose is recommended to be given at least six months after the last dose or COVID-19 infection (whichever is later), regardless of the number of doses received previously, for the following high-risk priority groups for enhanced protection:
- older adults aged 50 or above including those living in residential care homes;
- persons aged 18 to 49 years with underlying comorbidities;
- persons with immunocompromising conditions aged six months and above;
- pregnant women; and
- healthcare workers.
- Use of JN.1 lineage COVID-19 vaccines
Experts reviewed the distribution of SARS-CoV-2 variants from sewage surveillance and human infection cases, and noted JN.1 together with its descendant lineages remained the predominant circulating strains locally. However, there was no information that suggested JN.1 would cause more severe disease. Experts recommended that JN.1 lineage vaccine, when available in Hong Kong, should be used for appropriate persons. Experts reiterated that currently available COVID-19 vaccines (including inactivated virus and mRNA vaccines) remain effective in reducing severe COVID-19 infection and death.
- Simplified arrangements for initial vaccination
Taking reference from the WHO recommendations, the JSC considered the majority of the population had acquired some immunity against COVID-19 during the pandemic and hence recommended to simplify the initial vaccination arrangements. Experts recommended that a person who has never received COVID-19 vaccine is considered to have completed initial vaccination by receiving one dose of mRNA COVID-19 vaccine or two doses of inactivated vaccine, instead of the three initial doses previously recommended.
Details of the interim recommendations are available on the CHP's website at www.chp.gov.hk/en/static/24008.html.
Measles vaccination
The Scientific Committee on Vaccine Preventable Diseases (SCVPD) reviewed the local situation of measles on the same day. Experts acknowledged the two-dose measles vaccination coverage has been consistently maintained at a high level locally, well above 95 per cent, and noted that a local university had recently published results of a research conducted on local measles virus antibodies seroprevalence (2021). Experts also reviewed the results of seroprevalence studies conducted by the DH during 2022 to 2024, showing that the measles antibody level across all ages and specific groups (including foreign domestic helpers, people working or studying in tertiary institutions born outside Hong Kong, and airport workers) attained a level of 95 per cent or above. As such, experts reaffirmed the recommendation for measles vaccination for non-immune adults in Hong Kong published by the SCVPD in 2019, i.e. adults non-immune to measles, including those who had not received two doses of measles-containing vaccines in the past, or have unknown vaccination status or unknown immunity against measles, are advised to consult their doctors and complete their measles vaccination promptly. Moreover, experts also suggested the DH to continue monitoring the measles antibody level of local population.
The CHP reminded members of the public to remain vigilant against COVID-19 locally, and stay alert to the measles situation outside Hong Kong. High-risk individuals should receive vaccination to protect themselves as appropriate.
Ends/Wednesday, July 17, 2024
Issued at HKT 20:11
Issued at HKT 20:11
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