Nearly three years to the day when the latest global pandemic was declared by the WHO, on 11 March 2020, COVID remains a worldwide public health concern. Hygienic practices, social distancing, lockdowns, travel restrictions, mask mandates, mass vaccination programmes, and antiviral medications notwithstanding, COVID has managed to stay ahead in the race to bring it under control.
As of early October 2022, XBB.1.5, a sub-variant of the Omicron variant of COVID-19, had been detected in 35 countries, including Singapore and India, and it has since spread across the world. The precise source of this sub-variant of XBB, itself a recombinant hybrid of Omicron BA.2.10.1 and BA.2.75 sub-lineages, has yet to be identified. China has seen a massive surge of infections caused by XBB.1.5, even as it abandons its Zero-COVID policy and opens up the country to international travel, while there has been a sharp rise in cases in the north-eastern United States. XBB.1.5 appears to bind more readily to surface ACE2 receptors on susceptible human cells, rendering it highly infectious. It is also believed to be highly transmissible and to have successfully evaded protective antibodies from previous COVID infections or vaccinations.
The constellation of COVID symptoms, as identified by the British ZOE COVID Study app and by America’s Centers for Disease Control and Prevention (CDC), includes fever, a runny or blocked nose, loss of the sense of smell or tastes, sore throat, a hoarse voice, sneezing, dry cough, cough with phlegm, shortness of breath, headache, and muscle aches and pains. Some of these symptoms overlap with those produced by other seasonal viruses, including rhinovirus, influenza, and parainfluenza viruses, and also with those of group A streptococcal infection. The true incidence of COVID, in the absence of widespread testing, is thus a matter of conjecture.
Just as the Christmas season has ended, a period of relative COVID inattention has been followed by recommendations from the UK Health Security Agency (UKHSA) that unwell and feverish children should stay away from school or nursery, while unwell adults should also stay indoors, away from the workplace. Travellers from the infection hotspot of mainland China, excluding Hong Kong, will be screened on arrival at London Heathrow and Manchester airports from 5 January onwards, but testing will be voluntary and will not lead to quarantine or self-isolation. These travellers will, however, be required to demonstrate a negative PCR test result 48 hours prior to departure from China.
The UK Government appears to have adopted a laissez-faire approach to the latest surge in COVID cases. As symptoms caused by the variant appear to be generally milder and self-limiting, and as population immunity is believed to be high as a result of cross-protection from previous vaccination, the reinstatement of strict lockdown restrictions no longer seems necessary, but masking in public, the avoidance of indoor mixing, and keeping away from crowded outdoor places is once again being recommended. It may well be that newer bivalent booster vaccines may also help restrain XBB.1.5. The closing chapter in the COVID saga has yet to be written, but it is clear that earlier restrictive containment strategies have mostly been abandoned in favour of less restrictive advisory measures. In the meantime, it is largely left to individuals to decide for themselves what actions are appropriate to their particular circumstances, in the light of advice from the UKHSA and other relevant bodies as and when it is provided.
Ashis Banerjee