Previously, only those in high-risk groups or who had taken the less-effective Sinovac shot were eligible for boosters. Studies in several countries have shown that boosters significantly aid in the fight against the more infectious Omicron variant.
Hong Kong has proved effective in keeping out the Delta variant; it is one of the few places in the world to have avoided a Delta outbreak. There have been no locally transmitted cases of Covid for more than six months.
However, this has led to complacency over vaccination, with less than 70% of the city’s population being inoculated with at least one dose. One-third of those have had the Sinovac vaccine, which provides insufficient protection against Omicron even with three shots.
Hong Kong would be vulnerable if Omicron took hold, and it is increasingly being detected in travellers. As of January 4, 114 cases of Omicron have been detected at the airport, all arriving passengers or directly linked to them. On December 23, the government said an airport cleaner was suspected of having been infected with Omicron, the first time the variant appears to have evaded the city’s strict border controls.
Hence the expansion of boosters. The government has also started making second doses of the Pfizer-BioNTech vaccine available to 12-17-year-olds. Younger people had previously been restricted to one shot due to concerns over the side effect of myocarditis.
Hong Kong’s booster programme will be watched in China and much of the developing world, where millions of doses of Sinovac’s vaccine have been administered. That is especially true for the mainland, where the Lunar New Year (February 1) and Beijing Winter Olympics (February 4-20) pose particular opportunities for Omicron to take hold.
Plans to reintroduce limited quarantine travel between Hong Kong, Macau and the mainland ahead of February may now be scaled back or postponed. Or Hong Kong may have to adopt the tight monitoring of its citizens commonplace on the mainland, which has used all the tools of its surveillance network to tackle the outbreak.