Time for Hong Kong to face Omicron reality and make vaccines mandatory
- Hong Kong’s pandemic measures need to be reassessed in light of what we know about the Omicron variant, vaccine science and the impact of the city’s policies
The reproductive number, or R0, of the original Covid-19 strain was around 2.79. This means that one case would infect 2.79 people. The Delta variant has a higher R0 of around 5.08, ranging from 3.2 to 8 across studies. This R0 is higher than that of smallpox or pandemic flu.
The R0 of the Omicron strain is thought to be about 3.3 times that of the Delta variant, or around 16. If this R0 is confirmed, there will be little to no chance of stopping a massive spread. Omicron will become the dominant variant globally.
Immunity from vaccination will decrease the R0 provided that the vaccine is effective against the circulating variant and enough people have been vaccinated. It is unclear how effective the current vaccines are against the Omicron variant. Current evidence suggests they are less effective in preventing transmission but are still effective against the virus causing severe disease and death.
New vaccines are being developed. In many countries, vaccination against several infectious diseases is legally required.
In Hong Kong, around 70 per cent of the population has two Covid-19 vaccinations and about 9 per cent of the population has a third or booster vaccination. Vaccination against Covid-19 should, in my view, be made mandatory in Hong Kong.
New drugs including molnupiravir, which can be given orally, or remdesivir or monoclonal antibodies could all be given to early Covid-19 cases who are considered at high risk of developing severe disease. They will decrease the number of cases of severe disease and reduce mortality. There is also early evidence, still to be confirmed, that Omicron causes less severe disease than other variants.
The pandemic has caused enormous psychological and economic burdens because of the Hong Kong government’s strict measures designed to stop the spread of Covid-19. Hong Kong has consequently been one of the safest places to live in the world throughout this pandemic.
However, these measures now need to be reassessed. We need to balance the mental and economic burdens against the true risk of severe disease and death.
We must take into account that the Omicron variant might not be that severe, that we will probably be unable to stop Omicron from becoming epidemic in Hong Kong, that we have new drugs to prevent severe disease and that it is in the power of the Hong Kong legislation to achieve vaccination rates close to 100 per cent.
Dr John Simon, Central