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Responses to SARS-CoV-2 vaccines in different populations are important to define efficacy. Here the authors show using a cohort in Singapore that two doses of mRNA vaccine is less effective in recipients over 60 years of age and that a further dose of vaccine can improve these antibody levels.

The emergence of new SARS-CoV-2 variants, such as the more transmissible Delta and Omicron variants, has raised concerns on efficacy of the COVID-19 vaccines. Here, we examined the waning of antibody responses against different variants following primary and booster vaccination. We found that antibody responses against variants were low following primary vaccination. The antibody response against Omicron was almost non-existent. Efficient boosting of antibody response against all variants, including Omicron, was observed following a third dose. The antibody response against the variants tested was significantly higher at one month following booster vaccination, compared with two months following primary vaccination, for all individuals, including the low antibody responders identified at two months following primary vaccination. The antibody response, for all variants tested, was significantly higher at four months post booster than at five months post primary vaccination, and the proportion of low responders remained low (6-11%). However, there was significant waning of antibody response in more than 95% of individuals at four months, compared to one month following booster. We also observed a robust memory B cell response following booster, which remained higher at four months post booster than prior to booster. However, the memory B cell responses were on the decline for 50% of individuals at four months following booster. Similarly, while the T cell response is sustained, at cohort level, at four months post booster, a substantial proportion of individuals (18.8 – 53.8%) exhibited T cell response at four months post booster that has waned to levels below their corresponding levels before booster. The findings show an efficient induction of immune response against SARS-CoV-2 variants following booster vaccination. However, the induced immunity by the third BNT162b2 vaccine dose was transient. The findings suggest that elderly individuals may require a fourth dose to provide protection against SARS-CoV-2.

Routine mammography screening is currently the standard tool for finding cancers at an early stage, when treatment is most successful. Current breast screening programmes are one-size-fits-all which all women above a certain age threshold are encouraged to participate. However, breast cancer risk varies by individual. The BREAst screening Tailored for HEr (BREATHE) study aims to assess acceptability of a comprehensive risk-based personalised breast screening in Singapore. Advancing beyond the current age-based screening paradigm, BREATHE integrates both genetic and non-genetic breast cancer risk prediction tools to personalise screening recommendations. BREATHE is a cohort study targeting to recruit ~3,500 women. The first recruitment visit will include questionnaires and a buccal cheek swab. After receiving a tailored breast cancer risk report, participants will attend an in-person risk review, followed by a final session assessing the acceptability of our risk stratification programme. Risk prediction is based on: a) Gail model (non-genetic), b) mammographic density and recall, c) BOADICEA predictions (breast cancer predisposition genes), and d) breast cancer polygenic risk score. For national implementation of personalised risk-based breast screening, exploration of the acceptability within the target populace is critical, in addition to validated predication tools. To our knowledge, this is the first study to implement a comprehensive risk-based mammography screening programme in Asia. The BREATHE study will provide essential data for policy implementation which will transform the health system to deliver a better health and healthcare outcomes.

Abstract Objective Despite the high vaccine efficacy of mRNA COVID‐19 vaccines, there are individuals who developed excessive reactogenic and/or allergic responses after the first mRNA dose and were considered ineligible for further mRNA doses. CoronaVac, an inactivated SARS‐CoV‐2 vaccine, is recommended in Singapore as an alternative. Methods Individuals, ineligible for further mRNA vaccines (BNT162b2 or mRNA‐1273) because of excessive reactive responses to prime mRNA vaccination, were recruited and offered two doses of CoronaVac as booster vaccination 38–224 days post their mRNA vaccine dose. Individuals who did not develop any excessive reactive responses after the prime mRNA vaccination were also recruited and given another mRNA vaccine as booster vaccination. Blood samples were collected at days 0, 21 and 90 post first CoronaVac dose and mRNA dose, respectively, for analysis. Results We showed that two CoronaVac booster doses induced specific immunity in these mRNA vaccine‐primed individuals. Although the spike‐specific antibody response was lower, their memory B cell response against the receptor‐binding domain (RBD) of the spike protein was similar, compared with individuals who received two BNT162b2 injections. The spike‐specific memory T cell response also increased following CoronaVac booster doses. However, specific immunity against the Omicron variant was low, similar to individuals with two BNT162b2 doses. Conclusion Our findings showed that while mRNA vaccine‐primed individuals can opt for two subsequent doses of CoronaVac, an additional dose may be necessary to achieve protection, especially against newly emerging immune escape variants such as Omicron.

Abstract Background The World Health Organization has highlighted the paucity of research into the oral health needs of older adults. In Singapore, until recently, publically funded/subsidized oral health care for adults has been limited to basic primary care at government-funded polyclinics. Access to a more comprehensive range of subsidized care in the private sector was widened through the government-funded Community Health Assistance Scheme (CHAS) in 2012 and Pioneer Generation (PG) scheme in 2015. Little is known about the attitude to dental service utilization among older adults in Singapore since then. Methods We conducted semi-structured individual interviews with 25 participants above 65 years of age who were eligible for subsidized dental care plans. Participants were recruited from a public teaching hospital and a public primary care clinic in Singapore. The duration of each interview was 15–30 min. Interviews were transcribed verbatim and the transcripts were analyzed thematically using a phenomenological approach. Results Pertinent themes emerged related to four major areas: (a) general awareness towards oral health, (b) life course perspective of oral health, (c) barriers to visit the dentist, (d) shaping dental service utilisation behaviours through provision of financial subsidies for dental care. Most participants perceived a strong relationship between oral health and systemic health. However, there were erroneous traditional beliefs such as oral health is not part of physical health and edentulous participants did not need to visit a dentist. Fear, anxiety, previous negative experience and lack of knowledge were barriers to visiting the dentist. Trust and convenience were considerations for patients when deciding whether to switch from public to private dental services where CHAS/PG were only available. Conclusion Our study provided important insights regarding oral health perceptions and beliefs of older people residing in the community which may affect their dental service utilization. This further highlights the importance of understanding the concerns of this group when implementing healthcare policies for elderly in Singapore. The findings of our study will serve as a baseline for future studies in Singapore and inform studies in other countries that implement targeted schemes for older adults.